DEC PDP-12, System Number 696

This December 1973 vintage PDP-12 was originally purchased by the Leesona Corporation in Warwick, RI. It was used to test a pneumatic computer (ALPS) that was an accessory to a weaving machine. It has some special I/O that was added by Leesona and is connected to the LINC Sense Lines. The in 2015 dollars this machine would cost $310,000.

The architecture of this system is a merge of a LINC (Laboratory Instrumentation Computer from MIT) and a PDP-8/I, so it has two modes for the processor, LINC and PDP-8/I. A single I/O instruction changes the instruction stream from one processor mode to the other. The LINC processor manages the digital and analog I/O, graphics, and the LINCtape. The PDP-8/I processor handles the disk, diskette, and other peripherals.

This system was built very late in the life of PDP-12s, so it has the Priority Interrupt and Data Multiplexer options pre-wired in the backplane. It also has an Omnibus expansion chassis so that it could have a large (2.5MB) disk drive.

The RX02 diskette drives and the RX8-E controller, and the paper tape reader/punch and the PC8E controller came from Brown & Sharpe.

Current Status:

    • The processor and memory have been working well for more than six months.

    • The RK05 disk drive, RX01 floppy disks, VR14 display, paper tape reader/punch, both serial ports, analog inputs, relay outputs, and speaker all work.

    • It will boot and run OS/8 from the RK05 or the RX01, including the special handlers for the PDP-12 devices.

    • We are still having problems with the TC12/TU56 LINCtapes, but we are working on it.

DEC_PDP-12_Front-Panel

The console for the PDP-12.

The indicators and switches are a combination of PDP-8/I and LINC processor functions.

Features and serial numbers from the labels in the system:

M36 #696 (System Number)

MC #619

MEM #822

PC8E #SP57779

PC04 #SP15627

TU56 #8698

KW12A #646

RX02

RK05

M22VR14 #WF 558

LP01FA #739, 5060 DP2310 80 Column, 64 Character Line Printer

Installed Options:

AD12 Analog to Digital Converter

AG12 A-D Additional PreAmps

AM12 A-D Expanded Multiplexer

DP12-B Teletype Data Phone, EIA Levels, Missing M706 in MN9, M707 in MN10

DR12 Relays and Control

EM12 Basic 4K Memory

EP12 PDP-12 Processor

KE12 Extended Arithmetic Element

KF12 Automatic Priority Interrupt

KW12-A Programmable Real-Time Clock

MC12 Memory Extension Control

TC12 LINCtape Control

VC12 Scope Control

Wired But Not Installed Options:

DM12 3 Channel Data Break MUX

KP12 Power Fail/Restart

KT12 Timesharing

TC12-F DECtape Control (This needs just 2x M216 modules so we will install this)

XY12 Plotter Control

This is the swing-out frame that holds the processor electronics.

The upper part is the 8kW core memory, analog input, and LINC tape controller.

The lower part is the combined PDP-8/I and LINC processor, the serial console interface, and the priority interrupt controller.

DW8E-PC Omnibus Expansion Chassis populated for Posibus I/O Bus Converter

4x M7102 Omnibus-Posibus Interface

M7171 Bus Control

M8357 RX8-E RX01/RX02 Diskette Controller (From Brown & Sharpe) Added

M841 LE8-0 LE8-FA LP01 Printer Controller (From Brown & Sharpe) Removed

M7104-YA, M7105, M7106, RK8F RK05 Disk Drive Controller

M840 PC8-E PC04 Paper Tape Reader/Punch Controller (From Brown & Sharpe) Added

M8320 Omnibus Bus Loads

This is the DW8E-PC Omnibus Expansion Chassis.

The boards at the top convert the Posibus I/O signals from the PDP-12 to Omnibus signals on the backplane.

The Omnibus contains an LE8-FA LP01 controller, RK8-F RK05 controller, and a PC8-E PC04 paper tape reader/punch controller.

It only supports one data-break controller per Omnibus.

We removed the LE8-FA printer controller to make room for the RX8-E controller for the RX02 floppies.

To Do:

  • Install the batteries in the RK05 disk drive.

  • Try powering the TC12 from a laboratory power supply to see if a really clean power source helps with the TC12 LINCtape controller problem.

