Re: Model 1 with video fault

You can make a cable using the web available information to connect
the cpu direct to a standard composite video monitor... like the
classic black & white Security Monitors with 75 ohm direct input.

See what the cpu is doing before you go any further. The problem might
be the vertical height adjustment in the monitor.

cheers,
skipp


: Kallikak <ken.wessen@xxxxxxxxx> wrote:
: Well I got the computer discussed in this thread (http://
: groups.google.com.au/group/comp.sys.tandy/browse_thread/thread/
: 19ee89b2418f7e6d?hl=en) yesterday and have had a quick look.

: Now I can see the screen properly, it certainly does seem to be
: writing the top two lines twice, then the next two twice, and the rest
: of the character is of course missing. Unfortunately just cleaning
: and reseating the character generator ROM didn't fix the problem. :-(

: Perhaps naively, I was expecting the ICs to be socketed, but only the
: CPU, ROMs, RAM, char generator, and 1 of the video RAM chips were in
: sockets (why just 1 - does this indicate a prior repair?). Also, the
: interconnect cable was in a bad way - very stiff and fragile, and it
: made all kinds of cracking noises even with the slightest movement.
: Should I just solder a ribbon cable in its place? Are there any
: possible problems in so doing?

: As to the 74LS93's that RedSkullDC suggested might be at fault, I will
: try and test them next time as well. I was just planning to get a
: couple of replacements and slot them in, but the lack of sockets
: changed my mind and I will try and test first. :-)

: Ken

.

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