13th March 2017
I've been busy over the last 3-4 weeks doing a lot of Commodore repairs that came in.
Here's a quick run down of the problems and what was done.
Commodore 64 faulty power switch repair
Very common problem, the switch works sometimes and sometimes not. Easy to fix, just replace the switch. Problem is we're about 30 years too late
to buy the parts now. I found a similar switch online and bought it hoping it would be a simple drop-in replacement. It almost is, but the plastic rocker
was too big. Luckily the design is similar and the plastic rocker can be swapped with the original one and fits ok. So I swapped
everything over, inserted the switch into the PCB then errr, it didn't push down fully. I got out my trusty hacksaw and chopped off the bottom part
of the bracket which isn't needed anyway and now it fits perfect. Soldered it in and it's working fine.
Commodore 1084S-P monitor repair
It was just making a whining sound and the power light was off. That's a classic sign of an internally shorted flyback. Luckily, replacement
reverse-engineered flybacks for *some* monitors are still available from a company called HRDiemen. I pulled the flyback out, ordered a new
one from a local distributer, soldered it back in, adjusted all the various potentiometers etc and it's working just fine now. One word of
caution regarding these replacement flybacks, I have bought many of them over the years and every one has been shipped with the screen
control pot turned up full. That basically over-volts the neck board and tube RGB guns by 2 to 3 times and can blow up the neck board or
tube or both. If you fit one of these new flybacks, be sure to turn the screen control pot all the way down (maximum turn counter-clockwise)
then adjust it as required.
Commodore Amiga 600 repair (and rant about caps)
This had a fault where it would take about 10 minutes to power on. After that it would work fine until powered off, where it would then take
another 10 minutes to boot-up again. That usually means bad capacitors. Sure enough when looking around there was leaky caps in the reset
section and some corrosion. When it did work the sound was strange too. If you check the first photo (below) you can see the crud build-up on
the SMD op-amp chip, which explains at least part of the sound issue (more on that later). First thing to do is remove all the affected
parts, then clean up the PCB, check for track damage (there wasn't any) then replace all the parts with new parts. The owner had previously
bought a cap kit from a popular Amiga part supplier in UK (ending in 'kit') but was not confident enough to do the job himself so he
provided that to me so I could swap over all the caps. I replaced the first two bad caps in the affected area and the other things such as
SMD resistors/caps/transistors etc and the op-amp IC, powered on but that didn't fix the booting issue. The sound issue appeared to be
slightly better but still not right. I then consulted the schematic and found that the section that was damaged is actually the
amplification circuit. Well at least that should be fixed now hehe! The reset IC (LM555) is tied to a smaller electrolytic 10uf cap so I
changed that and it vastly improved the power-on time from 10 minutes to about 1 minute. An improvement sure, but not good enough! The Amiga
should of course power on instantly. When it was working, I also noticed the sound on the left side of the monitor was lower in volume than
the other side. That is generally a cap problem too with the caps connected to the outputs near the RCA jacks. So then I proceeded to
replace the remaining caps on the board since I had the cap kit anyway. After replacing all the electrolytic caps I noticed the sound
problem was solved but the computer was still not booting up immediately like it should be doing. It also sometimes would not see the HDD. I
checked the 44-pin HDD connector and found a couple of loose pins. The connector was damaged so I have ordered one to replace it (currently
waiting for it to arrive). With my logic probe I could see the output on the reset chip was not firing. I checked the schematic again and
noted there are a number of SMD parts in the reset section connected to the 555 timer, located on the top side and bottom side of the
I pulled each part and tested them and they were all OK. The only part I had not checked was the "new" 10uf electrolytic cap at
location C612 that I had replaced from the cap kit. So I pulled the cap and tested it and found it to have an ESR reading of 4.2ohms. That
is WAY too high for a cap in the reset section, about 3-4 times out-of-spec for the 10uf 35v cap which was supplied. I grabbed a quality
Matsushita/Panasonic high temp low ESR "FR" range cap from my spare parts stock (which is basically the highest specification cap available
from that company), swapped that over then powered on and BAM! it powered on immediately. Problem solved! So the moral of this story is use
only low ESR caps in the reset section and beware of companies/people who sell cheap cap kits. Cheap as in "cheap caps", not cheap as in
"cheap price". The cap kit provided was certainly not a cheap price but the caps are definitely cheap Chinese crap caps. Always buy quality
Japanese electrolytic caps when working on repairs of expensive or uncommon electronics, otherwise you'll be sorry. There are really only a
few that are guaranteed for 10+ years and they are all made in Japan. Most of them will last 30+ years. They are made by Nichicon, United
Chemi-con, Matsushita/Panasonic, Rubycon and a few others. If you are interested, you can google 'bad caps' and read all about cheap
rubbishy caps that have become famous on sites like badcaps.net so you can avoid them! Unfortunately that site now requires an account to
view forum posts so I can't recommend it. There is another site that has a full list of every brand with photos and info at
http://capacitor.web.fc2.com. This site allows you to identify the brand of any cap (including cheap caps). The site is in Japanese but you
can use google translate or the Chrome browser to auto-translate it. The site is *very* informative so it is worth the effort to do some
Do yourself a favor, when buying electrolytic caps for quality electronic equipment, only get them from official channels like Mouser,
Digikey, Element14, RS etc and choose the quality Japanese brands (they usually sell several other brands too). You will also save money
because other companies and sellers just buy them from places like that (usually selecting the cheapest brand they can get away with), mark
them up and re-sell them for a profit. Otherwise you're probably buying cheap Chinese caps that will fail in a year or two and possibly
damage your rare collectable equipment. Those companies and individuals are only there to make money and will do whatever it takes to save a
few bucks. To give you an idea, a cheap cap costs 10c, the good quality version costs 65c. That's a difference of 55c. That may not sound
like much to you and me, but in quantites of 1000 it's an extra $550, and of course they are there to make money so they cheap out and use
crappy caps. Don't buy them from eBay either because the Chinese cap companies have copied all of the brands and sell them as genuine good
caps when in fact they are cheap copies with the same branding marks!
If you do want to buy a cap kit ask the seller what brand caps it has. If they are reluctant to tell you or they don't know or they just say
they are using the best quality caps available, it's almost certain they are using cheap caps. If you have caps already and want to know if
your cap is good use an ESR meter to test it (available on ebay for a small price), then refer to the standard ESR charts floating around
the net to see if the cap is good or bad. The uF reading should be within +-5% of the number printed on the capacitor and the ESR should be
within the specification on the chart. The actual ESR depends on the voltage rating of the capactitor and the uF so you need to refer to the
chart to know if it's good or bad. Only use caps within specification and toss out-of-spec caps in the bin where they belong. The Amiga
deserves only the best and only Amiga makes it possible!
