PDP-8’s for sale

I’ve decided to sell of a few PDP-8’s as the hoard is getting rather large at the moment and so I’m prepared to part with the following:

Email offers to toby@pdp11.co.uk . Machines are located in UK


VIDEO: TMOC demonstration of their Straight-8

Some nice videos here on YouTube from the National Museum of Computing in Bletchly Park, UK demonstrating their Straight-8:

YouTube Preview Image YouTube Preview Image YouTube Preview Image YouTube Preview Image
http://www.youtube.com/watch?v=OyDufWHsNVEYouTube Preview Image[youtube]http://www.youtube.com/watch?v=OyDufWHsNVE[/youtube]

PDP-8/E Rebuild – Part 1 – Strip Down

A new arrival in my collection was a fairly clean PDP-8/E chassis. The box came with no cards but I have sufficient spares to populate.

First step in rebuilding it is to strip it down and remove all the foam gunk before moving onto reviving the power supply.

Here are some pictures from the strip down


PDP-8/I and PDP-11/40 for sale on Ebay

A great looking pair of machines have come up on Ebay that should have all us enthusiasts salivating. A PDP-8/I and an 11/40. The 11/40 comes with a PC05 paper tape drive and both are in H960 racks with their header panels.  If only I wasn’t a) penniless and b) on the wrong side of the globe!

Full details are here


PDP-8/A Documentation

[   ] EK-8A002-MM-02_PDP8A_UsersMan.pdf 21-Apr-2003 02:21 37M
[   ] EK-FPP8A-MM-001_FPP8-A_Maint_Sep76.pdf 24-Aug-2007 02:02 7.8M
[   ] EK-FPP8A-OP-001_FPP8-A_UsersMan_Dec76.pdf 22-Jan-2007 00:45 1.0M
[   ] EK-KL80A-OP-001_KL8-A_jan78.pdf 19-Dec-2003 06:19 3.6M
[   ] EK-KT08A-UG_jul78.pdf 19-Aug-2001 21:44 1.8M
[   ] EK-MS8CD-TM-001_MS8-C_MOS_Memory_Technical_Manual_Sep80.pdf 24-Aug-2007 17:56 2.0M
[   ] FPP8-A_EngrDrws_Feb76.pdf 06-Oct-2006 17:56 2.8M
[   ] KC8-A_engrDrws_Dec74.pdf 12-Mar-2003 19:42 1.2M
[   ] KC8-A_schem.pdf 29-Oct-2003 20:39 1.2M
[   ] MP-00KL8-A0_KL8-A_Engineering_Drawings_Dec75.pdf 14-Jun-2009 19:03 2.7M
[   ] MP00057_FPP8-A_Mar76.pdf 22-Jan-2007 00:37 6.3M
[   ] MP00415_8Asemi_Schem_Apr81.pdf 21-Jun-2005 20:26 21M
[   ] PDP8A_Schems_Apr81.pdf 28-Mar-2002 17:19 21M
[DIR] firmware/ 20-Dec-2009 17:59 -

Recent Sales

A few PDP-8s have come up recently on Ebay. Here is a summary of the highlights:

PDP-8/L

This PDP had lived its last 30 years on a barn, although the pictures don’t look too bad. Internally very clean and looks like it has a complete set of cards including memory. The outside is not so pretty much probably mostly surface rust and dirt although it does have one missing toggle key.

Sold for $1026.99 / £710 which seems a fair price for such an early machine

PDP-8/M

Described as being ‘museum quality’, this very clean PDP-8/M came nicely loaded with 16KW of memory (non DEC Plessey core cards), programmers console,  a serial interface and the extended memory/timeshare module (required for >4KW of memory). The machine was in full working order.

Sold for $3050 / £2110. This I feel is a very high price with the buyer prepared to pay a premium for such a clean and working machine.

PDP-8/M

From the same seller as the 8-L above, this 8/M is in cosmetically fair condition looking clean on the inside but suffering from some surface rust on the outside. The machine comes with the basic front panel (which is fairly unusual), extended memory/timeshare option and 8KW of memory. Interestingly it lacks any form of bootstrap which it would really need in order to get it to do anything useful.

Sale price $677 / £468 which I feel is about spot on for what is a very restorable machine.

PDP-8/A

Recently removed from real world service in CNC machines, a very clean and well specified PDP-8/A coming with programmers console, 16KW of core, option and extended option boards. Seller also had seperately a paper tape reader (non DEC) and controller.

