Overview

Date of introduction: 1969 (February or earlier).
Date of withdrawal: 1973.
Total production run: 3500?
Price: $27,900

Technology: DEC M-series flip Chip modules, as in the PDP-8/I.

Reason for introduction: This machine was developed as a follow-up to the LINC-8. Originally it was to be called the LINC-8/I, but somehow it got its own number. In effect, it was a PDP-8/I with added logic to allow it to execute the LINC instruction set.

Reason for withdrawal: The LAB-8/E and the LAB-11 (a PDP-8/E and a PDP-11/20 with lab peripherals) eventually proved the equal of the PDP-12 in practice, and LINC compatability eventually proved to be of insufficient value to keep the machine alive in the marketplace.

Compatability: This machine is fully compatable with the PDP-8/I, with additional instructions to flip from PDP-8 mode to LINC mode and back. IOT 0 could enable the API, causing trouble with later PDP-8 code that assumes IOT 0 is “Clear all flags”. Also, the DECtape instruction DTLA (6766) becomes part of a stack-oriented extension to the instruction set, PUSHJ, on late model (or field updated) machines with the KF12-B backplane.

The PDP-12 supported trapping of those LINC functions that were emulated by software on the LINC-8. This allowed it to run many LINC-8 bootable systems (but not all, due mostly incompatabilities in LINKtape support), and it allowed such things as emulation of LINKtape instructions for reading and writing disk.

The TC12F Linktape controller could, with appropriate software, read or write DECtape. This support is unreliable, and is not software compatable with the TC01 or TC08 DECtape controller.

Standard configuration: PDP-8/LINC CPU with 4K of memory, plus 110 baud current loop interface, plus output relay registers. In addition, the standard configuration included either two TU55 or one TU56 drive, with a PDP-12 only controller allowing it to handle LINCtape. In addition, a 12″ scope was always included, with a connector that can connect to a second scope.

Expandability: An analog to digital converter and multiplexor was needed to fully support knob-oriented LINC software.

Other options included:

• the KW12 programmable lab clock
• additional TU55 or TU56 drives (up to 8 transports).
• the BA12 expander box
• the PC05 paper tape reader punch (needs the BA12).

Fabritek made a 24K memory box that could be added to a PDP-8/I or PDP-12.

Survival: A few PDP-12 systems are in operating condition.

(Source: PDP8 FAQ)

Documents

	Name	Last modified	Size	Description
	DEC-12-AJAA-D_FOCAL12.pdf	25-Mar-2002 21:25	1.6M
	DEC-12-GQZA-D_FPP-12_UM.pdf	11-Feb-2002 17:35	2.5M
	DEC-12-HR1B-D_Maint_Vol_I.pdf	31-Jan-2003 21:28	12M
	DEC-12-HR2A-D_Maint_Vol_II.pdf	11-Jan-2002 03:46	6.2M
	DEC-12-HR4B-D_PDP12vol4.pdf	10-Jun-2003 00:21	6.3M
	DEC-12-SE2D-D_LAP6-DIAL.pdf	26-Mar-2002 21:43	2.9M
	DEC-12-SRZB-D_PDP12_SysRef.pdf	10-Oct-2001 15:41	16M
	FPP12A_schem_Sep73.pdf	20-Dec-2002 23:51	11M
	FPP12_schem_Sep73.pdf	20-Dec-2002 23:51	13M
	PDP12Handbook.pdf	10-Oct-2001 15:45	19M
	PDP12_MaintVol3_SchemsMar69.pdf	22-Mar-2002 02:34	19M
	TC12schem.pdf	07-Jan-2002 23:34	2.4M
	pdp-12_frontPanelPlex.jpg	19-Jun-2006 17:14	341K