Commodore CBM 4016 repair
This one took a few weeks to figure out. It would boot up and work, but then lock up at some random time. Sometimes it would run for 3
minutes, or 30 minutes, or 3 hours. If I powered off then on it would work again perfectly for some random amount of time. Sometimes when it
crashed it would drop out to the built-in machine code monitor. Other times while running a simple basic program it would stop with a
"syntax error" and just one character had been changed to a 4x4 checkerboard pattern symbol. After fixing the error it would run again until
it crashed again later. It was crazy! When it ran long enough to run a software RAM test, it didn't find any errors. The voltages were ok so
it wasn't a power supply issue. The board was really gross too. Some idiot had sprayed silicon spray all over the board and it was a really
nasty slippery slimy thing to work on. The first thing to do was clean it up so I removed all of the socketed chips and gave it a bath
in soapy water, rinsed in clean water then dried it off outside in the sun for 1 whole day. After that I replaced all of the old MOS mask
ROMs with EPROMs (2532 are directly 1:1 compatible) and changed all of the 37 year old single-wipe sockets for new dual wipe sockets
including all of the larger 40 pin sockets. Removing the sockets also meant I could clean the crud off the board under the socket too.
Changing the ROMs & sockets didn't help but one of the ROMs was unknown and undumped!! It was the editor ROM for a 50Hz, graphic keyboard,
80 column type PET which is not available on the net. I promptly sent that to the master PET ROM archive at zimmers.net for safe keeping :-)
Next step was to change all of the 4116 DRAMs. They are also 37 years old and I figured at least one of them was bad or soon will go bad so I
ordered 16 new (old stock) DRAMs and new dual-wipe sockets and just replaced everything. I wanted it to be stable and reliable for many
years to come so there's really not much point trying to diagnose if one or two RAMs are bad, better to just change it all and be done with
it. While doing that I realized that this machine was a 16k, 80 column board which had been upgraded to 32k by someone who was not very good with desoldering
parts and had damaged the board under the chips. That explains the amateurish patch wire the size of fence wire on the bottom side of the board under
the RAMs! With all of the RAM removed I traced all of the RAM tracks and found no other track damage. Even after changing all of the RAMs it
still wasn't working properly but with all of that changed at least now I knew the problem was not ROM or RAM related.
I powered it on the next day and it was totally dead! After testing some things I realised the syncs on the 6845 were missing. The input
clock was there but no syncs, and since they are outputs it had to be a bad 6845. I changed it and the computer sprung back to life with the same
fault as before. So the 6845 just died on me in the middle of the repair!
All of the caps were 37 years old too, so the next thing was to replace all of the caps. Still no improvement on the actual lock-up issue so
I figured I had a logic problem. Over the course of about another week I slowly checked each chip but it wasn't an easy task because most of
the time it was working and when it locked up everything would stop. Powering off/on would make it work again perfectly for some random
amount of time. In the end I consulted the schems and started just changing all the logic in the memory control section since that too was
all 37 years old. In reality it needed all of the logic replacing but that was a huge job. After replacing about 1/2 of the logic the whole
thing just died again and this time it was permanent. There were no clocks anywhere (not even on the CPU) but the main crystal was ok. Most
of the time it wouldn't boot at all but when it did (once in dozens of power-ups) it locked-up within 1 second and the monitor would make really
bad noises like it was out of sync and receiving the wrong frequency. That allowed me to narrow down the search to the clock generation
circuit. I eventually found the bad chip, a 74LS164 at location UE3. I tested it in my IC tester and it failed. After
replacing that chip it fired up immediately and continued to work for the rest of the day without any issues so I knew it was fixed 100% :-
I wanted to see if the PET experience could be better so I looked around on the net and found a replacement ROM that has been reverse
engineered from the original ROM with additional features. These include Escape key sequences, a soft reset (like CTRL-ALT-DEL on a pc), a
DOS Wedge and a 40/80 column soft switch mode. I burned a new EPROM, fitted it and it had some issues so I contacted the maintainer and he promptly fixed the
problems and sent me a new binary and it worked great! If you have a PET and are interested in adding more features like I mentioned above
check out the site here
Commodore Amiga Power Supply 391029-05 Repair
This is one of the myriad of Amiga power supplies made by Commodore, model 391029-05 and is one of the light switch-mode power supplies.
When powered on it appeared to be working but when powered off it would make a whining sound that would get lower in tone over about 5
seconds before stopping completely. I suspected the caps so I opened it up and found several bad caps that had bulged and leaked. They had
also leaked through to the bottom side of the PCB causing some corrosion. I removed all of the caps, cleaned up the board and replaced all
of them with good new caps. The noise issue was still there but for only 1/4 of a second so I figured it was normal. I believe the noise is
the switching transistor trying to run but because the AC has been turned off, the large filter cap drains quickly and makes some noise via
the transformer winding. I don't know if that was by design or not, but it's actually a good thing because the big filter cap is totally
discharged. I measured it after running it for a while then powering off and the big filter cap had no charge in it. In any case the tiny
1/4 second noise is not a fault. I've heard a similar sound when turning off some electrical appliances. I tested the output voltages and
found there were none! After about 2 minutes the voltages measured ok! So there was a delay in the power supply starting up. But it couldn't
be caps because I just changed them all with exactly the same values that were in there. Or could it? I checked an identical Amiga power
supply and found that some of the caps were a different value! I changed them for the other type and it fired up immediately. I checked the
caps I removed and they measured OK so they were just the wrong value and likely changed by some amateur years ago. At that point I was
curious what the caps did so I went looking for a schematic of this power supply on the net and found nothing. So then I looked for *any*
Amiga power supply schematic and found nothing! That just isn't right so I decided to reverse this one and make a schematic of it to see how
it works. After a few days it was done. Below is the schematic for this power supply (391029-05) which I am making available for the benefit
of the Amiga community. The schematic might look a little bit strange but that is by design. The PCB has no component locations or markings
so it makes it difficult to reference components between the schematic and PCB. The schematic is drawn using the same track layout as the
PCB, but viewed from above. Think of the PCB as being transparent and you can see the tracks below. That way you can look at the components
on the PCB and immediately know where to find them on the schematic. It is also drawn on an A0 sheet because I really hate multi-page
schematics. If you have ever tried to fault-find an Amiga motherboard using the available Commodore schematics you will know how much of a
pain it is to look through 18 pages trying to find a signal only to find it then goes off somewhere else and then you have to find that
signal, then off somewhere else etc etc etc. Drawing it on one very large sheet solves that problem. In today's computing world, multi-page
schematics are really a thing of the past in my opinion. For those who are curious, the schematic was drawn using Altium Designer version
It would be good to continue to make more Amiga power supply schematics but the other versions are not available to me here. If you are
reading this and want to help, you can. If you have any of the other versions of the Amiga power supplies (heavy or light versions, dead or
alive) or any other Amiga hardware that doesn't have any schematics available and you would like to see them reverse-engineered so a
schematic can be created and made publicly available, contact me. Even if you can't help directly, you could
help by informing other Amiga users on any of the Amiga forums and similar places so that my request gets out there. You can also help by
simply donating via Paypal or donating any other unwanted Amiga or Commodore hardware. Hopefully I will be able to get hold of more Amiga
power supplies (or other hardware without schematics) and make schematics for all of them. That will benefit everyone who owns a real Amiga
so they can continue to live on! :-)
I'm also looking for a yoke from a 1084 or 1084S or 1084S-P or 1084S-P1 monitor (or possibly a 1081 may also fit). Basically any of the
models made by Philips should work ok.
