Televideo 925 character rom dump
guykd at optusnet.com.au
Tue Apr 23 17:35:45 CDT 2019
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?
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:
>>> 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.
>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!
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