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Rainbow 100

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skriefal

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Aug 2, 2009
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I recently acquired a Rainbow 100B (100+) with color graphics board, maxed-out memory expansion board, 10MB hard drive, and tower/floor stand. The system looked interesting, and I thought it'd be nice to see this old workhouse running again -- but I didn't realize at the time that the Rainbow 100 uses a non-PC keyboard and monitor (neither of which I have).

I see that the BCC17 cable has 3 BNC plugs for the connection to the monitor. Can this be made to work with any BNC-equipped monitor, or is the DEC VR241 the only option? Also, I have a terminal keyboard made by "Link" with the RJ11 plug. Any possiblity that this might work, or is the LK201 the only option?

If I have to buy a VR241 then I suspect that the cost involved would be more than I'm willing to spend on this, in which case I'd probably try to find another hobbyist to "adopt" the Rainbow.
 
Skriefal,

On the monitor, although it would not be color, you can also use a dec VR201 (smaller monochrome monitor.) The trick with the color monitor is that it's "sync on green". I never did this, but some Sun and SGI monitors with 13W3 connectors were sync on green. The next concern would be the scanning:60 Hz V, 15.75 kHz H, 525 scan lines. I'm not sure if those Sun/SGI monitors are multisynch.

I have a VT240 terminal that can use the VR241 to display in color and I may try this someday. Of course one would need to cut off the 13W3 connector and rewire it to the DA15 on the back of the computer/terminal. Because the LK201 keyboard plugged into the monitor, one has to bring the keyboard signals into the DA15 also.

As for the LK201 keyboard, they show up on ebay. I bought one in the winter to complete the VT240 that I put together.

Lou
 
Find an older Mitsubishi Diamond Scan and it'll do SOG and support the scanning frequency. The Sun color monitors I believe are 30 KHz horizontal. Maybe some of the older multisync monitors such as a Sony 1302 might be able to support it also.
 
I've ordered the BCC17 cable. If it doesn't work with any of the monitors that I have here then I'll look for one that supports sync-on-green.
 
As for the monitor, the problem is two-fold if you want to see color:
  1. Sync-on-green, which is not overly uncommon
  2. 15KHz refresh (ala NTSC) - most monitors won't go down to that level anymore
There is hope, however. The Rainbow's monochrome signal (and technically its green signal) is a regular old composite video signal. With a little work you can construct an adapter and plug the Rainbow into any old composite monitor for monochrome operation. You can still use graphics, just not in color (16 shades of gray instead). Because of the design of the BCC17, you can pull the signal out of the green wire and use that with any composite monitor (because its actually the monochrome signal, not green, long story...).

As for the keyboard, an LK is you best bet. LK's were widespread enough, however, that yours might be a clone.
 
Thanks PrintStar. Looks like this "Link" brand keyboard won't work, btw. I'll be ordering an LK201/LK401 from eBay soon.
 
I ordered an LK401 keyboard from eBay a few days ago. It arrived today, so I hooked everything up and tried again. This time the system boots and I have video output. I'm using composite via the green (Y) output of the BCC17 cable, connected to a 37-inch Samsung HDTV (yeah... overkill, but it was conveniently located). I'll try color support later.

The system starts and displays a menu allowing me to select which drive to boot. If I select drive W (hard drive), it presents a second menu asking whether to boot CP/M-86 or MS-DOS 2.11. Both seem to boot fine, although only the MS-DOS partition has any software installed. At least I think that's the case -- I still need to track down some information on navigating around a CP/M filesystem. I've used DOS and Unix, and Apple DOS/ProDOS many years ago... but never CP/M. But the MS-DOS partition has WordPerfect 4.2, a chess program, a genealogy program, and a few other things.

The LK401 is perhaps the stiffest, most difficult-to-type-on rubber dome keyboard that I've encountered. I suppose it was intended to feel similar to some of the stiff, linear mechanical terminal keyboards that had been prevalent a few years earlier. But it works, and I probably won't be spending hours typing on it, so it'll do.
 
skriefal said:
The LK401 is perhaps the stiffest, most difficult-to-type-on rubber dome keyboard that I've encountered. I suppose it was intended to feel similar to some of the stiff, linear mechanical terminal keyboards that had been prevalent a few years earlier. But it works, and I probably won't be spending hours typing on it, so it'll do.
Click to expand...

I was never a big fan of the LK401 myself. They're just so much smaller than the LK201, though.

Good to here you have it working!
 
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