I was given a dead and rusted 1084S-P1 a while ago. The chassis repair took a long time to fix because of all the corrosion but now works
fine. The repair will be shown in a future news post. Unfortunately the yoke is shorted and corroded so it's currently still unusable. If you
have any faulty/not-working Commodore monitors and you want to part out some pieces please contact me.
21st February 2017
Some more decapping news! My Sega Model 1 DSP's were decapped and the ROMs have been successfully extracted. More news on the CAPS0ff blog. Please support CAPS0ff with funds if you can so more chips can be decapped.
Those chips have also been marked green on my Decapping Status Page
16th February 2017
I redumped Gallop Racer 2 and now it's working in MAME. Here's a few screenshots....
This next pic shows the PCB in the Mother-Load that is shown on 15th July 2016.....
26th January 2017
At my request, CAPSoff has decided to consider decapping chips that are still sitting here in my Guru Lair or other chips that may be
acquired in the future.
Because of the costs involved with decapping and processing chips, to do all of the current chips and any future ones that come along, they would
like to get some support from the emulation community in order to keep the project moving forward. You can
read about it on their blog here.
They also recently did some decapping work on some PIC16C57 chips and you can see their blog entry about that here.
7th January 2017
A few years ago around the middle of 2009 I received some items for decapping. Technically they were not really needed but they were sent anyway.
However this was an extreme case of severe butcherism because the chips were received like this.....
The PCB was also sent, minus most of it's chips!
Clearly this was scrap, or so I initially thought, so I basically tossed it on my pile of junk and it sat there for several years.
We all now know that the chips were not really needed for decapping because the emulation is working fine thanks to fantastic reverse-engineering
work by Bryan McPhail. It always disturbed me that this PCB was treated so badly and was scrapped for no good reason. Recently I came across it
while looking for some other stuff and I decided to make an attempt to resurrect it to it's former glory.
The first thing was to determine if all the chips I needed were available. After a bit of searching I found all of the custom chips except
the HuC6280, but I had a couple of spare chips lying around so I had that missing chip in stock. There were several other chips missing including
several SMD logic chips, a YM2151 sound chip, a few SMD capacitors, an electrolytic capacitor that feeds the reset circuit and a DIP8 EEPROM.
And of course all of the ROMs were also missing. I had all of those parts either in my parts bin or on some scrap PCBs and the ROMs can
easily be replaced with EPROMs so the re-assembly work could begin!
The next step was to clean all the old solder off the PCB pads where the missing chips were. It was a pure miracle that the fragile solder
pads were not broken or ripped off the board by the idiot who did all this damage. It's an easy job to remove solder so after an hour that
part was done.
Now came the really tedious and boring part.... I had to bend all of the legs on every custom chip back to where they
were supposed to be *very carefully*, hoping the legs were (a) all present and (b) didn't break off as I manipulated them. After many hours
(about 1 hour per chip) the job was done and everything looked as good as it could get... not perfect but very close.
Now to start mounting the chips. I started with the logic chips, capacitors and other smaller parts then moved onto the custom chips. One by
one they were soldered into place. Because the chips were not perfectly straight and flat within 0.1mm (the normal tolerance) I had to mount
each leg one by one (close to 800 legs!). I couldn't do the usual drag soldering method and mount the chip quickly. Every leg had to be held
in place carefully in line with the PCB pad and then heated with the soldering iron to make it stay there. Because I worked in
engineering for 30 years I have developed special tools to help with that kind of task so it went fairly smoothly. After many many hours
(maybe 24 hours across about 3-4 days) everything was in place and it was time to power on and see if it was alive.
The first screen I saw was full of garbage tiles so I thought it was not working, but looking closely at the screen I could see some white
text among the pink, blue, white and purple mess that read..... "WARNING GAME MODE SETTING ERROR"
By luck probing around, I accidentally shorted two pins on a logic chip near the CPU and to my amazement it booted into the game! The
backgrounds were scrambled but it was running! The title screen graphic "Fighter's History" was there but the "Copyright Data East 1993"
text was also scrambled, mostly just random dots. Most of the initial Data East logo first boot screen was also OK but some sections were
out of position. All of the sprites were OK. The game was playable (i.e. controls were working so I assumed the custom I/O chip was OK) and
sound was working too. Things were starting to look very promising!
I figured some legs on the custom chips were loose so I went around every chip and checked them and found a couple of loose legs. The
graphics were improved slightly but it was still not fixed so I started looking closer at the bottom of the PCB. Because this board had been
attacked with a heatgun there were many solder blobs on the board where the solder in the vias had come out of the hole (because it was
boiled) and was sitting on the PCB surface as a little solder ball. You can see some of the little balls in the 11th pic shown above (the
PCB pic with the blue resitor array pack). There were dozens and dozens of those little balls all over the PCB top and bottom. This
particular PCB has vias that are *really* close together and some of the solder balls were causing shorts. I cleared most of them before I started
soldering the custom chips on but missed a few. After clearing some more blobs it improved a bit more. The corruption seemed to change
slightly with each re-boot. I checked a few logic chips connected to the 56 and 74 chips (used for generating the backgrounds) and found a
74F373 SMD logic chip that was a bit random. I pulled the chip and tested it and found it passed the test only about 50% of the time so it
was faulty. This was probably the original fault as I'm guessing this board came off ebay. After changing it the graphics were no better but
at least now the corruption was consistent.
The pic above shows the backgrounds are now partly correct.
At this point I needed to get some confirmation about a few things so I contacted Bryan to get his opinion. MAME is really great for playing
games but there's very little real world repair info in MAME (aside from my Guru-Readme's hehe!) to help with problems like this. At least
not for the average person who doesn't understand the deep down guts of the code and how it works. He told me the bootup warning error means there is a
problem with the 93C45 EEPROM and the graphics fault was likely shorted or loose pins on the background graphics chips. In this case that's
chip 56 and/or 74.
On a regular board a bad line will usually give a solid bad line/jailbar on the graphics. But on Fighter's History the graphics chip uses
a form of encryption that mixes up all the bits within a 4K block or something so they aren't stored linearly. This means that a bad line
can cause the addressing to go completely wrong over the whole block so everything appears completely scrambled. So it could just be 1 bad
line causing the problems.
