PDP-8.co.uk » My Machines

PDP-8’s for sale

Toby Russell — Mon, 07 Jun 2010 08:39:08 +0000

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:

PDP-8/M, 8KW core, M8655 serial UART, very clean machine in working order
PDP-8/E, 4KW core, M8650 UART, requires a full rebuild
PDP-8/A, 16KW core, extended memory, serial, paper tape drive and controller (non DEC). Very clean and in working order
RX8E + RX01 drives
PC8E + PC04 paper tape
DECmate III
WP78 (aka a VT78)

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

PDP-8/A Documentation

Toby Russell — Sun, 23 May 2010 18:30:53 +0000

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
firmware/	20-Dec-2009 17:59	-

PDP-8/L Documentation

Toby Russell — Thu, 13 May 2010 21:51:41 +0000

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

Toby Russell — Thu, 13 May 2010 15:57:22 +0000

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

Toby Russell — Sat, 08 May 2010 18:46:07 +0000

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

Toby Russell — Sat, 08 May 2010 18:29:12 +0000

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

Click here to view the embedded video.

Photos of the new PDP-8/E

Toby Russell — Sat, 08 May 2010 13:59:31 +0000

[Show as slideshow]

New Arrival – PDP-8/E

Toby Russell — Thu, 06 May 2010 20:05:49 +0000

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

Toby Russell — Wed, 22 Jul 2009 20:41:17 +0000

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…

[Show as slideshow]

INVENTORY: OMNIBUS spares

Toby Russell — Mon, 20 Jul 2009 20:08:04 +0000

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)