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

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!

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

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	-

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

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.