On 2015-Oct-21, at 3:19 AM, Rod Smallwood wrote:
> VT 100's have one weak point. The monitor is a bought in part from Ball Bros.
> The Ball supplied drive board burns up a diode and cap. It will be obvious
> on inspection of the board.
> I have never been able to get a circuit diagram or I'd do a replacement board.
>
> Needless to say the DEC parts are mde of sterner stuff
The VT100 FMPS from bitsaver's:
http://www.mirrorservice.org/sites/www.bitsavers.org/pdf/dec/terminal/vt100/MP00633_VT100_Schematic_Feb82.pdf
has schematics for two different monitor boards (pages PDF.43 & PDF.58), the
first indicated as being from Ball Bros.
Does that cover it?
Dates on the Ball Bros version look like 78, while the other looks like 79.
(Anecdotally: didn't have any problems with the power supply or monitor on the
VT278 when it was powered up after many years.)