  • Put the logic analyzer on the M222 modules and see what the tape block number signals look like.

  • Maybe replace the SN7453 E5 on the M222 module from slot AB21.

  • Look at the signal outputs from the VC20 that drive a VR14. We should be able to display the output in X-Y mode on the oscilloscope.

  • Clean the switches in the TU56 DECtape drive.

  • Run more processor and TC12 DECtape controller diagnostics. Need documentation.

Done:

    • Scan and publish more diagnostic documents. (Done)

    • Clean the fingers on the M222 modules, reload MAINDEC-12-D3AD, and try it again. (Done)

    • Bolt the two cabinets together and connect DW8E-PC Omnibus Expansion Chassis to the PDP-12 CPU. (Done)

    • Remove the Omnibus boards from the chassis, reform the caps in the DW8E-PC, and power it on. (Done)

    • Reinstall the PC8-E PC04 paper tape reader/punch controller, reform the caps in the PC04, and see if the reader/punch works. (Done)

    • Reinstall the RK8F disk controller, reform the caps in the RK05 and see if the disk works. (Done)

    • Test the RX8-E in my personal PDP-8/e. (Done)

    • Install the RX8-E in the Omnibus Expansion Chassis and connect to the RX02. (Done)

    • Replace the broken trimpot in the A225 flip-chip in slot A3. (Done)

    • Reinstall the processor cabinet fan that Dan (the donor) took apart and lubricated.(Done)

    • Determine why the JMP instruction does not mask off the upper three bits. (Done)

    • Determine why the front panel does not display the correct register state. (Tested and repaired)

    • Replace the Line fuse in the VR14 and try a slow power up with a Variac. (Blew the fuse.)

    • Fix the VR14 display. (Done)

    • Measure the ripple on the power supplies with a 'scope. (done, and again after more run time)

    • Disconnect the really noisy fan in the top of the processor cabinet. It has a bad bearing. (Done, Dan the donor oiled it)

    • Recable the VR14 and TU56. (Done)

    • Try setting the MODE switch to LINC and then press I/O Preset. (Done, and works correctly)

    • Fix the M706 flip-chip. (done)