Sale price £341.78 which is about correct for the less desirable -A’s


PDP-8/L Documentation

[   ] DEC-8L-D0BA-D_KP8L_Power_Failure_Option_Functional_Description_Apr69.pdf 24-Aug-2007 19:21 204K
[   ] DEC-8L-D4BA-D_MC8-L_FuncDescr_Jun70.pdf 22-Feb-2008 03:05 1.1M
[   ] DEC-8L-D4BA-D_MC8L_Memory_Extension_Control_Option_Functional_Description_Apr69.pdf 24-Aug-2007 19:22 2.0M
[   ] DEC-8L-HR1B-D_8LmaintVol1.pdf 17-Oct-2003 04:33 5.0M
[   ] DEC-8L-HR2A-D_8Lschem_Feb70.pdf 17-Oct-2003 04:32 2.7M
[   ] DEC-8L-I1AA-D_MC8-L_Inst_Mar70.pdf 22-Feb-2008 03:05 271K

PDP-8/L: Card Locations

This table details locations of cards on a PDP-8/L backplane. I’ve put it together to aid in working out what is missing from my 8/L. I believe it to be accurate but you are encouraged to double check!

SLOT A B C D
1 G921 – PDP-8/L control panel
2 M220 M113 M111
3 M220 M700
4 M220 M216 M115
5 M220 M113 M310
6 M220 M216 M310
7 M220 M111 M310
8 M617 M617 M216 M310
9 M617 M617 M115 M160
10 M160 M160 M119 M216
11 M115 M216 M117 M113
12 M160 M111 M115 M113
13 M160 M113 M117 M111
14 M115 M119 M113 M310
15 M162 M119 M113 M310
16 M162 M162 M111 M216
17 G020 M162 M360 M617
18 G020 G020 G221 G221
19 G020 G020 G221 G221
20 G020 G020 G610
21 W825 Memory Stack
22 W825 G611
23 G228 G228 G221 G221
24 G228 G228 G221 G221
25 G624 G624 G220 G220
26 G624 G624 M002
27 G826 M623 M623
28 G785 M115 M623
29 M715 M660 M906
30 M795 M660 M906
31 M718 M707
32 M516 M986 (?) M706 -
33 M516 M986 (?) M452 M076 cable
34 M111 M983 (?) M901 cable M903 cable
35 M111 M983 (?) M903 cable M908 (?) cable
36 M783 M983 (?) M903 cable M903 cable
Key:

Optional data break interface
Optional memory parity
Optional power fail
Optional high speed reader and/or punch


PDP-8/E Documentation

The following documentation is available as PDFs for the PDP-8/E (source Bitsavers)

[   ] DEC-8E-HMM3A-C-D_MaintVol3.pdf 04-Jul-2002 02:11 26M -
[   ] DEC-8E-HR1C-D_8eMaint_Feb73.pdf 14-Oct-2003 23:39 13M -
[   ] DEC-8E-OCASA-B-D_CAPS8_UG.pdf 03-Jul-2003 01:14 9.6M -
[   ] PDP-8E_ECO_LOG_Dec74.pdf 31-Dec-2008 21:36 41M -
[   ] PDP-8E_IPB_Feb74.pdf 21-Nov-2007 19:01 826K Illustrated parts breakdown
[   ] PDP8E_MaintCourseHandouts.pdf -

Videos: Musical PDP-8s

Here are a collection of You Tube videos featuring PDP-8s playing music:

YouTube Preview Image YouTube Preview Image

Photos of the new PDP-8/E


New Arrival – PDP-8/E

A rather nice new arrival for my collection is a PDP-8/E. The machine is in 3 H960 racks and has a pair of RK05 drives and a pair of Magtape drives (with pertec interfaces).  The 8/E has an expansion box giving a total of 40 slots. The machine has 12KWof memory, 3 x serial ports and a posibus interface. Alas there were no disk packs with the RK05s although I do have one 16 sector pack (unique to PDP-8s)

The machine was owned by a local company who had it in the basement of their country house and they were the owners from new. Removal required us to get the machine up a very steep and narrow staircase and so we had to dismantle the machine considerably in order to get it out. Careful notes and pictures were taken to aid in reassembly.

The machine is going to get pride of place in my office alongside my PDP-11/70 and PDP-8/Ms.


PDP-8/M (number 2) returns to life

My second PDP-8/M is just about back in the land of the living. I followed largely the same process as with the restoration of my first 8/M. Luckily this examples case wasn’t corroded and so I didn’t bother respraying and left it in original condition.

