04-02-2021, 01:09 PM
(04-02-2021, 12:54 AM)Ernest Wrote: If my understanding of the B-ETI is correct, the Mainboard also had differences from the normal Microbee.
It didn't have the PGC RAM or supporting chips and also I think IC16 the Bipolar PROM 82S123 was different, most likely all to do with the lack of PGC RAM.
Hi Ernest.
I just thought I would comment on the PCG RAM
I would have thought that PCG ram was still needed to include inverse characters ("reverse video").
There is no hardware support on the standard Microbee for inverse - it was provided by copying and inverting the
FONT ROM data to PCG ram.
I have a B-ETI here, although I cannot be certain that the baseboard & coreboard were a matching set as produced in
the factory. The baseboard that I have does have PCG ram in it and is stock standard.
The only thing missing from mine is the top case & badge. It wasn't working when I got it, but I've repaired it & works well.