PDP-8.co.uk

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

Toby Russell — Thu, 03 Jun 2010 14:48:01 +0000

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

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	-

Recent Sales

Toby Russell — Sun, 23 May 2010 18:15:53 +0000

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

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.