MAINDECs passed by the PDP-8/E Simulator

Most of the MAINDEC hardware diagnostic programs do not depend on exact timing and can be run successfully on slow Macintoshs or with the simulated PDP-8/E running as fast as possible. In case of doubt, the MAINDEC passes with the PDP-8/E and the I/O devices set to run with real time speed running on a sufficiently fast Macintosh (that is a 140 MHz Power Mac for the PDP-8/E Simulator 1.x version or a Mac with an Intel Core 2 Duo CPU for the 2.x version).

Serval of the hardware diagnostics create pretty patterns in the PDP-8 memory, as seen in the Memory Content plug-in window of the PDP-8/E Simulator. Some screenshots of this window are attached to this page.


MAINDEC-8E-D0AB-PB Instruction Test Part 1 (Binary)
MAINDEC-8E-D0AB-D Instruction Test Part 1 (Documentation)

MAINDEC-8E-D0BB-PB Instruction Test Part 2 (Binary)
MAINDEC-8E-D0BB-D Instruction Test Part 2 (Documentation)

MAINDEC-8E-D0CC-PB Adder Test (Binary)
MAINDEC-8E-D0CC-D Adder Test (Documentation)

From a note of Bob Supnik: Start at 0200 with SR=0000. Runs about 35 minutes without any output until the very end (unless error). Then prints as an acceptance indicator on the console:


MAINDEC-8E-D0DB-PB Random AND Test (Binary)
MAINDEC-8E-D0DB-D Random AND Test (Documentation)

MAINDEC-8E-D0EB-PB Random TAD Test (Binary)
MAINDEC-8E-D0EB-D Random TAD Test (Documentation)

MAINDEC-8E-D0FC-PB Random ISZ Test (Binary)
MAINDEC-8E-D0FC-D Random ISZ Test (Documentation)

MAINDEC-8E-D0GC-PB Random DCA Test (Binary)
MAINDEC-8E-D0GC-D Random DCA Test (Documentation)

MAINDEC-8E-D0HC-PB Random JMP Test (Binary)
MAINDEC-8E-D0HC-D Random JMP Test (Documentation)

MAINDEC-8E-D0IB-PB Basic JMP-JMS Test (Binary)
MAINDEC-8E-D0IB-D Basic JMP-JMS Test (Documentation)

MAINDEC-8E-D0JC-PB Random JMP-JMS Test (Binary)
MAINDEC-8E-D0JC-D Random JMP-JMS Test (Documentation)

MAINDEC-8E-D1AA-PB MM8E 4K Memory Checkerboard (Binary)
MAINDEC-8E-D1AB-D MM8E 4K Memory Checkerboard (Documentation)

MAINDEC-8E-D1EC-PB Memory Address Test (Binary)
MAINDEC-8E-D1EC-D Memory Address Test (Documentation)

MAINDEC-8E-D1GB-PB PDP-8/E Memory Power On/Off Test (Binary)
MAINDEC-8E-D1GB-D PDP-8/E Memory Power On/Off Test (Documentation)

The PDP-8/E Simulator version 1.3 (or later) passes this test “better” than a hardware PDP-8/E. After turning off the PDP-8/E with the power key of the KC8-EA Console, the simulator quits. After restarting the simulator, you only must operate the continue key of the console, you need not to load restart address 0201 because the simulator not only preserves the memory content, but the register content, too. (With older versions of the simulator, you must save the configuration explicitly because they do not save the current PDP-8/E state in the preferences file of the simulator automatically.)

KM8-E Memory Extension

MAINDEC-8E-D1BB-PB KM8-E 4K Extended Memory Checkerboard (Binary)
MAINDEC-8E-D1BB-D KM8-E 4K Extended Memory Checkerboard (Documentation)

The original documentation is not available. Set SR9-11 to the number of memory fields to check. After each successful cycle, the digit “5” is printed on the teletype. Set SR5 or SR4 to halt the test and set SR3 to avoid relocating of the program.

MAINDEC-8E-D1FB-PB PDP-8/E Extended Memory Address Test (Binary)
MAINDEC-8E-D1FB-D PDP-8/E Extended Memory Address Test (Documentation)

MAINDEC-8E-D1HA-PB PDP-8/E Memory Extension and Timeshare Test (Binary)
MAINDEC-8E-D1HA-D PDP-8/E Memory Extension and Timeshare Test (Documentation)

Thanks to Willem van der Mark for the scan of his original documentation.

KE8-E Extended Arithmetic Element

MAINDEC-08-DHKEA-A-PB KE8-E EAE Extended Memory Exerciser (Binary)
MAINDEC-08-DHKEA-A-D KE8-E EAE Extended Memory Exerciser (Documentation)

MAINDEC-8E-D0LB-PB KE8-E EAE Instruction Test Part 1 (Binary)
MAINDEC-8E-D0LB-D KE8-E EAE Instruction Test Part 1 (Documentation)

MAINDEC-8E-D0MB-PB KE8-E EAE Instruction Test Part 2 (Binary)
MAINDEC-8E-D0MB-D KE8-E EAE Instruction Test Part 2 (Documentation)

RK8-E Disk Cartridge System

Note that the following paper tapes MAINDEC-08-DHRKA-B-PB, MAINDEC-08-DHRKB-E-PB, MAINDEC-08-DHRKC-H-PB and MAINDEC-08-DHRKD-A-PB contain some ASCII text before the leader that must be overread before they can be loaded with the BIN loader.