The main sticking point with getting this machine back was a failed +5V and +15V rail on the PSU. Being no expert on PSUs and having been mildly ‘warning’ zapped by it when I decided to see if anything obvious was failed, I had a hunt for a company to perform the repair.

I opted for Electronic Repair Centre Limited after some internet searches. I was very impressed with their service, which was fast and very well priced. I thoroughly recommend them to anyone looking to get a power supply repaired.

After getting the PSU back, I reassembled the machine and with a bit of CPU board swapping (3 of the originals turned out to be failed), I now have a mostly working machine. The one gotcha I currently have is that on entering the DEC accumulator counting test, the accumulator counts at full bore and cannot be seen neatly increasing on the console. My suspicion is that the line time clock might be the cause of this.

The investigation continues…


INVENTORY: OMNIBUS spares

Here are a list of my spare OMNIBUS cards:

G104 MM8E 4K Memory sense/inhibit
G227 MM8E Memory X/Y drivers
H212 MM8EJ 8K Memory stack
M837 KM8E Extended Memory and Time Share Control
M8300 KK8E Major registers (x4)
M8310 KK8E Major register control (x4)
M8319 KL8A PDP-8/A 4 channel serial I/O
M8320 KK8E Bus loads (x6)
M8321 TM8E Magtape output control module
M8322 TM8E Magtape control and data break module
M8323 TM8E Magtape transport status and control module
M8327 TM8E Magtape register module
M8330 KK8E Timing board (x6)
M8335 VT8E
M8336 VT8E Video Display Clock and Frequency Divider
M8337 VT8E Video Display Line Buffer Module
M8340 KE8E Extended arithmetic element
M8341 KE8E Extended arithmetic element
M8342 LP8E Centronics printer control (replaces M8329) (x2)
M8357 RX8E RX01/RX02 interface
M840 PC8E High speed paper tape reader/punch (x2)
M8416 KT8AA PDP8A Memory Management (hex wide)
M8417 MSC8DJ PDP8A 128K MOS Memory (hex wide)
M842 XY8E X/Y Plotter Control (x2)
M8433 RL8A Disk controller for RL01/02 (hex wide)
M847 MI8EP Hardware Bootstrap Loader for RX01/RX02
M848 KP8E Power fail and auto-restart (x3)
M849 KK8E RFI shield (x4)
M860 DK8EP Programmable Real Time Clock
M865 . Console Teletype Control (current loop only)
M8653 KL8M Modem Control, used with KL8* to provide data ready stuff
M8655 KL8JA Terminal Control (UART based substitute for M8650) (x3)
M868 TD8E DECtape Control (x2)
M880 MR8E H241 daughter board. Labelled MAINDEC-08-DHMRA-A
M935 OMNIBUS bridge (joins two adjacent backplane segments) (x4)


New Haul: PDP-8/L and PDP-8/E

A couple of new machines have joined my stable, a very clean PDP-8/L and another PDP-8/E.

The /L is complete with the (somewhat important) exception of its core stack which has been lost at some point. If anyone has or knows the whereabouts of a spare stack (I believe they were common to the /I and PDP-12), please let me know. If I can’t find one I will have to resort to fabricating an alternative using NVRAM chips,although I doubt this will be trivial.

The /E is generally clean although its plexy is pretty scrappy. I quite like the dog eared look and so I will leave it this way. The console itself is missing a couple of keys although I have replacements for these. The machine came with no cards, but I have spare CPU sets and so I’m only left needing to find memory which should be achievable.


H960 rebuild

001.jpgMy PDP-8s have finally got a new home in the form of a very rusty H960 that I recovered in my recent haul.  Before fitting my -8s into it I decided to strip and respray to bring it back to its former glory.

Here are the steps I went through to achieve this:

  1. Thoroughly wire brushed all rusty areas to remove the scaly rust.
  2. Further removed the rust using a flap disk mounted on a powerdrill.
  3. Any remaining rust was neutralized with a rust inhibiter
  4. All original labels were carefully masked
  5. The rack was resprayed in 2 costs of grey primer followed by 4 coats of satin black paint.

I’m very pleased with the end results, huge improvement. Not perfect as the rust has left the metal work a little pock marked but still very acceptable.


