The Bendix G-15 General Purpose Digital Computer System

Documentation

What we have, What else is available, and What we don't have

Last updated: 3 July 2010: David Green

What we have

We have a variety of documents and manuals. The programming, operating and technical manuals are listed below. Sundry conference papers, newsletters, etc. are not listed

[ 1]. The Bendix G-15 General Purpose Digital Computer System, July 1961. G-15 Technical Bulletin - Equipment Series. publ. Bendix Computer Division of The Bendix Corporation. (Introductory brochure).

[ 2]. "Bits of Meaning" (1.37Mb) Publication APG-12591-0761. publ. Bendix Computer Division of The Bendix Corporation. (Introductory programming manual).

[ 3]. "Programming for the G-15" publ. Bendix Computer Division of The Bendix Corporation. APR-01601-1, revised July1961. This manual is quite long (214 pages) so it is stored as four parts to keep the files to a reasonable size: Pages 1-65 (2.9 Mb), Pages 66-117 (2.6 Mb), Pages 118-155 (2.2 Mb), Pages 156-214 (2.2 Mb).

[ 4]. "Programming Manual", Control Data G-15 Computer, 1964 publ Control Data Corporation. This is a reprint of "Programming for the G-15", APR-01601-1, revision July1961

[ 5]. "G15D Programmer's Reference Manual", (no date) (3.93Mb) publ. Bendix Computer Division of The Bendix Corporation.

[ 6]. "G-15D Programs and Subroutines". No date. publ. Bendix Computer Division of The Bendix Aviation Corporation.

Contents:
   Section I 
      Program Preparation Routine (PPR-D1)......................#1000
   Section II
      Input - Output.(Binary to Decimal; Decimal to Binary).....#1101
      Sine, Cosine, Arcsine, Square root, Arccosine.............#1202
      Rectangular to Polar Coordinates..........................#1203
      Linear Interpolation......................................#1204
      Complex Multiplication and Division.......................#1205
      x to the mth..............................................#1206
      Log x.....................................................#1207
      e to the x ...............................................#1208
   Section III
      Sine (INTERCOM)

[ 7]. Coding Manual for the Bendix G-15, April 1961 Publication APG-01571-3, formerly T3-3. publ. Bendix Computer Division of The Bendix Corporation. (24 pages) The file is 3.1Mb so you may prefer to refer first to the Contents Page

[ 8]. Operating Manual for the Bendix G-15, July 1959 publ. Bendix Computer Division of The Bendix Corporation. Publication Manual No. T 8-2. (3.4 Mb).

[ 9]. G-15 Technical Manual Revision #1. Part 1: Simplified Drawings. No date. 62 pages publ. Bendix Computer Division of The Bendix Corporation. (3.0 Mb) An index of the prints contained in the manual can be seen here. (64kb)

[10]. G-15 Technical Manual Revision #1. Part 2: Theory of Operations. No date. 108 pages publ. Bendix Computer Division of The Bendix Corporation. This is reproduced here in two halves, to keep the file sizes down: Sections A, B and C (2.86Mb) and Sections D thru H (3.16Mb).

[11]. G-15 Technical Manual (Revision ?). Part 3: Appendix - Test Routines 1 & 2 etc. No date. This copy of the 48 pages covering the operating instructions and source code for the test routines was kindly scanned for us by Joel Ewing from his copy of the manual. The Appendix is missing from our original manual. (1.1 Mb).