I had a look at the EEPROM problem first. After checking I realized what was wrong. Urgghh! I had used a 93C46 EEPROM and it should be a 93C45
EEPROM. They are sometimes compatible depending on how they are configured. In this case the 93C45 EEPROM is fixed at 64 bits x 16-bit and a 93C46
can be configured to either 128 bits x 8-bit or 64 bits x 16-bit when a specific pin is held high or low. That pin was not set because the 93C45
doesn't have that option so it was the wrong chip. After finding a 93C45 EEPROM in my parts bin and changing it the fault went away and the game booted
up fine. Of course that didn't fix my graphic problems.
I went around the graphics chips again even more carefully than last time and found a micro-hair of solder shorting 2 pins together. I
cleared that which improved the colors slightly. Then realizing there was nothing else to look at (all chips were mounted 100%), I double checked
the bottom side just in case there was another solder blob causing a short. Sure enough I found one. After clearing that it booted up and was 100% fixed!
Success at last!!
All cleaned up and ready to go. WOW! What an amazing transformation! :-)
So after reading all of this you're probably wondering who the butcher is, right? Well, normally I would not mention that because this was
sent for a useful purpose. But of course if you have been reading these pages for some time you will know I take great pleasure in giving
assholes who have screwed me over in the past their just desserts. This is no exception. The funny part is he can't even deny it. It's
documented ALL over the internet and a simple
google search will reveal the truth of who this horrendous butcher is. Hahahahah!!!
All I can say is if you value your undumped board DO NOT send it to him for dumping!
At least this ended well because it was sent to someone who could properly take care of it (i.e. me!) and now I can sell this board on my
Items For Sale page :-)
So now with all the excitement over I can use the working PCB to discover something useful for MAME..... I noticed recently a small change
to MAME relating to the volume chip used on these Data East boards. Unfortunately no one has documented exactly what chip is used for the
electronic volume control so the change is just guess work. The real PCB does not have a volume pot on it and volume is
adjusted in the test mode electronically. So I had a look, did a bit of research and identified the chip pretty quickly.
The Fighter's History PCB (and others like Night Slashers etc) use a Mitsubishi M5222FP Voltage Controlled Amplifier (VCA) in a tiny SOIC8
package which is used for the electronic volume control. You can see that in the above pic just near the group of larger electrolytic
capacitors. For those curious about the chip the datasheet is here.
22nd December 2016
OK so now that the cat has been let out of the bag on a public forum, I can mention that decapping of the chips on My Decapping Page has re-commenced on the 6th of December 2016.
You can check my
Decapping page for updates (look for green items with dates) and you can check the web site of 'CAPS0ff' (the guy doing the decapping)
The only question I have (and one I'm sure many others also have) is how many chips were recovered and which ones (if any) were lost? Update: All known lost chips marked on my Decapping Status Page
Big thanks to 'CAPS0ff' and I hope there are many more successful decaps and dumps in the future.
8th November 2016
When I dumped Crazy Dou Di Zhu II (Sealy 2006), at about the same time I also dumped an almost identical board for a game called Meng Hong Lou.
Luca added it to MAME recently. It has similar problems to the other game due to protection.
Here's a couple of screen shots....
2nd November 2016
With a bit of tweaking of the tool data and removal of the finishing pass (only roughing operations work) it will actually complete and the
G-Code is correct!
Here's a quick run through of a demo I created..... (note it takes about 30 seconds to load the floppy)
Here is a slightly more complex example that also works but the tool crashes through the part after roughing the concave section ;-)
So there are still some emulation issues even though it works. Hopefully all of those problems go away when the FPU emulation is fixed.
I forgot to add the floppy sounds in the first video so this 2nd video has the floppy loading sounds :-)
1st November 2016
Some more work has been done on the Fanuc System P Model G driver and now it mostly works. Unfortunately the previously mentioned buggy MAME
FPU emulation causes some issues and the more complex example shown in pic5 gets stuck when creating the machining paths and won't continue
past a certain point. I created a simpler example and falsely adjusted some of the tool data and basically just forced it to work. I have 30
years experience with FAPT and know how to make it do what I want even if it is physically impossible ;-)
The software is clearly having trouble calculating things correctly, but now it creates G-Code which is shown in the last pic :-)
Here are a few screens of the Color PG in action (shown without the clickable artwork for clarity).
Notice (in the last pic) the roughing (green lines) works but the finishing pass (yellow) goes off into space and is generating the same
coordinates over and over with E+07 at the end in an infinite loop hahaha!
Pretty amazing that it works though. I think back in 1982 the System P Model G was something like $20k! Most of you probably don't realize,
but that amount was easily made back in the first week of using it ;-P
27th October 2016
Over the last couple of weeks I've been working with a very talented guy (outside of the MAME Team) on the Fanuc System P Model G emulation.
He had previously, and with some success, emulated (privately) the Fanuc System 6A CNC controller (which is not in MAME). This was a
tremendous feat of reverse-engineering because the Fanuc CNC controllers use a lot of custom ICs and very locked-up specialized technology.
He kindly helped out with the PG emulation in MAME and it is now mostly working. Unfortunately there are issues caused by missing/incomplete
x87 FPU emulation which appears to be completely unused in MAME. The PG uses an 8087 and MAME has no examples of it's use since it's an
optional chip in all PCs and is not actually used in any driver. It may get fixed eventually, or this very talented new guy may figure it
out along with the remaining issues.
Here are a few screens of the emulation in action using artwork I created with pics taken of my real PG System....
There are many floppy disks and manuals that were originally made to go with this yellow box of tricks. I happen to have a few of them here
and they have been archived for use with the emulation.....
We need help to locate any of the remaining floppy softwares that may be out there in some dark engineering workshop or sitting on
a shelf in an office somewhere, unused for the last 25 years.
If you have worked in Engineering in a CNC-related job and have access to any of these Fanuc System P floppy disks or know someone who does,
please contact me so we can get them dumped and archived for future use.
I have also been working on a battery-damaged Amiga 3000 that a friend asked me to look at. This is possibly the worst battery damage I have
seen so far. After stripping, cleaning, re-assembling with new parts/new sockets and patching dozens of tracks (most are not visible because
they are under ICs and patched directly on the board using 0.15mm wire) it was mostly working but not stable. Investigation revealed one of
the legs on the Agnus chip has become very weak and was almost falling off. This was caused by the previous owner who had tried to do some
butcher repairs and broke the corner off the Agnus socket in the process (seen in the first picture), and also damaged the legs on the Agnus
chip on that same corner. Initially I bent them back into place but once chip legs are bent they weaken and eventually break off. When I
noticed the bad connection on one pin I removed the Agnus from the socket and casually touched that pin with a finger and it fell off! So I
had to grind away the plastic to get to the leg and solder a wire in place. That appeared to fix it for a while but it still has some
issues. Let this be a lesson to all of you Amiga fans out there.... if you own an Amiga and you have not touched it for years, go find it
now, open it up and remove the internal barrel battery before it's too late!
