towson@AMSAA.ARPA (SECAD) (04/16/85)
Roel de Heij posted a note to net.micro, which was relayed to me by a
friend. The note described a problem with the ZRT80 terminal board by
Digital Research Computers of Texas. Line inserts and deletes, as done
by popular screen editors, caused random characters to appear and disappear
on the screen.
I too have experienced this problem, and the cause has been traced
to the Mostek 2K static RAM used for the screen memory. I do not know
whether:
1. Digital Research Computers got a bad lot of chips, or
2. the Mostek chip has a different timing scheme than the chip
originally used in the design of the ZRT80 (6116), or
3. the chips being supplied are just too slow.
But in any case, a phone call to Mr. Ewing Waymire at DRC, (214)225-2309,
resulted in a speedy remedy - a new chip by a different vendor. Both my
office-mate and I have had this problem with our newly acquired ZRT80's,
and Mr. Waymire has taken care of both of us. From this, we know that
chips from both Synertek and Hitachi have worked satisfactorily. But the
Mostek chips just didn't cut it.
Dave
towson@amsaa.arpa