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View Full Version : TRS-80 Model 4 help



atari2600a
October 22nd, 2006, 02:45 PM
I found a TRS-80 Model 4 today during Neighborhood Cleanup!!!!! (along w/ a small RGB monitor I can temporarily use in my Neo-Geo cab)

It looks like it's been in the elements, due to the mud & leaves on it. When it powers up, it displays random characters (each time different). I'm guessing a loose ROM or a short or something...

It had 2 floppies in it. I have no idea what's on them, or whether I'll be able to read from them due to their condition. (things are looking 50/50)

Does anyone know (to a better extent) what's wrong w/ it? Tomorrow, I'll have the time to crack it open...

ahm
October 22nd, 2006, 03:54 PM
You seem to have answered your own question:


It looks like it's been in the elements, due to the mud & leaves on it.

atari2600a
October 22nd, 2006, 06:06 PM
You seem to have answered your own question:

You think Mud & Leaves can conduct enough to short?

ahm
October 22nd, 2006, 08:50 PM
You think Mud & Leaves can conduct enough to short?
You think they belong in there?

chuckcmagee
October 22nd, 2006, 09:07 PM
See if you can clean all the gunk out of it and LET IT DRY. I have done the "let's spill a cup of coffee into our keyboard" trick before. I just drained all the coffee out of a hole in the case and let it dry for a day. Works great to this day.

atari2600a
October 22nd, 2006, 09:25 PM
Well I opened it up an hour ago, & removed what was actually very little dried up leaves. (no mud at all). Nothing was out of place, & I made sure all the IC's where seated properly. It still doesn't work.

I thought maybe it might be the Floppy drives, so I unplugged them from the mobo, & it made no difference. I plugged them back in, & now they spin the floppy infinitely.

Does anyone know what the problem is?

Erik
October 23rd, 2006, 04:26 AM
The latest problem is likely the cables were plugged in wrong (backwards or off a pin) but the original problem is likely something more involved although you can try re-seating the chips. . .

kb2syd
October 23rd, 2006, 04:51 AM
Does anyone know what the problem is?

Get the model 4 technical manual from http://www.trs-80.com. Make sure you get the right one. See if you have a gate array version or a non gate array version. Get the manual printed closest to the manufacture date of your machine. You may have to get the 4/4p combined manual too.

Ira puts limits on his downloads, but for a couple of dollars he'll send some DVDs with copies of all the manuals he has.