MAINDEC-08-DHRKA-B-PB RK8-E Diskless Control Test (Binary)
MAINDEC-08-DHRKA-E-D RK8-E Diskless Control Test (Documentation)

A table for translating the addresses from the listing of the E version documentation to the B version binary.

MAINDEC-08-DHRKB-E-PB RK8-E Disk Drive Control Test (Binary)
MAINDEC-08-DHRKB-G-D RK8-E Disk Drive Control Test (Documentation)

When PDP-8/E Simulator 1.x runs with PDP-8/E real time speed, this MAINDEC sometimes halts with a STATUS REGISTER ERROR at PC:2054 in TST28, the consecutive sector timing test, or at PC:2132 in TST29, the non-consecutive sector timing test. The tests use a 2.5 ms resp. 40 ms delay loop to check if the READ ALL and WRITE ALL commands are able to act on two consecutive sectors and to check if the READ and WRITE commands need a complete disk revolution (that takes 40 ms) to access consecutive sectors. The internal timing of the simulator is not precise enough to always meet this conditions. The faster the Mac is, the more likely these tests pass. PDP-8/E Simulator 2.x runs this test without any problems.

A table for translating the addresses from the listing of the G version documentation to the E version binary.

MAINDEC-08-DHRKC-H-PB RK8-E/RK8-L Data Reliability Program (Binary)
MAINDEC-08-DHRKC-H-D RK8-E/RK8-L Data Reliability Program (Documentation)

This MAINDEC runs about 16 hours for a RK8-E with four RK05 drives.

MAINDEC-08-DHRKD-A-PB RK8-E/RK8-L Disk Formatter Program (Binary)
MAINDEC-08-DHRKD-D-D RK8-E/RK8-L Disk Formatter Program (Documentation)

TC08 DECtape System

Note that the TC08 DECtape Controller Maintenance Manual (table 4-1 on page 4-5) explicitly lists these TC01 MAINDECs for use with the TC08.

MAINDEC-08-D3BC-PB TC01 Basic Exerciser
MAINDEC-08-D3BB-D TC01 Basic Exerciser (Documentation)

MAINDEC-08-D3EB-PB TC01 Extended Memory Exerciser
MAINDEC-08-D3EB-D TC01 Extended memory Exerciser

MAINDEC-08-D3RA-PB DECTREX 1 TC01 Random Exerciser
MAINDEC-08-D3RA-D DECTREX 1 TC01 Random Exerciser (Documentation)

Thanks to Volker Hermann for providing the scan of the DECTREX 1 documentation and thanks to Vincent Slyngstad for hosting it on his site.

DEC-08-EUFB-PB TC01-TU55 DECtape Formatter
DEC-08-EUFB-D TC01-TU55 DECtape Formatter (Documentation)

The DECtape Formatter is very time-critical. Even when the timing precision of the PDP-8/E Simulator is set to a small value, not every run of the formatter succeeds with a correctly formatted DECtape.

PC8-E High Speed Paper Tape Reader & Punch

MAINDEC-08-DHPCAB-PB PC8-E Paper Tape Reader & Punch Diagnostics (Binary)
MAINDEC-08-DHPCAB-D PC8-E Paper Tape Reader & Punch Diagnostics (Documentation)

This is the PC8-E Diagnostics restored by Willem van der Mark, the original DEC version is available on his tests page, too. To run it, three test tapes MAINDEC-00-D2G1, MAINDEC-00-D2G2 and MAINDEC-00-D2G4 are required. This test only runs with PDP-8/E Simulator 2.x, not with the old 1.x version.

DK8-EA and DK8-EC Real Time Clock

MAINDEC-8E-D8AC-PB DK8-E Clocks Diagnostics (Binary)
MAINDEC-8E-D8AC-D DK8-E Clocks Diagnostics (Documentation)

With PDP-8/E Simulator 1.x, for all kinds of real time clocks, this MAINDEC halts at various tests because the timing resolution of the simulator is not precise enough to match the clock frequencies. PDP-8/E Simulator 2.x passes this MAINDEC for all clock speeds. (In case of doubt, a fast multi-core Mac passes the timing tests better when all but two cores are turned offline using the “cpuctl” utility.)

DKC8-AA Real Time Clock

MAINDEC-08-DJDKA-B-PB DKC8-AA Option Test #1 (Binary)
MAINDEC-08-DJDKA-B-D DKC8-AA Option Test #1 (Documentation)

PDP-8/E Simulator 2.x only has the clock of the DKC8-AA I/O option board, so it only passes the Real Time Clock Timing Test (section 4.6).

VC8-E Point Plot Display Control

MAINDEC-08-DHVCA-A-BP VC8-E Display Diagnostic (Binary)
MAINDEC-08-DHVCA-A-D VC8-E Display Diagnostic (Documentation)

The Control Logic Test 1 regularly fails in the tests CTL3-DILX and CTL3-DILY because the timing resolution of the simulator is not precise enough to always match the 21 µs delay loop that is repeated many times during the tests. Tests 15–17 seem not to be prepared to work with two screens, e. g. the Color Alignment Test 17 for the VR-20 draws the green cross on the first VR-20 and the red cross on the second VR-20.

TSC8-75 Board

TSC8.SV V2.003 TSC8-75 Hardware Diagnostic (Binary)
TSC8.SV V2.003 TSC8-75 Hardware Diagnostic (Documentation)

The binary can be found on the ETOS system disk and the documentation in the ETOS manuals, see here.