A view of the entrance to our permanent exhibition of home computers from the 1970s and 1980s. All devices are fully functional and accessible to our visitors.
#retrocomputing #museum #handson #oldenburg #commodorepet #applecomputer #altair8800 #tandytrs80 #commodorevic20 #ibm5150
CoCo1 Composite Video
https://www.leadedsolder.com/2025/07/15/tandy-trs80-coco-composite-mod-aquarius.html
#HackerNews #CoCo1 #Composite #Video #TandyTRS80 #RetroTech #VideoMod #CompositeVideo
When I got the CoCo, one of the big problems was the super-smeary, snowy video on the RF-out. Even though composite video is generated internally by the video circuitry of the computer, Tandy didn’t end up breaking it out to an actual port. Lots of other 8-bit machines of the era are in the same boat. Luckily, adding a composite video port to the CoCo is very straightforward! So straightforward, in fact, that I did it twice.
Oops. I thought I'd clean the heads of the disk drives on the Tandy TRS-80 before trying them with the machine. The head on the top side fell off.
It seems it was just glued on, so I applied some fresh glue and stuck it on again. The good news: this was not the boot drive. The bad news: it doesn't seem to be working. Maybe I messed up the head alignment? Guess I need to hook up the oscilloscope and check the signal coming from the head.
At least the boot drive is working, and for the first time in my life I booted up a TRS-80 from disk.
Interesting mods as well, to select between 40 and 80 track operation.
Oh, and it turned out the heads weren't that dirty to begin with, probably didn't need a clean anyway.
#RetroComputing #Tandy #TandyTRS80 #TRS80 #Electronics #ElectronicsRepair
Well, the main CPU unit is all back together and working fine, so turned my attention to the system expansion unit. Someone obviously went in there to replace the bridge rectifier, and there was some dust but otherwise it seemed OK and it powered on stand-alone. However, something is not quite right, because the computer won't boot with it connected...
Succes! After replacing the faulty video memory chip, there is no more corruption on the screen.
Next up: to inspect the expension interface box and disk drives and hook them up.
Right, thanks to the Hakko, the faulty video memory chip is out, only to discover I am out of DIP-16 sockets...
Look what finally arrived in the mail! A bunch of (supposedly) 2102 1kbit SRAM chips for the TRS-80. I can finally replace that faulty video RAM chip and continue testing the expander and disk drives.
Meet a friend to pick up some #PhilipsP2000T micro cassettes, walk away with said cassettes, two #AtariST 520s, one 1040, two monochrome Atari monitors, one #EpsonHX20, a #TandyTRS80 MC-10 with 16Kb memory expansion, a couple of 28k8 modems and some other bits and bobs. Do I have a problem?
Look what found its way to me. I wonder whether it's complete and works, but I'll have to wait till we're back home in #Sweden to find out.
It's interesting to find one here, they're not all that common in Europe. I wasn't looking for one specifically, but I won't refuse a free retro computer.
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