Items that came with the PDP-12

BOX #1

  • Data Products 2310 (DEC LP01) Prints

  • AA-D319A-TA OS/8 Device Extensions User's Guide

  • DEC PDP-8A Prints

  • DEC-12-HR4B-D Maintenance Prints, Modules, Volume IV

  • DEC-12-HRZC-D VR14 User's Manual

  • DEC-08-HPDMA-A-D RK8-E, RK8-F/RK05 Maintenance Procedure

  • DEC-00-HRK05-C-D RK05 Maintenance

  • EK-RX01-OP-001 RX8/RX11 Floppy Disk System User's Manual

  • EK-RX01-MM-001 RX8/RX11 Floppy Disk System Maintenance Manual

  • MAINDEC-08-DIRXB-D-D RX8/RX01 Data Reliability/Exerciser Program

  • RK05 Engineering Drawings

  • RX8 Engineering Drawings

  • RX02 Field Maintenance Print Set

  • TU56 Engineering Drawings

  • VR14 Field Maintenance Print Set

  • DEC-12-HVRTP-A-D VR14 & VR20 Troubleshooting Procedures

  • VT52-0-4 VT52 Field Maintenance Print Set

  • ASR33 Prints and Inspection Report

  • Blank Rack filler panel mounting parts

  • EK-VT50-OP-002 VT50 Video Terminal

  • LA36 Engineering Drawings

BOX #2

    • 310B Volume 1 ASR33 Technical Manual

    • 310B Volume 2 ASR33 Technical Manual

    • Data Products 2310 Line/Printer Technical Manual, 10/2/71

    • Data Products 2310 Line/Printer Technical Manual, 10/6/70

    • DEC Diagnostic Binder Containing

    • MAINDEC-08-DHRKA-B RK8E Diskless Test, 4/19/73

    • MAINDEC-08-DHRKB-C RK8E Drive Control, 1/1/74

    • MAINDEC-08-DHRKC-C RK8E Data Reliability, 7/16/73

    • MAINDEC-08-DHRKD-A RK8E Disk Formatter, 10/2/72

    • MAINDEC-12-D0GA-A Tape Quickie, 4/21/70

    • MAINDEC-12-D3AE-D PDP-12 Tape Control 1/2, 8/12/70

    • MAINDEC-12-D3DB-D Tape Data Exerciser, 2/1/70

    • MAINDEC-12-D3FB-D Tape Data Test, 11/1/70

    • MAINDEC-12-D3GA-D PDP-12 Tape Control 2/2, 5/1/70

    • MAINDEC-12-D6BC-D VR14/VR20 Display Test, 8/1/71

    • MAINDEC-12-D6CC-D A to D Test, 9/21/70

    • MAINDEC-12-D7CD PDP-12 System Exerciser, 2/1/72

    • MAINDEC-12-D8AB-D Relay Register Test, 8/1/69

    • DEC-12-ADRMA-D-A PDP-12 LAP6-DIAL Programmers Reference, 1972

    • DEC-12-SRZC-D PDP-12 System Reference Manual, Dec. 1972

BOX #3

    • LINC Tapes

      • DEC-12-ADEXA-A1-AC contains:

        • PIP, PIP1, PIP2, PIP3, PIP4, PIP5, PXDXSRC, RK05BOOT

      • DEC-12-SE2E-U0 LAP-6 DIAL SYSTEM USER PROGRAM, 1971

      • DEC-12-DE3C-U0 LAP 6 DIAL SYSTEM TAPE, 1971 containing

        • PIP, CONVERT, FORCOM, FORSYS, BINLOAD, PATCH, PRTC12-F, YQ1B-PB, YQ2B-PB, YQ3B-PB, YQ4B-PB, 25F-EAE1, 25F-EAE2, 25F-EAE3, 25F-EAE4, FMAA-PA, FMAA-PA, FMBA-PA, FMCA-PA, FMEA-PA, FMFA-PA, FMGA-PA, FMHA-PA, FMIA-PA, FMJA-PA, FMKA-PA, 10UASCII, 11UASCII, 14UASCII, 15UASCII, 16UASCII, 19UASCII, 21UASCII, 22UASCII, 23UASCII, 24UASCII, 25UASCII, 28UASCII, 29UASCII, 21-U-BIN, NMRSIME, CATACALE, CAT1E, CAT1, MAGSPY, TIP1, TIP2, ADTAPE, ADCON, NMR2, NMR3, **SE3C**, L8SIM

      • DEC-12-SE4C-U0 LAP 6 DIAL SYSTEM TAPE, 1971

      • DEC-12-SEZB-U2 Demo Tape Part 2, LS 0700 RS 0000, 1971

      • DEC-12-UXZC-U0 DEMO-12 LINCTAPE, 1-7-71

      • MAINDEC-12-D7AH-00 BASIC SYSTEM DIAGNOSTIC LINC TAPE containing

        • PIP, MARC12, RIMLDR, BINLDR, CBL, CBH, ADRSLO, ADRSHI, ADRS12, RANISZ, RANJMP, JMPJMS, JMPSELF, MEMDATA, INST1, INST2, INST2A, INST2B, TC12DAEX, MEMCT, CPTST1, CPTST2, CPTST3, TTY1, TTY2, TC12F, EXTMC, EXTAT, EXTCB, EXTMC12, TC12 I, TC12 II, TAPEDATA, ADTST, RELAYTST, DISPTST, KW12A, ONOFF, CB12

      • MAINDEC-12-D8GF-U0 OPTIONAL DIAGNOSTIC LINC TAPE

        • PIP, MARK12, RIMLDR, BINLDR, DB12, DC04, VT06, LP08, PECITRE, PECITIT, PECITDRE, PECITDT, DC02F, DC02F, EAE3A, EAE3B, DP12, PWRFAIL, KW12BC, CALCOMP, SYEX12, KF12B, HSRDPUN, PT08, DF32DD, DF32DL, RF08DD, RF08MD, LINEPNTR, CARDREAD, RK8EDATA, RK8EDRIV, RK8EMAIN, RK8EFORM