Latest Haul – Saved from Scrap

8-m-console.jpgI’ve just taken possession of a great haul which was literally sat on a scrap heap ready to go to PDP heaven. Highlights of the find include most of a PDP-8/M, a PC04 paper tape drive, a TD8E simple DECtape controller, an ASR-33 and a H960 rack. Whilst pretty rusty having lived in a barn for a while, most of the bits look to be restorable.

The sad news is that the TU56 that was with the machine got scrapped (brings tears to my eyes!) a few weeks ago although I did manage to recover a pair of motors and the chassis.

Unfortunately the core memory sets have gone from the 8-M, although there is a slight chance I might be able to regain one of them. If not, I will have to build up a solution using SRAM/NVRAM, which whilst not exactly authentic, will get the machine back into the land of the living.

Also, amoungst the haul were a PDP-11/40 chassis, a PRIME rack and disk and a TI-990 mini computer. You can read about these on my other blog


FACT FILE: The OMNIBUS

This guide is provides comprehensive information on the OMNIBUS used in the PDP-8/E,F,M and A series of machines.

A 20 slot PDP-8/E backplane

A 20 slot PDP-8/E backplane

Overview of the bus

The OMNIBUS is a general purpose bus consisting of 144 signals.

OMNIBUS backplanes consist of 1 or more 10 slot backplanes and are normally quad width. The later 8/A is the exception to the rule where some slots, designated for core memory are five wide.

Each slot is general purpose and in theory cards can be positioned in any slot, only limited by timing and noise considerations. Due to the general purpose nature of the bus, inter-board signals are made by way of over the top H851 edge connectors.

The OMNIBUS signals are 5V based with Logic 1 represented by -0.4-0.5V and logic level 0 by 3V-5V.

OMNIBUS Signal Reference

The following signals are presented on the omnibus. (NOTE TO SELF: This map needs to be QA-ed)

Pin D1 D2 C1 C2 B1 B2 A1 A2
A +15V +5V +5V +5V
B -15V -15V -15V -15V
C GND GND GND GND GND GND GND (SP) GND
D MA8 L IR0 L IO PAUSE L TP1 H MA4 L INT STB L MA0 L EMA 0 L
E MA9 L IR1 L C0 L TP2 H MA5 L BRK PROG L MA1 L EMA 1 L
F GND GND GND GND GND GND GND GND
H MA10 L IR2 L C1 L TP3 H MA6 L MA,MS LD L MA2 L EMA 2 L
J MA11 L F L C2 L TP4 H MA7 L OVERFLOW L MA3 L MEM START L
K MD8 L D L BUS STB L TS1 L MD4 L BRK DA CT L MD0 L MD DIR L
L MD9 L E L INT I/O L TS2 L MD5 L BRK CYC L MD1 L SOURCE H
M MD10 L USR MD H N L XFR L TS3 L MD6 L LA EN L MD2 L STROBE H
N GND GND GND GND GND GND GND GND
P MD11 L F SET L INT RQST L TS4 L MD7 L INT PROG H MD3 L INHIBIT H
R DATA 8 L PULSE LA H INIT H LNK DATA L DATA 4 L RES 1 H DATA 0 L RETURN H
S DATA 9 L STOP L SKIP L LNK LOAD L DATA 5 L RES 2 H DATA 1 L WRITE H
T GND GND GND GND GND GND GND GND
U DATA 10 L KEY CTL L CPMA DIS L IND 1 L DATA 6 L RGN L DATA 2 L ROM ADDR L
V DATA 11 L SW L M3, IR DIS L IND 2 L DATA 7 L POWER OK H DATA 3 L LINK L

