23 Apr
2019
23 Apr
'19
3:35 p.m.
When I saw this thread I thought 'Oh, I have a 925!' Which was working last time
(years ago.)
But wouldn't you know. When I checked, it's a Televideo 924. Off by one.
But perhaps the character ROM content is the same?
Anyway I will see if it still works, and secure all the ROM images. Today.
I have the user manuals, but does anyone have schematics for the 925 & 924?
Guy
At 09:38 AM 23/04/2019 -0700, you wrote:
On Tue, Apr 23, 2019 at 8:25 AM Patrick Finnegan
<pat at vax11.net> wrote:
On Tue, Apr 23, 2019 at 11:02 AM Jon Elson via
cctalk <
cctalk at classiccmp.org> wrote:
The thought had crossed my mind, but only as a last resort. I'm not
entirely sure what the internal fault is, but the end result is two rows of
every character have all bits stuck "on." I've verified that the ROM
addressing is correct and that there's nothing on the output side causing
this behavior. Patrick, thanks very much for offering to read the ROM!
- Josh
Is the ROM totally bad, or just losing a few bits
here and
there? If the latter, you could probably read it out, figure
out how the rows, columns and characters are mapped, and fix it.
Considering that 925s are really common, and a replacement EPROM should be
easy to source and program, this sounds like an overly difficult approach
that will yield something different than what he wants.
Pat