Recent content by jdreichard

Hello @eegru, Sorry to revive this thread, nut can you share a schematic and the chips you used for your replacement RAM board for the Tandy 2000? I have some bad RAM chips but might want to build your board instead of the headache of desoldering! Thanks! Josh

I wanted to follow-up on this thread. Miraculously, I have the DEC Rainbow running. Not RAM, not ROMs, but the oscillator! Upon checking with an oscilloscope, I discovered that the pin that should have been outputting 24.07342 MHz for the rest of the system was dead as a doornail. So here's how...

I wanted to follow up on this thread. Miraculously, I have the DEC Rainbow running. Not RAM, not ROMs, but the oscillator! Upon checking with an oscilloscope, I discovered that the pin that should have been outputting 24.07342 MHz for the rest of the system was dead as a doornail. So here's how...

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: Verified PSU voltages are in-range. Checked the Z80 and swapped the 8088. Checked the ROMs (dumped and compared) Poked around for shorts on the...

Thanks Doug! I'll give that a try! I really appreciate the response!

I hope you don't mind me reviving an old thread, but I may have the same problem with my DEC Rainbow 100B as harry. I am getting all seven diagnostic LEDs at power on. The technical reference says this is "Error 30 (rom crc, rom 0)". Here's what I can verify: 1. PSU voltages are in range. 2...

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!

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...