OMNIBUS Cards

The following OMNIBUS cards are known to exist

Module Number Option Name Description
54-9057 KC8EA PDP-8/E Programmer’s Console
54-9668 KC8FL PDP-8/F Programmer’s Console
54-9668 KC8ML PDP-8/M Programmer’s Console
. KC8AA PDP-8/A Programmer’s Console
A231 AD8EA Analog to Digital Converter
A231 AD8E Analog to Digital Converter
A232 AH8EA Multiplexor for AD8EA
A841 AD8EA Analog to Digital Converter
G111 MM8EJ 8K Memory sense/inhibit
G111C MM8EJ 8K Memory sense/inhibit
G104 MM8E 4K Memory sense/inhibit
G104C MM8E 4K Memory sense/inhibit
G105 MP8E Memory sense/inhibit
G227 MM8E Memory X/Y drivers
G227C MM8E Memory X/Y drivers
G227 MP8E Memory X/Y drivers
G233E MM8EJ 8K Memory X/Y drivers
G619 MM8E Memory stack
G619A MM8E Memory stack (B,M)
H649 MM8AA PDP8A 8K Memory stack (hex wide)
G646C MM8EJ 8K Memory stack
H650 MM8AB PDP8A 16K Memory stack (hex wide)
H212 MM8EJ 8K Memory stack
G219A MM8AA PDP8A 8K Memory control (hex wide)
G219B MM8AB PDP8A 16K Memory control (hex wide)
H220 MM8E Memory stack
H220 MP8E Memory stack
MS8DJ PDP8A 32K semiconductor memory module
M1703 . 12 bit word 8/e bus interface (input only?)
M1703C .
M1705 . dual 12 bit omnibus output interface
M1709 . Omnibus foundation module (multiword custom I/O)
M512 DK8ED
M518 DK8EP Lab Programmable Real Time Clock (requires M860)
M518 DK8EF Lab Programmable Real Time Clock with lab panel DK8ES
M518 DS8EA Schmidt Trigger
M7104 RK8E RK05 Disk Interface
M7105 RK8E RK05 Disk Interface
M7106 RK8E RK05 Disk Interface
M8300 KK8E Major registers
M8310 KK8E Major register control
M8311 MS8-AA PDP-8/A Read/Write RAM (1K)
M8311 MS8-AB PDP-8/A Read/Write RAM (2K)
M8311 MS8-AD PDP-8/A Read/Write RAM (4K)
M8315 KK8A PDP-8/A CPU board (hex wide)
M8316 DKC8AA PDP-8/A I/O serial/parallel/clock (hex wide)
M8317 KM8AA PDP-8/A bootstrap, powerfail (hex wide)
M8317 KM8AB PDP-8/A Memory extender (hex wide)
M8317YC KM8AC PDP-8/A Memory extender, bootstrap, powerfail (hex wide)
M8319 KL8A PDP-8/A 4 channel serial I/O
M8320 KK8E Bus loads
M8321 TM8E Magtape output control module
M8322 TM8E Magtape control and data break module
M8323 TM8E Magtape transport status and control module
M8326 DB8EA Interprocessor buffer
M8327 TM8E Magtape register module
M8329 LC8E Parallel interface to DEC-writer I
M833 KK8E Timing board, good only for 4K TTY systems
M8330 KK8E Timing board, replaces M833
M8330YA KK8E Timing board, replaces M8330, handles MR8E memory stalls
M8330YB KM8F Timing board, replaces M8330
M8331 TA8E DEC Cassette control
M8335 VT8E
M8336 VT8E Video Display Clock and Frequency Divider
M8337 VT8E Video Display Line Buffer Module
M8340 KE8E Extended arithmetic element
M8341 KE8E Extended arithmetic element
M8342 LP8E Centronics printer control (replaces M8329)
M835 .
M8350 KA8E External positive I/O bus interface
M8357 RX8E RX01/RX02 interface
M8360 KD8E Data Break Interface
M8365 LC8P LA180 printer control
M8366 LQP8E LQP01 printer control
M837 MC8E Extended Memory and Time Share Control
M837 KM8E Extended Memory and Time Share Control
M839 DP8EA Synchronous Modem
. DP8EB Synchronous Modem (Bell series 300 modem)
M840 PC8E High speed paper tape reader/punch
M841 LE8 Data Products line printer control
M8416 KT8AA PDP8A Memory Management (hex wide)
M8417 MSC8AA PDP8A 16K MOS Memory (hex wide)
M8417 MSC8AB PDP8A 32K MOS Memory (hex wide)
M8417 MSC8DJ PDP8A 128K MOS Memory (hex wide)
M842 XY8E X/Y Plotter Control
M843 CR8E Card reader control
M8430 KW8EW Alarm timer
M8433 RL8A Disk controller for RL01/02 (hex wide)
M847 MI8E Hardware Bootstrap Loader
M847 MI8EN Hardware Bootstrap Loader for RK8E
M847 MI8EP Hardware Bootstrap Loader for RX01/RX02
M848 KP8E Power fail and auto-restart
M849 KK8E RFI shield
M860 DK8ED Programmable Real Time Clock
M860 DK8EF Programmable Real Time Clock
M860 DK8EP Programmable Real Time Clock
M863 DR8E 12 Channel Buffered Digital I/O
. DR8EA 12 Channel Buffered Digital I/O
M866 DP8EA Synchronous Modem (Bell series 200 modem)
. DP8EB Synchronous Modem (Bell series 300 modem)
M865 . Console Teletype Control (current loop only)
M8650 KL8E Asynchronous Data Control (current loop or RS232)
M8653 KL8M Modem Control, used with KL8* to provide data ready stuff
M8655 KL8JA Terminal Control (UART based substitute for M8650)
M868 TD8E DECtape Control
M869 VC8E (requires M885)
M882 DK8EA Real Time Clock (Line Frequency)
M8830 DK8EC Real Time Clock (Crystal, 100Hz)
M884 KG8E Parity Generator Detector for DP8E
M885 VC8E (requires M869)
M935 OMNIBUS bridge (joins two adjacent backplane segments)
Credit: Doug Jones [original document]