Here's a few pics of the repair....
25th October 2016
Recently I completed the dump of Crazy Dou Di Zhu II (Sealy 2006) and Luca has done some work on it in MAME.
It's now starting to do something....
and for comparison, here's a pic of the title screen from the PCB....
10th October 2016
Regarding the Quiz Punch news below, it looks like my MCU dump was ok. Luca did his usual magic and it's partly working in MAME now.
24th September 2016
I'm currently in the middle of re-organising all the PCBs and stacking them on a metal shelf rack so things can be found quickly. Here's a
quick Work In Progress pic..... I'm almost finished :-)
The Items For Sale list has also been updated, including adding a few boards that were previously at
unknown locations or unlisted.
While going through the boxes I found a couple of boards that were not dumped so I dumped them. One was a Poker/Casino game by 'Status
Games' and the other was by 'Kramer Mfg' and was dumped but the existing dump is incomplete and missing the color PROM.
I also checked one PCB that was not labelled, and it identified as 'Quiz Punch'.
I dumped it years ago but checking in MAME I saw that there were missing ROMs. That's because the game has an epoxy block on it so I decided to open
it. It was actually really easy to open with just a flat bladed screwdriver. After cracking the sides off the plastic case, the inside was
revealed and the PCB inside it was just glued on. I put the screwdriver between one of the chips and the top of the plastic epoxy block
cover, twisted the screwdriver and the whole thing just popped off in one piece :-D
The pics show the parts inside. A Z80B at 4MHz, 4 logic chips, a 68705P5 microcontroller and an unknown DIP8 chip.
Notice the writing from the Z80 has stuck to the glue inside the epoxy block cover haha!
I removed the 68705 and read it and something came out so maybe the dump is OK. Not sure, as subsequent reads gave nothing.
Now onto the DIP8 chip.... I pulled it off and on the bottom side of the chip it has the part number and pin-1 notch! So this chip was
upside-down. In this configuration the chip is non-standard and can't be read as-is. I bent the legs out straight and soldered it into a
larger socket (also fixing the broken leg at the same time) then just read it as a 93C46 EEPROM. The dump was good!
4th September 2016
A few months ago I was given a Merit Megatouch Force 2006.5 unit by a local friend. It was told it wasn't working so it sat outside in my
garage for several months. I decided to have a look at it yesterday. The unit would not boot up. The first issue was a dead motherboard
battery. After changing it for a new one and resetting the BIOS defaults and tweaking them, it booted up but gave some error about the
motherboard model not being correct. I went back into the BIOS and set the factory defaults and then it got past that error and booted into
the game. The touchscreen didn't work. I went to the calibration setting screen and tried to recalibrate it but the screen did not register
presses. Inside there was a rats nest of hacky wiring and several wires were chopped off and tied up. Other wires were dangling everywhere.
A small AMP board was just sitting on the frame and had some insulation tape wrapped around it to stop it arcing to the metal. Looks like
some rough operator really went to town on this unit and made a real mess of it. I wouldn't trust that guy to pull out weeds correctly!
I pulled it apart completely and then I could see what was supposed to be connected to what and while I had it apart I documented the
hardware. The touchscreen issue was caused by some dangling wires that had caught on something and pulled out a connector on the touchscreen
controller breaking a solder connection on it. After re-soldering it, cleaning it out, tidying up the wires and re-joining the chopped ones
(basically putting everything back to normal as it should be) I went back into the calibration setting screen, did the screen calibration
and then it kind of worked but only on some parts of the screen and it only registered presses occasionally. That problem was solved by re-doing
the calibration again, but this time when pressing the opposite corners as instructed, I held my finger there for 2 seconds. That is
actually documented in the manual ;-) After that it all worked properly :-D
Having this all working now, I decided to do some research about these units as this was the first time I had seen a Megatouch. The info out
there says this has a security module on the I/O board. The I/O board is there but there's no security module!! I have a couple of pics
below showing a comparison of the I/O boards. Looking closer, it turns out this box is *nothing* like a genuine Megatouch Force
unit. The whole thing appears to be a copy. I have some suspicions about 'who' did this, but I won't mention the company here. Let's just say they
are located on the East side of Australia in Melbourne and they were fined about $500K a few years ago for pirating some other stuff (by
ICE, if I recall correctly), so no doubt it's the same guy up to his old tricks again.
Anyway, the security has been hacked out so it works as-is without the special security dongle. That's a bonus for us because that means it
should make it easier to add to MAME because essentially it's just a PC running Linux. The extra PLCC chip on the I/O
board may be a problem but maybe not. I suppose we will find out when it's added to MAME.
Here's some pics of the unit....
I will probably sell this eventually, I have very little interest in Megatouch games. If you are interested to buy the whole unit complete and working, contact me.
21st August 2016 Luca has been working on some of the latest arrivals shown below. Here's the first one.....
It's a rare Namco game called "Star Audition"
15th July 2016 THE mother-load arrived.
Note these are all original PCBs and none are currently dumped.
All items will eventually be listed on my Items For Sale page.
p.s. Hi Micko
p.s. Bye Micko
19th June 2016
Today I received a rare game called 'Number Crash'. The game now works in MAME :-)
2 bad ROMs were redumped and some dips/inputs were added but it was not playable. I fixed the remaining inputs and dip switches and now it's playable.
Seems the MAME guys were too lazy to do it and it was pretty easy....
the apathy has definitely set in as MAME slowly dies. Anyway, after fixing all of that it's now playable. The changes were added to the source by Luca.
Thanks to Kuro-san for the PCB donation
3rd June 2016
This Konami System 573 3 player Hyper Bishi Bashi Champ repair job arrived the other day. It turned out to be an undumped Korean KAA version so I dumped it and it was added to MAME today.
14th May 2016 (6)
I decided to clean out the Tekken Tag Tournament 2 Unlimited box today so here's a few pics of the inside of Namco System 369 and a few pics of the
game screens. Basically System 369 is the same as System 357 but is using a slim PS3 mainboard and 2.5" HDD. The cooling method has been re-designed but
unfortunately they are still unreliable because it's still just a PS3. The game should have been called 'Limited', not 'Unlimited'. The system is
hobbled and plays only 1000 games if not connected to the Namco network then requires payment to Namco to keep it working. Worse, that service is no
longer available so when you get to your credit limit you'll have to get one of the cracked HDD's with that limit removed if you want to keep using it.
Fortunately I have one of those too ;-)
12th May 2016 (5)
Today I received a couple more dead/suicided CPS III carts to do the Darksoft mod on. One of them looks very dodgy. I dumped the ROM and it's unknown so it may be a
bootleg conversion of some kind.