      • OS/8 V-III TAPE containing

        • ABSLDR.SV, CCL.SV, FOTP.SV, PIP.SV, DIRECT.SV, RESORC.SV, BOOT.SV, BUILD.SV, HANGMN.SV, SNOOPY.SV, MOON.SV, HANGMN.BN, PING.SV, HANGMN.WD, CHESOV.PA, CHESS.SV, CHESS.SV, DIALPS.SV, CUBIC.SV, KALED.SV, EDIT.SV, MARK12.SV, SOS.BN, SOSDEF.PA, BLINK.PA, BLINK.BN, EPIC.SV, BASIC.SV, TECO.SV, PAL8.SV, EDU200.SV, CREF.SV, DESCR.TM, TC12F.SV, SSINST.WU, SOS.PA, MAGSPY.SV, TEMP.TM

      • OS/8 V-III TAPE FORTRAN containing

        • ABSLDR.SV, CCL.SV, DIRECT.SV, FOTP.SV, PIP.SV, EDIT.SV, PAL8.SV, CREF.SV, BITMAP.SV, SRCCOM,SV, BOOT.SV, RESORC.SV, DTFRMT.SV, TDFRMT.SV, RK8FMT.SV, RKEFMT.SV, DTCOPY.SV, TDCOPY.SV, CCL.BN, BUILD.SV, F4.SV, PASS2.SV, PASS20.SV, PASS3.SV, RALF.SV, LOAD.SV, FRTS.SV, LIBRA.SV, FIRLIB.RL, SOSDEF.PA, SSINST.WU, SOS.PA, SOS.BN, BASIC.SV, HLP1.FT, MARK12.SV, TC12F.SV, TECO.SV, HEATER.SV, BUILD.SV

      • OS/8 V-III TAPE containing

        • PIP.SV, XABS.SV, 8BASIC.SV, CUBIC.SV, HANGMN.BN, PING.SV, HANGMN.12, HANGMN.WD, HANGMN.SV, HANGMN.HO, ORGAN.SV, LIFE.FT, SNOOPY.SV, MOON.SV, MOON.12, KALEID.SV, KALEID.12, CHESS.BN, CHESS.SV, OS12S.WU, DHRKAB.BN, RKELES.SV, RKECTC.SV, RKERLI.SV, RKEX12.SV, DANB.BA, RK8NSYS.SV, RK8SYS.SV, BUILD.SV, RK8SYS