Recent sales

Here is a review of recent known PDP-8 sales. As ever, prices appear to be heading upwards.

PDP-8/M

Ebay US sale, item #260385453584. Sold for £1023.23 / $1500.00

Original Description:

Winning Bidder will receive one (1) Complete 100% Working Digital pdp8M Computer with 8k of Iron core memory, the computer comes with the below listed boards, unit was removed from a 100% operational cnc control cabinet. Listed shipping fee for lower 48 only. (The top cover is included)

M8330 Timing Generator

M8300 Majo Registers

M8310 Major Registers Control

M837 Memory Extension Control

M847 ROM

M848 Power Fail / Auto Restart

G111 Sense Inhibit (1 of 3 8k stack)

H212 Planar Stack (2 of 3 8k stack)

G233 XY Driver (3 of 3 8k stack)

W968 I/O Interface

M849 Shield

M8320 Bus Load Module

Commentary

A very nice looking 8-M. The 8-M is a nice compact machine and this one looks like it should make its new owner very happy. The price seemed to be about spot on for a working 8-M. Interestingly its RF shield appears to be in the wrong location, I would normally expect it to sit between the CPU/options and core memory.

PDP-8/A

Ebay US sale, item #230334635912. Sold for £525.25 / $769.99

Original Description

Dec PDP-8/a computer removed from a working machine ( Wire EDM ) seems clean and in good condition but due to it’s age I cannot guarantee its operation.
Includes boards M8315 M8317 M8316 H219B G649 Power supply and an AXIS Board.

Computer has been in storage for 10+ years – it IS dusty, and needs cleaning – Collectors please note! the computer did run when removed but there is no guarantee to it’s current operation, sold AS IS because of it’s age .

Commentary

A very clean looking machine. Price was in my opinion on the high side given that the machine is the less desirable 8/A and not in known working condition. The machine has (for an 8/A) a fairly modest 8KW of core memory.


PDP-8/M Rebuild – Job checklist

To ensure nothing gets missed, I use a checklist of tasks to be done when rebuilding machines. This is the the list for my 8/M rebuild:

Completed

  1. Perform a general appraisal of machine
  2. Photograph machine in detail
  3. Remove console and cards
  4. Remove power supply
  5. Remove wiring looms and any other remaining items attached to chassis
  6. Remove backplane
  7. Clean and sand chassis
  8. Spray chassis to primer
  9. Rub down primer
  10. Respray chassis (to matt black)
  11. Clean backplane
  12. Clean wiring loom and other chassis furniture
  13. Take detailed pictures of power supply
  14. Dismantle PSU
  15. Clean power supply components
  16. Remove and reform capacitors
  17. Reassemble power supply
  18. Bench test power supply and confirm operation
  19. Reinstall power supply (but do not reconnect AC or DC at this point)
  20. Reinstall backplane
  21. Reinstall chassis furniture
  22. Power on and confirm fans are operational
  23. Reconnect AC to power supply and confirm operation of PSU
  24. Reconnect DC from power supply to backplane and confirm voltages on backplane
  25. Install minimal card set (console and CPU) and test console operation

To Do

  1. Add further earth straps – they appeared to be non existent when I got the machine and I’m far from convinced the chassis is earthed at the moment
  2. Tidy up DC wiring loom
  3. Configure and fit core memory
  4. Debug console to establish why address bit 5 isn’t working
  5. Confirm correct operation of the console
  6. Enter basic test programs and confirm operation
  7. Solve problem of some console keys catching on console plexi
  8. Repair 3 console keys that having broken pivot shafts
  9. Fit console and confirm operation
  10. Fit RX8E and confirm its working