VT52 repair

From: Lothar Felten <lothar.felten_at_gmx.net>
Date: Mon Oct 21 21:50:58 2002

>>VT52, but I only have the power cord. Inside there is something that
>>looks like a connector, but I'm not sure if it really is one.
>
> There's a little daughterboard that plugs into one of the logic boards.
> It contains the circuitry to convert between TTL levels and current loop
> or (I guess) RS232. Do you have this board?

This board is missing. But I think I know where the connector is.
I do have a mini self made board, it might belong to the VT52 (maybe
someone made a replacement?) It has 10 pins (would fit into the VT52,
but the VT has 11...) a couple of diodes a SN75188 and a SN75189. The
cable (six wires, RS 232?) is cut off. could this be the missing board ?
It definitly came with the VT52, ant it doesn't belong


> If you get no other replies, I know I have the VT52 printset. Be warned
> it's not an easy device to debug unless you're used to it. It's basically
> a special-purpose processor + firmware ROMs, and about 90% of the
> circuitry has to be working to get a display. But there are clearly tests
> you can do to eliminate the sillys (like 'is the master clock running' :-))
>
> -tony

thanks, but if Eric Smith scans them, I hope I can start.
I'll see if I can repair it....

Thanks, lothar
Received on Mon Oct 21 2002 - 21:50:58 BST