Compaq Portable 386 Question

[Tony Duell]

> Would a Decmate keyboard and monitor work with a Rainbow?

Well, the keyboard/monitor from a DECmate II will work, they are the same 
units (modulo different keycaps in some cases).

The keyboard is a plain LK201, the mono monitor is a VR201 (and the 
keyboard plugs into the monitor). That is just a composite monitor with 
strange connectors, The colour monitor is a VR241 (RGB monitor with 
sync-on-green).

If you don't have the colour graphics board fitted, you get composite text 
video on one pin of the monitor connector. That's what drives the VR201

If you add the colour card, an output from that is combined with the text 
video and appears on the same pin. That gives you mono graphics/text on a 
VR201, and is also the green drive signal for the VR241. 2 other outputs 
from the colour card go to the R and B inputs on the VR241. You get green 
text and colour graphics. There is anouther output from the colour card 
that is combined with the syncs and ends up on another pin of the monitor 
connector. With a sepcial cable you can link that to the green input of 
the VR241 and also connect a VR201. That way you can have text (and 
optionally mono graphics) on the VR201, and colour graphics on the VR241.


You should be able to find a file in the archives which explains the
monitor connector on the 'bow, how to link up non-standard monitors, what
happens if you have the colour card, etc. If not, I'll post it again. 

-tony