      • CURVG LIBRARY

      • FORTRAN

      • MAINTENANCE TAPE

      • User Tape containing EXEC, LIBRY, DISPLY

      • Data Tape, BLOCKS -132 tests of 91 modles #18

      • Backup Tape for disk unit 10 including all ALPS routines

      • 2x LINCtape with no label

  • Reader & Punch cable with M935B on the ends, marked B10 & B09

  • G848 2x TU56 Motor Drive

  • G851 TU56 Head Relay

  • G918 Photocell Amp for PC04/PC05

  • M040 8x 600 mA Solonoid Driver

  • M044 4x 100 mA Solonoid Drvier

  • M7050 2x Reader Control for PDP-8/I

  • M710 2x Punch Control for PDP-8/I

  • M715 2x Reader Clock for PDP-8/I

  • H851 Over-the-Top Connector

  • Various Module Data Sheets

  • Ground/Power Bus Strips for DEC backplanes

  • H805 Replacement Pins for Double-Sided DEC Backplane Connector

  • 1202790 Module Handles with Cable Guide, and rivets

  • AMP 60618-1 Male Mate-N-Lok Contact

  • Q-Tips

  • RK05 Head Cleaning Kit

BOX #4, Paper Tapes

    • DEC-08-A2A1-PB 8K FORTRAN Compiler, SA: 1000 (Field 1), 2/28/69

  • DEC-08-A2B5-PR 8K FORTRAN Library Subroutines, Tape 2 of 2, 2/28/69

  • DEC-08-A2B6-PB 8K FORTRAN Library DECtape I/O, 4/28/69

  • DEC-08-A2B4-PR 8K FORTRAN Library Subroutines, 1/18/69

  • DEC-08-A2C3-PB 8K-32 Linking Loader (Paper Tape Version), 10/30/69

  • DEC-08-A2C7-PB 8K-32 Linking Loader (Disk Version), 10/30/69

  • DEC-08-A2D2-PB 8K SABR Assembler (V16), 10/30/69

  • DEC-08-AJ1E-PB Utility Overlays for FOCAL, 1969, 7/9/69

  • DEC-08-AJAE-PB FOCAL 1969 + INIT, (4K, INIT), 7/9/69

  • DEC-08-CDDB-PB DDT-8, 8/14/69

  • DEC-08-COC1-PB ODT (Low), 11/10/67

  • DEC-08-COC2-PB ODT (High), 11/10/67

  • DEC-08-AFA2-PB FORTRAN Symbol Print, Use With 08-AFC1-PB Compiler, 8/8/65

  • DEC-08-AFC1-PB FORTRAN Compiler, 9/13/67

  • DEC-08-AFC3-PB Fortran Operating System, 8/67

  • DEC-08-ESAC-PB Symbolic Editor, SA=200, 2/4/70

  • DEC-08-LBAA-PM Binary Loader, 6/10/67

  • DEC-08-LMACA-A-PB MACRO 8, Replaces DEC-08-CMAB-PB, 3/28/72

  • DEC-08-LPALA-A-PB PAL III, Replaces: DEC-08-ASC1-PB, 3/28/72

  • DEC-08-NFPPA-A-PB PDP-8 23 Bit Floating Point Package, Replaces: DEC-08-YQ1B-Yq4b-PB, 1/31/72

  • DEC-08-PMP1-PB Read In Mode (RIM) Punch, Low Memory-33, 11/22/66

  • DEC-08-PMP2-PB High Memory RIM Punch 33, 11/22/66

  • DEC-08-YPPA-PB Octal Memory Dump, 11/10/69

  • DEC-08-XY1A-PB Binary Punch-Teletype (ASR33), SA:7465; SR; No. Of Blocks; Starting Address; Final Address, 10/1/69

  • DEC-08-XY2A-PB Binary Punch H.S. (PC04), LSW: 7465; RSW: # of Blocks; Blk StAdd; Blk FinAdd; etc, 6/14/83

  • Sample Program FORTRAN SYM DESK CALCULATOR

  • MAINDEC-08-D02B-PB Instruction Test Part 2B, 1/3/68

  • MAINDEC-08-D04B-PB Random JMP Test, 2/8/67

  • MAINDEC-08-D05B-PB Random JMP-JMS Test, 12/28/67

  • MAINDEC-08-D07B-PB Random ISZ Test, 12/28/67

  • MAINDEC-08-D1AC-PB Memory Power On/Off Test, 9/16/68

  • MAINDEC-08-D1EC-PB PDP-8, PDP-8/I Extended Memory Checkerboard, 11/1/71

  • MAINDEC-08-D1GD-PB PDP-8, PDP-8/I Extended Memory Controls, Change 1305 to 5010, 1313 to 5005, 7/27/70