[12]. Detailed prints of the G-15 circuits. These prints were too large for my scanner, so I scanned them in two halves - a left part and a right part. For each print the two halves have been saved in a separate zip file as follows:

  • 3D230: Schematic of Photo Tape Reader 15 December 1955
  • 3D281: Schematic of Power Supply 14 May 1956
  • 3D282: Schematic of Typewriter 8 June 1956
  • 3D283: Schematic of Clock 8 June 1956
  • 3D293: Schematic - Inverting Gate & Early Bus, G15D 19 August 1956
  • 3D296: Schematic - Memory Lines 0,1,2,3,4,5 & 6. G15D 17 August 1956
  • 3D297: Schematic - Memory Lines 7 thru 18. G15D 12 August 1956
  • 3D298: Schematic - Registers M20, M21 & M22. G15D 17 August 1956
  • 3D588: Schematic - Input Output 1 & 2. G15D 17 March 1959
  • 3D589: Schematic - Input Output 3 & 4. G15D 17 March 1959
  • 3D590: Schematic - Input Output 5 & 6. G15D 18 March 1959
  • 3D591: Schematic - Input Output 8. G15D 17 March 1959
  • 3D592: Schematic - Input Output 11 & Register MZ. G15D 17 March 1959
  • 3D593: Schematic - Control Gate 1 & 2. G15D 17 March 1959
  • 3D594: Schematic - Control Switch. G15D 17 March 1959
  • 3D595: Schematic - Product Gates. G15D 17 March 1959
  • 3D596: Schematic - Timing Gate & Accumulator Gate. G15D 17 March 1959
  • 3D597: Schematic - Magnetic Tape Control. G15D 17 March 1959
  • 3D598: Schematic - Location Diagram - Package. G15D 17 March 1959
  • 3D872C: Schematic - MTA 2. 13 October 1960

    [13]. Errata sheets for G-15D Technical Manual Revision #1. 9 june 1961 (98kb).

    [14]. G-15 Supplementary Drawings: Alphanumeric Input/Output System. (1.25 Mb) Edition AET-05615, May 1961. publ. Bendix Computer Division of The Bendix Corporation.

    Drawings intended to supplement those in the G15D TECHNICAL MANUAL - REVISION #1, which document/s the NUMERIC G15's. The drawings cover the ALPHANUMERIC INPUT/OUTPUT SYSTEM and the associated TYPEWRITERS (AT-1, AT-2) and COUPLERS (NC-1, ANC-1, ANC-2). Also included are three drawings (72-74) covering new circuits not necessarily associated with the INPUT/OUTPUT system. A summary of the G15 logic changes is provided on drawing 66 in equation form.

    INDEX OF DRAWINGS
      65.  INTRODUCTION
      66.  EQUATIONS
      67.  AN IN/OUT CONTROL (OC's)
      68.  AN INPUT block
      69.  AN SLOW OUT block
      70.  THE OUTPUT LINK
      71.  AN-RELAY CHASSIS
      72.  ACCESSORY CONTROL #1
      73.  ACCESSORY CONTROL #2
      74.  CF3 PACKAGE
      75.  NC-1:  NUM. COUPLER
      76.  ANC-1:  CONTROL CIRCUITS
      77.  ANC-1:  DECODER (simplified)
      78.  ANC-1:  DECODER (detailed)
      79.     "       "        "
      80.  ANC-1:  ENCODER (detailed)
      81.     "       "        "
      82.  ANC-2:  DECODER
      83.  ANC-2:  RELAY CONTROL
      84.  ANC-2:  ENCODER
      85.  ANC-2:  G15 CONTROL
      86.  IN/OUT WRITER (AT-1/AT-2)
      87.     "       "        "
      88.  ANC-1:  AN TYPE-OUT TIMING
    

    [15]. G-15 Cable and Harness Connections Edition FA 3012, 16 May 1961. Effective ECO 1119. publ. Customer Engineering, Bendix Computer Division of The Bendix Corporation. (1.2 Mb).

    [16]. Algebraic Compiler for the Bendix G-15, T21-1, December 1960 publ. Bendix Computer Division of The Bendix Corporation. (Description of ALGO language - programming instructions).

    [17]. Programming notes for the ALGO system. 27 March 1961. Technical Applications Memorandum No. 72 publ. Bendix Computer Division of The Bendix Corporation. (16 questions and answers about ALGO programming).

