developstopfix
Member
Hello everyone. A while back I had made a post or two on here in search of a VT100/101/102 etc. terminal. I ended up finding a nice VT101 and have been tinkering with it since. It is fully working, but the lack of AVO features on the 101 as well as slightly reduced performance compared to the other more fully-featured models had me wanting to either purchase another model or ideally swap the main terminal board, as the 101 uses basically the same design as the other cost-reduced models (VT102 and VT131). Recently a seller on eBay listed a handful of VT102 terminal boards so I purchased one but there were some unexpected issues. When powering the terminal on there was a longer than usual pause than usual and then terminal bell beeped 7 times. The screen displays error 2 which isn't very helpful because according to DEC the solution is to just replace the entire terminal board. After some poking around I figured the issue might be with the NVR chip that stores the user configurable settings because after going into the Setup screen and hitting Shift-S to write the settings to memory the terminal appeared to work fine, even after powering it off and on again. Unfortunately after leaving it powered off for a while the problem reappeared, only worse because I was now getting some scrambled text in the Setup screen and writing the settings to memory wasn't working. I considered trying to track down the cause of the issue and repairing the board myself but figured if the seller has more of these on hand I might as well just ask for a replacement, which I did. Unfortunately the replacement board I received is even worse than the first - I get the same error 2 on starting the terminal only I don't seem to be able to write settings to the NVR at all. Attempting to do so just causes the terminal to hang on the "Wait" message for about 10-15 seconds and then I get dropped back into the Setup screen only now I can't actually do anything. The 5 key doesn't switch between Setup A/B, 6 doesn't flip the bits for the actual settings, 0 doesn't reset the terminal, etc. All you can do is power off and back on again only to go through the same issue once more.
But since this is now 2 boards in a row that have similar issues it's got me thinking, am I wrong in assuming the VT102 board will work in my VT101 chassis? As far as I could tell every other part is exactly the same. I don't have a scope to see what's going on with the EL1400 NVR chip when attempting to write to it but I can at least check the voltages in all the relevant spots and they look fine. Of course I don't know how these boards were kept prior to me getting them and the seller assures they were pulled from working units but who knows. I could always try swapping the known good working NVR chip from my VT101 board onto the VT102 to see if that solves anything but I'd rather not have to resort to that. If anyone has any other suggestions I'd love to hear them.
Thanks!
But since this is now 2 boards in a row that have similar issues it's got me thinking, am I wrong in assuming the VT102 board will work in my VT101 chassis? As far as I could tell every other part is exactly the same. I don't have a scope to see what's going on with the EL1400 NVR chip when attempting to write to it but I can at least check the voltages in all the relevant spots and they look fine. Of course I don't know how these boards were kept prior to me getting them and the seller assures they were pulled from working units but who knows. I could always try swapping the known good working NVR chip from my VT101 board onto the VT102 to see if that solves anything but I'd rather not have to resort to that. If anyone has any other suggestions I'd love to hear them.
Thanks!