  • MAINDEC-08-D1HA-PB PDP-8, PDP-8/I Extended Memory Address Test, 10/1/68

  • MAINDEC-08-D1L1-PM Basic PDP-8, PDP-8/I Memory Checkerboard (Low) 2/27/68

  • MAINDEC-08-D1L2-PM Basic PDP-8, PDP-8/I Memory Checkerboard (High) 6/7/68

  • MAINDEC-08-D1MA-PM2 Memory Address Test (High), 2/11/71

  • MAINDEC-08-D2PE-PB Family of 8 ASR 33/35 Teletype Test Part 1, 2/21/69

  • MAINDEC-08-D2QD-PB Family of 8 ASR 33/35 Teletype Test Part 2, 6/41/68

  • MAINDEC-8I-D01C-PB Instruction Test 1, 12/10/69

  • MAINDEC-8I-D02B-PB Instruction Test 2, 3/21/68

  • MAINDEC-12-D0AB-PB CP Test 2, (Skip and Data Test), 9/19/69

  • MAINDEC-12-D0CB-PB CP Test III, 11/1/71

  • MAINDEC-12-D0DB-PB Instruction Test Part 1, 10/1/69

  • MAINDEC-12-D0GA-PB Tape Quickie, 4/21/70

  • MAINDEC-12-D1AC-PB Extended Memory Control, 6/19/70

  • MAINDEC-12-D1BA-PB JMP Self, 9/23/69

  • MAINDEC-12-D1DA-PB Checkerboard, 10/20/69

  • MAINDEC-12-D1EA-PB Float 1's and 0's Through Memory, 9/23/69

  • MAINDEC-12-D1FA-PB Basic Memory Control Test, 2/28/71

  • MAINDEC-12-D3DB-PB Tape Data Exerciser, 2/1/71

  • MAINDEC-12-D3FB-PB Tape Data Test, 11/1/70

  • MAINDEC-12-D3AE-PB Tape Control Test, Part 1 of 2, 8/12/70

  • MAINDEC-12-D3GA-PB Tape Control Test, Part 2 of 2, 5/1/70

  • MAINDEC-12-D6BC-PB VR14, VR20 Display Test, 8/1/71

  • MAINDEC-12-D6CC-PB A to D Test, 9/21/70

  • MAINDEC-12-D7CD-PB System Exerciser, Change may be required to Operate, 2/1/72

  • MAINDEC-12-D8AB-PB Relay Register Test, 8/1/69

  • MAINDEC-12-D8CD-PB KW12A Clock Test, 12/1/71

  • MAINDEC-12-DOSA-PB KF12B Automatic Priority Interrupt, 4/5/71

BOX #5, Manuals

    • System #696 Log

    • BInder Containing

      • DEC-12-ADRMA-A-D PDP-12 LAP 6-DIAL Programmer's Reference Manual, 10/72

      • DEC-12-SE2DN-DN Suppliment to LAP 6-DIAL Programmer's Reference Manual, 12/70

      • DEC-12-SE2DN-DN1 Suppliment to LAP 6-DIAL for the RK8F, 6/73

      • DEC-12-SRZC-d PDP-12 System Reference Manual, 11/72

    • Binder Containing

      • MAINDEC-12-D1DA-D(D) PDP-12 Checkerboard, 10/20/69

      • MAINDEC-12-D1AC-D Extended Memory Control, EXTMC12, 6/19/70

      • MAINDEC-12-D1EA-D Fload 1s and 0s Through Memory, 9/23/69

      • MAINDEC-12-D8CD-D KW12A Clock Test, 12/1/71

      • MAINDEC-12-D0SA-D Automatic Priority Interrupt

      • MAINDEC-12-D2PE-D Family-of-8 ASR 33/35 Teletype Tests Part 1, 2/21/69

      • MAINDEC-12-D2QD-D Family-of-8 ASR 33/35 Teletype Tests Part 2, 6/4/68

    • Binder Containing

      • MAINDEC-12-D9CA-D PDP-12 Operating Procedure, 12/1/69

      • MAINDEC-8I-D02B-D PDP-8 Instruction Test 2, 3/21/68

      • MAINDEC-08-D02B-D PDP-8 Instruction Test Part 2B, 1/12/68

      • MAINDEC-08-D04B-D Random JMP Test, 3/25/68

      • MAINDEC-08-D05B-D Random JMP/JMS Test, 12/28/67

      • MAINDEC-08-D1MA-D Memory Address Test, 2/11/71

      • MAINDEC-08-D1L0-D Basic PDP-8, 8/I Memory Checkerboard, 6/10/68

      • MAINDEC-08-D1GD-D PDP-8, 8I, 8S Extended Memory Control, 7/27/70 with bugfix

      • MAINDEC-08-D1HA-D PDP-8, 8I Extended Memory Address Test, 3/13/68

      • MAINDEC-08-D1EC-D PDP-8, 8I Extended Memory Checkerboard, 11/1/71

      • MAINDEC-08-D1AC-D PDP-8 Memory Power On/Off Test, 9/16/68

      • MAINDEC-12-D0AB-B PDP-12 CP Test 2 (Skip and Data Handling), 9/19/69

      • MAINDEC-12-D0CB-D PDP-12 CP Test III, 11/1/71

      • MAINDEC-12-D1FA-D Basic Memory Control Test, 2/28/71

  • Binder Containing

      • DEC-12-UW3A-D TISA Time Independent Spectrum Acquisition

      • DEC-12-UW4A-D SINPRE Signal Averager

      • DEC-12-UW5A-D NMRSIM Theoretical Spectra