The first thing I noticed was the label is not the same color as an original and appears to have been printed on a color laser printer. The original is on the right,
copy on the left....
Here's a zoom of the copied label.... you can see horizontal lines through the image. Hmmmmmm.....
The second thing I noticed was the screws holding the cart together were covered in hot-melt glue, which of course is not on genuine carts. Note the
photo below was taken after the conversion was done and I've removed the glue but you can still see traces of it, including some on top of the sticker.
The third thing I noticed is there's one of those 'Warranty Void If Removed' stickers on the side which is not present on genuine CPS III carts and it's identical to the sticker covering
the screws holes on Capcom CPS II A/B boards.
So the hackers put a genuine Capcom CPS II security sticker on the CPS III cart to make it look genuine hahaha!!!
Note the label on the back of the cart is also a copy. All these imperfections point to a bootleg conversion. Either way this cart was not dumped so
now we have another alternative ROM for one of the CPS III games :-)
29th April 2016 (4)
I noticed a few days ago that a couple of ROMs from the Silent Scope 2 network PCB were recently flagged as bad and therefore need to be redumped.
Guess what I just got hold of ;-)
26th April 2016
A lot of people have inquired recently about whether I do repairs. The answer is yes.
As an example, I've just finished a huge repair job.... lots and lots of Sega Model 2 Daytona USA sound PCBs. These took around 2 months to fix, working on them now and then as
time permitted, but now every one of them is working perfectly. One of them was covered in some kind of sandy or saw-dust crap and looked like it had been under water.
Another was covered in half-dry sticky Coke for about 10 years and was deemed scrap back then. Many were rusted beyond the grasp of mere mortal repair people.
After some Guru-magic they all look perfect and are now all working and rock-solid and should last many years :-D
I also have several of these Daytona USA sound PCBs for sale.
If you have any PCBs you need repaired, contact me.
21st April 2016 (3)
Another repair job arrived today. This time we have a couple of Capcom CPS III carts that are in need of a nice Darksoft BIOS modification because
Here's a few pics of the repair job. If you have any Capcom CPS III carts that have suicided, or you just want to be able to play any of the CPS III
games and you would like to have the cart(s) converted, contact me for more info.
Note, I have a number of CPS3 carts for sale, both cased and uncased. All of them are modified with the Darksoft CPS3 multi-game BIOS and all work
fine without the battery so should last almost forever :-)
While converting these, I dumped the ROM in each cart and one of them was not in MAME, so I found an undumped version :-)
If you have any CPS3 carts you need repaired/ressurected, contact me.
10th April 2016
I've been playing with the CPC6128 emulation in MAME again and by pure luck I figured out how to run ROMs that are plugged in via the ROM
Expansion so I'll let everyone know here, since there doesn't seem to be any info that I could find about it or anyone who knows.... at
least nothing I could find in my limited searches.
Here's how it went down....
After much research about the CPC6128 over a couple of days and finding nothing, I decided to re-check what I already knew as a start.
On the CPCWiki it says how to load the ROMs but nothing about running them. Ok, so let's get it loaded..... mame cpc6128 -exp rom -rom1 roms\cpc\protext.rom
This starts the CPC6128 emulation and configures the CPC with the expansion 'ROM' slot device. The ROM slot device has 8 slots for ROMs. It then
loads ROM1 into that slot. In my case the ROM I want to load is called 'PROTEXT.ROM'. Using the command line above this is the result....
So far so good, but no obvious way to 'run' it????
At least not for a Commodore boy like me. I'm sure all you Amstrad guys are saying 'WTF it's EASY!!' ;-)
So during my research I came across a manual for a DIY ROM Expansion board by Maplin.
I got the manual and it gives some info about testing the board and says to type |HELP to get the menu. The Maplin board seems to be
using some kind of test ROM, but of course with my ROM that didn't work either. My ROM is called 'PROTEXT.ROM' so just off the top of my
head I decided to type |PROTEXT and this was the result....
Oh Oh! success! The command can even be shortened to just |p and it still works. So I decided to replace the ROM with a game rom
(TAPPER.ROM). I loaded the ROM into the expansion like this.... mame cpc6128 -exp rom -rom1 roms\cpc\tapper.rom
Then I reset the computer. The usual start screen appeared with no message. I typed |TAPPER and guess what...
So *that's* how you run the ROMs plugged in via the ROM Expansion board on a CPC6128. Amazing ;-)
The ROM Expansion board is actually a pretty nice thing because it lets you have 8 ROMs plugged in and always accessible via a simple command.
That's all fairly old technology though. I would think by now there's a flashROM based board that lets you play the disks/tapes/ROMs directly from a SD card or USB stick, like most of the other old computers and consoles have now.
Anyway, now you know.
Looks like it's time to re-visit the CPCWiki linked below and try some of the other ROMs that are available :-)
Of course all the above is only academic. If you want usable/playable CPC6128 emulation use another dedicated emulator because MAME's
emulation is too slow unless you have an i7.
BTW, I don't have any use for this CPC6128 which is a donation I can keep (other than stripping out the sixteen 64kx1 DRAMs for future Commodore 64 repairs hehe!) so if you are interested to buy it and help generate some funds to go towards other things,
Now for something funny....
News about my post below was posted on mameworld forums by Enrique (yeah, the guy who spent considerable time, effort and money to send this
CPC6128 to be dumped). He told me some fucking bastard (his words) on MW (probably Shitdogg) deleted the post and he's not happy about that!
Oh yeah that's how to treat a donator, delete his news post about this new dump for MAME and ban the poor guy.
WOW! You're supposed to be supporting MAME, not turning people away, you shortsighted asshole. You are supposed to be enthusiastic about
people who provide things to dump so that your image improves and then more things will come your way. You're not supposed to whinge and
whine about doing dumping work for MAME, make up lots of excuses to get out of doing the work and say you hate it and then say you don't offer any
guarantees it will work afterwards (classic example here). Geez what a loser.
Deleting posts and banning those people only causes grief and makes the whole of the DU look bad (well, worse than it is now, since Shitdogg
is their so-called 'leader' and also a forum admin so anything stupid that he does has a domino effect).
On second thoughts, keep going! Eventually no one will bother with the DU and I'll still be going strong! Hahahahah! This act of
contempt and disrespect for donators only strenghthens what I've always said.... that Shitdogg is out of control, is only bringing a bad
image to the DU and needs to be replaced immediately with someone who knows how to handle responsibility and lead a team the right way. Need
more proof? Check my old post here for a refresher.
Anyway, this is hilarious! To any future donator, don't bother with anyone else when you have something that needs to be dumped, just come
directly to me for proper service and care. I'll look after you.... the thousands of news posts on this site prove that :-)
Based on the rate of things arriving, people can see exactly where the knowledge and experience is.... it's right here. You can already see
things here are improving even more than usual now that I have loads of free time to deal with new dumping tasks and *lots* of items have arrived over the
last few months. More updates on that soon, I'm just waiting on the latest few items to be finalized :-D
The bottom line is if you want something dumped properly and working afterwards, send it to me.
