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Need advice on DEC RAINBOW adapter

I'll be interested to see how your keyboard adapter goes. I have several LK201s, but I dislike them because they just take up so much real-estate. Fine for a Professional 350, but awful on a VT320 on a cramped workspace.
Well I now have a real VR201 monitor. So my next step is taking this broken membrane DEC LK201AA keyboard and seeing if I can repair it. IF I disconnect the membrane from the keyboard PCB I dont get the error. So there is a pretty good chance I may be able to repair it.
 
So if my LK201 works perfectly fine on a VT320, but I get that Keyboard Erro 13 on the Rainbow... where do I look, the Motherboard? The cables have all been swapped with alternates... Keyboard and the 15 PIN. Maybe the IO chips on the MOBO that bring the signals in and out?
 
Just a bit of information from back in the 80s when LK201 were current... There was a DIRE warning from DEC about NOT using normal telephone curly cords to replace the LK201 cables, if they got damaged...

Many telephone cables are "tinsel cable" and only rated to about 100mA - the LK201 was said to draw over 1A and could cause telephone cables to overheat and/or melt.. It may only be 5V but there are 1 - 2A available (USB is only 0.5A) - so do check the cable rating if you are using a real DEC keyboard - or even a replacement and telephone cable...
 
sorry i'm late but for future readers/reference, i did actually summarize the adapter process a few months ago when i had the same problem after buying a DECmate II: https://wiki.syspro.gs/#DEC/PDP8/DECmate_II_VR201_cable_replacement.md

the OSSC is entirely optional, but if you're into retrogaming they're worth having! i suspect you can use the same instructions to adapt for a VR241 color display as well, but i haven't tried because i don't have a machine capable of outputting color. i do have a rainbow 100, but my mother is kindly holding onto it for me while i work on moving back home so i can't play with it just yet :)
 
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Scan converters. BAH. I never understood thier appeal when thier are so many good CRTS still out there.
My pock-marked VR201 monitor is just too small for comfortable use nowdays. I have an older beige 19" LCD display that I think will work just fine (with a scan converter) and look like it belongs with the DECmate II.
 
Scan converters. BAH. I never understood thier appeal when thier are so many good CRTS still out there.
i have a soft spot for CRTs but they're not exactly portable, and i can't really see one that well when i'm relaxing on the couch or in bed :D

the main appeal for me is i can get a readable picture from an N64 or a PS2 on a modern 40"+ TV, if i'm sitting down at a desk i'm gonna prefer a CRT though
 
Hello everyone, I thought I'd post here since this thread is active.

I acquired a DEC Rainbow 100B2. It cleaned it out before powering it on. I have not made a keyboard adapter yet, but I thought I would see if there was any composite output on pins 12 and 4 of the video connector. Sadly, nothing.

I reseated all of the socketed chips. Nothing.

All seven diagnostic LEDs are lit: "Fatal Error. Replace system module."

I tested the Z80 and I dumped ROM 0 and verified both are good.

i haven't tested the 8088 yet.

Any suggestions?

Thanks!

Josh
 
remove and disconnect the floppy drive and controller and try again.
Thanks for the quick reply! I removed the floppy drive controller to no avail. I also swapped an 8088 to no avail. I checked voltages on the PSU and they seem to be in range... ~5.5v, ~+/-11.5v.

Any other suggestions are appreciated!
 
I have to agree with you that on the Rainbow or Decmate II/III the LK201 is just too big and takes up too much space. On my smaller tables there is not enough room
to even set the LK201 in front of either. So I had to move them to a different table.
 
I got there with an HTTP vs HTTPS. But I do not see anything DEC related at least doing a very quick look. Maybe their cert has expired?
 
Hi again, just hoping to get a reply to my question above and some help!

I am still getting all seven diagnostic LEDs at power on.

So far I’ve:
  1. Verified PSU voltages are in-range.
  2. Checked the Z80 and swapped the 8088.
  3. Checked the ROMs (dumped and compared)
  4. Poked around for shorts on the board.
Any help or direction would be greatly appreciated!

Thanks!
 
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