4 Feb
2007
4 Feb
'07
8:14 p.m.
On 04/02/07, Marvin Johnston <marvin at rain.org> wrote:
I've got a CBM 8032 that powers up
"fine", but the screen is filled with "!" on
every other character position. When some letters are repeated, they can change,
i.e. "nnnn" becomes "onon" which seems like (without checking the
ASCII charts)
that the "n" and "!" are ORed to become the "o". Anyone
have any ideas what the
problem might be? Most of the schematics I have are buried someplace, so I
thought I would start here.
Display RAM problem? Looks like the LSB, could be the UC5 (2114) RAM
chip, the 74LS373 latch whos designation I can't make out on the
schematic... or the UB4 (74LS244) driver... or any number of other
things.
Joe.