7th April 2016 (2)
Another unusual item rolled up today..... an Amstrad CPC6128. The Spanish version. Thanks to Enrique for sending it out.
Here's some pics....
There is a fairly large archive of CPC ROMs (etc) at http://www.cpcwiki.eu/index.php/ROM_List
However a lot of the OS ROMs are non-standard as per real life ROMs found on the CPC6128 hardware and don't work in MAME's CPC6128
emulation, including the Spanish version..... which is why the CPC6128 was sent to me for a re-dump :-)
The existing dump does not work in MAME and is considered a bad dump by MAME's criteria. They may or may not work in other emulators but
that is not my problem or my concern. My job here is to dump it correctly so it works in MAME.
The BASIC and BIOS are combined into one 32k 'OS' ROM and the Floppy OS is in a 16k ROM.
You can see those two ROMs in the pic above, located just below the Z80 CPU.
The Floppy OS ROM is marked 'AMSTRAD 40015' at IC204 and the OS ROM is marked 'AMSTRAD 40038' at IC103.
The Floppy OS ROM is common to all versions of the CPC6128 and under the ROM, printed on the PCB is '40015'.
Under the OS ROM printed on the PCB it says '40025' so I'm guessing the regular common English version would be marked with that number too.
The existing dump of the Spanish OS ROM is 16k, therefore incomplete and thus bad. Again, this is as far as MAME is concerned.
The actual ROM is a 23256 mask ROM, but this particular OS ROM used in the CPC6128 is not 100% compatible with a 27256 and can't be read using that type.
Because the ROMs are slightly non-standard it requires a little trick to get a good dump out of it.
I'm told the most important key on a Spanish keyboard is the enye (ñ), which is located next to the L key.
As you can see from the screen shot below (running in MAME), it is there and emulation is working just fine using my re-dumped ROMs :-)
The only other difference I see is the top title has a (s3) at the end, whereas the existing English version says (v3).
As usual, with many early ROM dumps they were very poorly documented, or not at all and the file names are a big mess.
This re-dump fixes that problem too :-)
If you want to try the CPC6128 emulation (or in fact any old computer emulation) you'll need to know a few simple commands.
Unfortunately MAME's UI is quite poorly designed and has no built in or external simple 'how to use' help file system via
simple text files (like it *should* have), so I'll list a few simple CPC6128 commands here for loading the various media types.
Note you should be at a command prompt and in your MAME directory (i.e. C:\MAME or where-ever your MAME.EXE is located). If not CD to the correct directory.
You also need the CPC6128 ROMs and they should be in your MAME/ROMS dir.
Loading from a cassette tape:
Get hold of a CPC6128 .cdt cassette file from the net (use google to search)
For this example the file I have is called 'xevious.cdt' and is located in C:\MAME\ROMS\CPC\
At the command prompt type mame cpc6128 -cass roms/cpc/xevious.cdt
The emulation will start and the Ready prompt will show on screen
Type |TAPE (| is shifted @ on the CPC6128 or shifted [ on a PC keyboard)
then type RUN "XEVIOUS" then press the ENTER key. Or you can just type RUN" and press ENTER
A prompt will ask you to press PLAY on the tape drive then to press any key.
Press scroll lock to get PC keyboard partial control and press F2 then any key. At the top left corner a tape counter will show and then you must
wait for the tape to load. You can press the PC's INSERT key to speed it up.
When it finishes loading, the game will automatically start.
Note I found using load i.e. LOAD "XEVIOUS" didn't work... it loaded but the game didn't start and there was no way to make it go. YMMV.
If you want to know what files are on the tape, type CAT and press the ENTER key. Then press PLAY and wait for the files to be listed.
Remember to rewind the tape using the UI menu (scroll lock / TAB / tape control) before issuing commands if you have previously played the tape
Loading from a disk:
Get hold of a CPC6128 .dsk file from the net (use google to search)
For this example the file I have is called 'operwolf.dsk' and is located in C:\MAME\ROMS\CPC\
At the command prompt type mame cpc6128 -flop1 roms/cpc/operwolf.dsk
The emulation will start and the Ready prompt will show on screen
Type LOAD "OPWOLF" then press the ENTER key
The file will load and then display the Ready prompt. Type RUN and press the ENTER key to start the game
Alternatively you can type RUN "OPWOLF" and the game will load and automatically run
Note I found using load would sometimes work and sometimes not, depending on the game. For example LOAD "OPWOLF" works but not for a file
I have called 'outruneu.dsk'.
In this case I had to type RUN "OUTRUNEU" to get it to load. Other times it would start to load then say 'Out Of Memory'. Using RUN instead of LOAD fixed most
of the loading issues I had with a number of different programs I tried. But note using RUN by itself like the tape example above (i.e. RUN") doesn't work for disks.
If you want to know what files are on the loaded disk, type CAT and press the ENTER key (or |DIR). Then the files will be listed.
The manual said most commercial disks could be loaded and run by typing RUN "DISC" (aka like LOAD"*",8,1 on the C64) but it didn't work for me.
There's also ROMs (.bin) available for the CPC6128 for some games and other programs that can be loaded by adding an expansion ROM BOX via MAME's
command line or UI menus, but I couldn't get the actual ROMs to 'run' either. They would load and display a small text message on screen at boot-up,
but I didn't see any way to 'run' it, and there's no mention of running ROM carts in the manual. As usual information is randomly spread out wide
and far and MAME is no help at all so some more net research is needed :-/
Anyway, that's the basics of loading and running tape and disk software on the CPC6128 via MAME.
You might be thinking all of the command line typing is bullshit and so 80's, but actually it's the fastest and easiest way to get things
going in MAME with computer emulation. Not because it's faster to type when you know what you want, but because the MAME UI sucks. Even the
latest incarnation of it. Sure most of it could be done via the built-in UI now as-is providing you had time to go through the menus and set
it up. The bottom line is it still has a LONG way to go before it is as professional and slick as some of the other UI's in system-specific
emulators like for example, the Enterprise EP128EMU. But even typing things has it's issues because of the extreme lack of info in MAME
regarding what to type. I'm talking about MAME running computers (etc) of course. We all know MAME does arcade emulation pretty well
(although you need an i7 to make proper use of it) and the UI is not all that important. But for running computers it is. MAME was king with
arcade games but now that it's merged with MESS it's taken a big step backwards.
In the UI, things like the hardware add-on menus are cumbersome and unorganised. Compare that with the EP128EMU Emulator
to see what a slick emulation menu system should look like. BTW, this emulator also has perfect emulation of the CPC6128 and ZX Spectrum.
