A quick morning photo. This is my Tandy TRS-80 Model 100 Portable Computer, or "M100" as we call them. Even though I grew up with Atari, Tandy has turned out to be the largest single make in my vintage computer collection - mostly thanks to these portables.

This is an 8085-powered laptop with 32kB of RAM and a 40-character by 8-line LCD display, capable of graphics and text. It runs for around 20 hours on 4 AA-sized batteries and runs software from "Option ROM" chips installed behind a trap-door in the bottom.

An important follow-up to this Toot: If you have one of these (or, honestly, ANY vintage computer) MAKE SURE YOU REMOVE THE BATTERY! And not just the AA batteries -- they have an internal memory backup battery that WILL leak and damage the board.


I bought one of these in ~1992 used for a couple of hundred bucks (via a USENET forsale group, IIRC) so that I would be able to write during the long bus rides back to my parents' house when I came home for the weekend.

I still have it. I keep meaning to see if it'll start up.

@suetanvil I do hope you've replaced or removed the memory backup battery in it so it hasn't leaked and damaged the board. That's the main issue on model 102s. On model 100s, the capacitors also leak badly, damaging the power supply section of the board.


Mine's a 100. I haven't opened the case in ages though so it's possible it's gotten ruined.


Also, fun fact: the firmware for this was one of the last software projects at Microsoft that Bill Gates personally worked on.

@48kRAM I lusted after one of these in college when my 800XL was my main machine. I now have one but haven't done anything with it. 😞

@goz Have you at least removed/replaced the memory backup battery? They leak and will damage the board

@48kRAM and be careful with PVC, Plastic and Polystyrene packaging/cases - because reactions can occur

@48kRAM no but general retro care, cases can react to rubber, plastic and polystyrene. Things like cartridges and rom cards react to vinyl casing

@48kRAM This is the internal battery in my 102. Should I replace it? Perhaps modify the computer to use a standard CR2032?

@adamd Yes, should be replaced. I would replace it with an equivalent not a coin cell.

@adamd @48kRAM Yes! Run it to a holder outside the case, so that you (or its next carer) can easily remove it while accidentally putting it away for a decade.

@48kRAM Yes get the old batteries out. