I was able to find some in-depth information on the LK201 keyboard, as well as the DEC mouse used with Windows 1.0 on DEC Rainbow 100 (also on later DEC VAXMates).

Linux people already have a working LK201 and LK401 keyboard, as well as a mouse driver (below, though i can't tell if it's of use) :-)

The DEC hockeypuck mouse (VSXXX-AA and -GA) had a proprietary, 7 pin 'PS/2 style' adapter and had to be plugged into the serial printer port of the DEC Rainbow 100 (via another adapter).

It was in fact a "200 counts per inch" serial mouse (4800 bps, 1 start bit, 8 data bits (LSB first), 1 parity (ODD), 1 stop bit, half-duplex) with a SIGNETICS SCN2661.

There are probably some similarities to Logitech mice (rumours say the Logitech C7 serial mouse for PC could be switched into a DEC compatible mode, at least for AutoCAD, and the DEC VAXMate mouse could be switched into a PC compatible mode via MOUSE.COM and/or MOUSE.SYS).

APPENDIX B : LK 201 Keyboard specification
(pages 357 +)

APPENDIX C : Mouse sub system; chapters C3 => C-12
(pages 403 and on)

HTML index was easy to find, only the original, 120 MB PDF was not (working mirror below):

VCB02 Video Subsystem Technical Manual
Company: Digital Equipment Corporation
Part: EK-104AA-TM-001
Date: 1987-02
Keywords: LK201


SLOW DOWNLOAD (119 MB!): http://z80cpu.eu/mirrors/oldcomputers.dyndns.org/rechner/dec/manuals/decimages/104aatm1.pdf

"News about proprietary mice made by Digital Equipment Corporation"

DEC LK201 and LK401 keyboard driver for Linux, based on sunkbd.c (C) by Vojtech Pavlik

(DEC Rainbow 100, also for DECstations + VAXstations)

Bits of information from PAGES 53 - 70 of


The mouse has two operating modes, prompt mode and incremental
stream mode. In prompt mode, which is the powerup default, the mouse generates a report in response to a request mouse position command.

In incremental stream mode, whenever the mouse moves it generates a report of that movement. It also reports a change in button position since the last report. No report is generated when the mouse is motionless and no buttons have been changed

The mouse can transmit two reports, a 3-byte position report and a 4-byte self-test report.

Table 3-1 Mouse Command Summary
ASCnValue Hex Value Function

D 44H Prompt Mode
R 52H Incremental Stream Mode
P 50H Request Mouse Position
T 54H Invoke Self-test
Zx 5AH :xx Vendor Reserved function

- - - - - - - - - - - - - - - - -
EDIT: "GPL Driver for DEC VSXXX-AA and -GA mice by Jan-Benedict Glaw <jbglaw@lug-owl.de>"


Last edited by Bavarese; 08/30/12 04:09 PM.