Another example that should have been done years ago is internal ROM auditing. For years that code has been hidden from the release because
MAMEDEV didn't want you to know what was available and wanted to shield you from becoming a pokerom. You could just use CLRMAME anyway so it
was pointless. Haha! The current UI makes it worse because there's a filter to show what is available but no way to do an audit, so the
'Available' filter shows more items than are actually available. Personally I'm not sure how an 'Available' filter can even work without
doing an internal audit first. I have only a handful of ROMs on this PC, but it shows dozens of systems I don't have (for example the
Famicom, and I don't even have the BIOS/boot ROMs on this PC!), and when I click on it the list changes to a long list of carts and I have
none of those either. Clicking on any one of those items brings up a message stating the file can't be found. Erm.... duhhhhh! I know that I
don't have any of them and they should not even be listed with the 'Available' filter activated.
Here's a pic showing what comes up when there are NO ROMs at all....
Clearly the filters need some work so that the emulation looks for the BIOS/bootROM *first* and if there's no BIOS then don't show the
software lists of carts etc.
The whole idea of an 'Available' filter is to only show what's **actually available** :-/
Yet another example of sloppiness, when using the menu to select a file to load in (such as a tape or disk image) the UI shows [DIR] for zip files.
So it looks like this....
LOL! Last time I checked a zip file was not a dir.
Another example, in the UI there's a 'How To' section on the right side when the < or > is clicked, but that 'How To' information is no
where to be found. Obviously the How-To for arcade games is the cab instructions which is an image and available as the 'Extra Files' from
various sites on the net. But for computers, this needs to be linked to an external help file to show the user how to get started. It's
exactly the kind of thing that should have been designed with an extra 10 minutes of thinking and checked properly. They don't build cars
with accessories that have missing pieces, everything is present and just works. I've only used this new UI version of MAME for an hour and
already I found several problems. And MAME has been going for how long? ~18 years, and still not user-friendly and with a slick interface.
Hopefully one day the myopic powers at the top will wise up, move into the 21st century and make MAME more user friendly. Hopefully they
will take a good long hard look at the other emulators like EP128EMU and take some ideas from it.
Hopefully one day they will actually use the full power of PCs to make MAME run at full speed instead of crawl along like a snail.
Hopefully one day they will add some kind of external linking to simple system-specific help text files to get people started and include
those with MAME. Just the simple stuff like how to load the media and get it booted. Then maybe some external group will make a simple text
help file for all of the computer systems supported in MAME, instantly improving MAME's image ten-fold. Maybe a group already exists who
have created all of that but I didn't find it with a quick search. If it does exist now it should be included with MAME by default. At the
very least the help files should be available for download together with MAME on the same site. The whole thing should be organised on a
wiki and a program used to capture the relevant files and auto-make text files of the latest wiki info. It's not rocket science people.
There could even be a button in the UI to download the latest set of help files straight off the hosting server without having to search
100's or 1000's of sites for 'MAME Extra' files. Now that MAME includes computers too, the whole process to make it more user-friendly
requires some serious thinking and planning. Thinking and planning that has been lacking so far. For a so-called 'documentation
project' this big and this old it is seriously lacking any kind of real-world user documentation that would make it more usable and
Unfortunately certain people think I'm only a ROM Dumper who knows nothing about design or programming, even though in reality I worked as a
CNC/PLC Programmer at the top of my field for 30 years and designed and manufactured many thousands of things over the years including
secret prototypes for billion-dollar corporations. But sadly due to me being 'just a ROM Dumper', the apathy and stubbornness of certain
devs, and where MAME is now, stuck in a rut where most of the work being done is mostly pointless re-factoring (just check the github
commit history online for what's going on... not a lot of useful stuff there), most of what I've suggested here will be written off and
never be done.... thus MAME will stay in the dark ages forever and never really achieve mainstream exposure or the highest status for
emulated computers and consoles. Maybe now that MAME is really open-source they will grab some code from some of the other better open-source
GPL'd emulators and improve things. Or maybe certain devs' pessimistic attitudes will just push the project back further and into
self-destruction. I suspect the latter. Only time will tell.
The moral of this story is simple..... when running computer emulation in MAME, skip the UI and just type in the bullshit at the command prompt ;-)
Anyway, regarding the above simple explanation of how to use the CPC6128, I hope it was useful to someone who might want to try the
emulation. Until things improve in MAME, if you want to know more the full CPC6128 user manual is available at the
5th April 2016 (1)
Just finished another repair job, this time to a couple of Sega Afterburner II PCBs.
One had messed-up colors, that was just a bad color RAM. Here's some pics of the repair.
After changing the bad RAM it looked like the problem was all fixed. Or was it?
Look closely and you can see some tiny dots around the plane wings. I checked all of the crappy Fujitsu mask ROMs and they were actually all ok. Hmmm. I wonder...
I'll just check those 3 EPROMs that were changed by someone else.....
They ended up bad. All 3 of them! WOW!
Changing the 3 bad EPROMs fixed the graphics problem.
After talking with the owner I suggested he should get rid of all of the Fujitsu mask ROMs and replace them with EPROMs so it will last longer because
this board is running in a cab. He agreed, so I bought some equivalent EPROMs (27C1000 to replace 831000 28 pin masks) and programmed the
whole lot. Here's a pic of the finished job.
The other Afterburner worked fine so the fault is with the monitor in the cabinet. I checked the ROMs on this version and it is a moving cab
DX version which is currently not dumped. So that's another new dump found :-)
23rd March 2016
With the large amount of spare time I have now, in between sleeping a lot to catch up on 30 years of lost sleep, and going out with friends for lunch or a cappuccino,
I occasionally have time to look at repair jobs.
An interesting and unusual repair job came in last week.
It's a Neogeo AES console.
These seem to be pretty rare nowadays and expensive *if* you can find one for sale.
This one was initially dead. It had developed a bad connection between a RAM and the CPU due to some minor corrosion because it was stored poorly
for a few years outside in a shed. After quickly finding the problem I connected it temporarily with a couple of micro jumper clips and up it came, working
fine. The bad track went under both RAMs and only on the top side of the PCB so I patched the track as neatly as possible. Now it's working just fine :-)
Here's some pics of the repair....
The owner also wanted a Uni BIOS fitted so I did that too.
If you need something repaired and can't find anyone to look at it, or as in this case, no one has any clue what it is or how to fix it, maybe I can
help you. I will look at anything including consoles, old computers (such as Amiga, Commodore 64, Atari, Mac etc etc) and arcade PCBs,
plus anything else electronic that happens to be out there.
To give you an example, a while ago I fitted a region mod chip to a Blueray player for a friend.
However please note I don't do repairs for free, otherwise I'd be inundated with repair requests and I'd have no time for lunch and the cappuccinos!
But don't worry, my repair fees are quite reasonable and if it can't be repaired there's no charge..... you just pay return postage if you want it back
or nothing if you don't want it back. Drop me an email if you have something that needs to be repaired :-)