Restoring a VT50 (VT52 actually) .

Mattis Lind mattislind at
Tue Dec 26 16:22:07 CST 2017

2017-12-26 22:25 GMT+01:00 Fritz Mueller via cctalk <cctalk at>:

> > On Dec 26, 2017, at 3:25 AM, Mattis Lind via cctalk <
> cctalk at> wrote:
> >
> > … Instead I came up with a small
> > circuit (well stole actually from the VT100 schematics) that generated a
> > composite video signal from the TTL signals generated by the VT52…
> Oh — this is a cool idea!  Will keep in the bag of tricks if necessary for
> future work on the VT52.
> > @Fritz: You don't need to get a dump of the PROMs in your terminal. I
> think
> > the ones I have is in pretty good shape.
> You beat me to it!  I think I will still upgrade my PROM sockets over this
> holiday break, and will just go ahead and dump the PROMs while I’m at it
> since I’ll have them out anyway.  Mine are labeled the same as the ones you
> listed.

Good idea! It is always good to check so that they match in case I got the
dump wrong.

Before putting everything together I also dumped the chargen ROM board:

Since it is dumped at the outputs of the board it is AFTER the set of
inverting 7404s used on the chargen board.


>   cheers,
>     —FritzM.

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