The Space Invaders TS-80 'Bootleg' Project README File ====================================================== v1.0.0 In order to play Space Invaders on the TRS-80 (emulator or actual machine), you'll need a copy of the original arcade ROM image. The ROM image is copyrighted and not mine to give away, so please do not ask me for it. Unless this is your first time on the internet, you should be able to find it within a couple of minutes! You'll need the romset that MAME identifies as 'INVADERS'. Name Size Checksum invaders.h 2048 CRC(734f5ad8) SHA1(ff6200af4c9110d8181249cbcef1a8a40fa40b7f) invaders.g 2048 CRC(6bfaca4a) SHA1(16f48649b531bdef8c2d1446c429b5f414524350) invaders.f 2048 CRC(0ccead96) SHA1(537aef03468f63c5b9e11dd61e253f7ae17d9743) invaders.e 2048 CRC(14e538b0) SHA1(1d6ca0c99f9df71e2990b610deb9d7da0125e2d8) The ROM image files need to be concatenated together as follows: cat invaders.h invaders.g invaders.f invaders.e >invaders.rom (on linux) copy /b invaders.h+invaders.g+invaders.f+invaders.e invaders.rom (on windows) Virtual Disk Image ================== The image is a bootable (LDOS) virtual disk image with the SI/CMD executable. This executable reads the ROM image from a disk file named 'INVADERS/ROM'. After you've created the ROM image above, simply import the file into xtrs using the IMPORT/CMD command file included on the image. Execute SI/CMD to play the game. Intel Hex Image and Serial Booting ================================== The SILDR.BIN file is binary image that may be concatenated with the invaders ROM image and downloaded to the Model 4P via the serial boot ROM procedure. First, concatenate SILDR.BIN to the end of the ROM image: cat invaders.rom sildr.bin >sitrs.bin (on linux) copy /b invaders.rom+sildr.bin sitrs.bin (on Windows) Next, convert the binary image to intel hex format, using the bin2hex package I've provided: bin2hex -b6000 -t8000 sitrs.bin >sitrs.hex This image may now be downloaded from a (Win32) PC to the Model 4P using SBOOT4T. Playing Space Invaders on the TRS-80 ==================================== Standard MAME keys apply (more-or-less). Insert Coin 5 1P Start 1 2P Start 2 Joystick Left Left-Arrow Joystick Right Right-Arrow Fire Space Bar History ------- v1.0.0 ------ Initial release. I've spent the last 2 days optimising the graphics peformance as far as I think possible. I've also disabled interrupts around the TRS-80 graphics routines to minimise glitches, but one or two occasional glitches remain - there's a small glitch during attract mode off the RHS of the visible area of the display. This area is not normally visible on the real arcade machine. Not worth the extra CPU cycles to fix. I don't think I can do much more with the graphics, so this is it! Runs at 50% on unpatched xtrs and real Model 4 due to the fact that the RTC interrupt is still being used for the 120Hz interrupts. As far as I can tell in xtrs, this version shuold run with 120Hz interrupts! TBD: next release will run off external interrupt. Preview 2 --------- Version that runs on an unpatched version of xtrs. Change #define TIMER_HZ_4 60 -> 120 to run at 100%. Screen yet to be rotated. Preview ------- Version that runs on a patched xtrs only. Screen yet to be rotated. Feedback welcome!