TRS-80 Model 1 Display
keit...@austin.rr.com
for a display. Any one know how to do this? Display is 20 years old. Would
like to fix it, but not something I know how to do.
Also interested in purchasing hardware.
Pete Cervasio
>My TRS-80 Video Display has failed - I once had a friend that used his TV
>for a display. Any one know how to do this? Display is 20 years old. Would
>like to fix it, but not something I know how to do.
No problem. I usually run my Model I's video into the video-in jack
on my Pentium's TV board, just to keep wear and tear on the original
monitor to a minimum. It works great! Someday I need to grab an AVI
of the Dancing Demon. :) :)
The TRS-80 Home Page has the video pinouts. The relevant subpage is
http://www.kjsl.com/trs80/mod1intern.html if you'd like to take a
look. There are also pinouts of the cassette, power and expansion
bus, as well as an ASCII schematic of the power supply.
Here's the info I have on that page regarding the video connector:
<CutNPaste>
Model 1 video connector
The TRS-80 Model 1 monitor was actually a black and white RCA
television set with most of the guts taken out. Because the chassis
was connected to the power mains, Radio Shack added an optical
isolator to help prevent shocks. The output of the TRS-80 was 5 volts
to power the optoisolator, and a standard 2 volt composite video
signal. If you want to have a bigger monitor, you can wire up a DIN
connector with pins 4 and 5 and connect that to the video input of
your TV (or VCR or whatever).
The pin connections on the Video DIN plug are:
2 1 - 5V dc (30ma max)
5 o 4 4 - Composite video
o o 5 - Computer ground
3 o o 1
</CutNPaste>
Note that when you look at the soldering side of the 5 pin DIN plug,
it's a mirror image of that (i.e. video is on the left and ground is
on the right).
I hope this helps.
Best regards,
Pete C.
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Scott Worley
>My TRS-80 Video Display has failed - I once had a friend that used his TV
>for a display. Any one know how to do this? Display is 20 years old. Would
>like to fix it, but not something I know how to do.
My Video display unit still works, but it's a little flaky... it has a
bit of a "ripple" to it. Anyway, I made an A/V cable to hook my
TRS-80 up to my TV. From a local electronics store I bought the
following parts for about $10:
10' of shielded dual audio cable
2 5-pin DIN 180-degree male plugs
2 RCA male audio plugs
Normally the dual audio cable is for L/R stereo channels, but it works
great for the composite video and mono audio. The DIN plugs will be
connected to the Video and Cassette jacks on the computer. OK, get
your soldering iron warmed up <grin>. For the video line DIN plug:
hook pin 4 (video) to the conductor, and pin 5 (ground) to the
shielding. For the audio line DIN plug: hook pin 5 (cassette out) to
the conductor and pin 2 (ground) to the shielding. The pins should be
numbered on the DIN plugs you get, and the RCA plugs are obvious in
connecting conductor and ground. Make sure you color-code or mark the
DIN plugs somehow... you wouldn't want to get them mixed up! :)
My TV has L/R stereo audio jacks, but when I hook the mono signal to
the right channel, it figures out that it's mono and drives both
speakers. It works pretty good! Hook up the ol' joystick, and soon
you'll be playing Galaxy Invasion on the big screen! :)