    [18]. ALGO Operating Instructions, T22, January 1961 publ. Bendix Computer Division of The Bendix Corporation. (Comprehensive operating instructions).

    [19]. DA-1 Programming Manual Edition APR-03581-3, June 1961, supersedes T5-2, March 1958 publ. Bendix Computer Division of The Bendix Corporation. (1.9 Mb).

    [20]. Intercom 1000 Reference Card, side 1 and side 2. This is a pocket sized card (6" x 3.375") published by the Bendix Computer Division of The Bendix Corporation in 1958. It was kindly donated to the ACMSWA by Dr Bernie Jepson. It is the only original Intercom item we have. It seems the Main Roads Department (the original users here in Perth) developed their own alternative to Intercom, named Marcode. This was a special interpreter "primarily for use in the field of highway geometric computations ... provides an optimum balance of system features suitable for this class of program". It combined the features of Intercom 500 with some other features from the SICOM Interpretive System for the CDC 160 computers and seems to have replaced the need for Intercom. Unfortunately, the code for Marcode has been lost.

    [21]. The INTERCOM 500 Programming System for the BENDIX G-15 66 page manual, Edition APG-06611, June 1961 publ. Bendix Computer Division of The Bendix Corporation. (14.7 Mb). Scanned from an original manual kindly lent to me by Paul Horvath

    [22]. POGO Compiler for the Bendix G-15 General Purpose Digital Computer 13 page manual, Edition CB-019, January 1959 publ. Bendix Computer Division of The Bendix Corporation. (1.4 Mb). Scanned from a photocopy kindly lent to me by Rick Crowhurst

    What is available elsewhere

    One other collector who has posted information on the Web is Paul Pierce. His extensive collection includes a Bendix G-15 and, in response to our queries about Intercom, he has posted the following documents at his site:

  • ALGO (5734k)
  • Intercom 1000 Programming Manual (8893k)
  • Intercom 1000 Technical Manual double precision (7963k)
  • Intercom 1000 Technical Manual, Appendix Subroutines double precision (6196k)
  • Intercom Programming, by Wyant and Howell (9304k)
  • What we don't have

    It is hard to know what you don't have.

    Most importantly, we don't have a Maintenance Manual. But did one exist? I have been advised that a Maintenace Manual was prepared and issued with just the first few G-15 machines, but then withdrawn and replaced by references 9 to 14 listed above. As the following passage from the preface in [9] states:

    Always is a long time. I doubt they are answering calls now. It appears that Customer Engineering issued occasional maintenance bulletins and it would be nice to locate copies. One document we would particularly like to have is mentioned in [9, page 17]:

    Documents/software in the nice to have category include:

    [ 1]. The tapes or code for the ALGO compiler. The compiler comprised six magazines. #1, #2, #3 interpreted the Algo code in three stages and produced object code; #4 ran the object code and produced answers; #5 was the "updater" - some kind of editor; #6 was the "housekeeper", used to modify or expand the ALGO system. According to Bendix, theirs was the first implementation of Algol.

    [ 2]. The ALGO library of subroutines, mentioned in [15, page 23].

    [ 3]. The code for any of the 821 applications projects for which abstracts were published up until 21 January 1966, (especially of the various utilities), mainly as further examples of how to code the G-15.

    [ 4]. Various programming manuals mentioned in the December 1966 Newsletter:

  • 600 601 Intermap Programming Manual
  • 600 603 ALTRAN Reference Manual
  • 600 604 AUTOPOINT 24 Programming System Coding Manual (T-18-1)
  • 600 607 Intercom 500 Programming Manual
  • 600 626 G-15 Reference Card
  • 600 627 G-15 Fixed Point Scale
  • 600 843 Intercom 550 (SPD-04)
  • 601 535 Autocard Programming Manual
  • 601 536 Intercard Programming Manual

    [ 5]. And of course, all that interesting stuff we don't know about.

    If you can help, please get in touch.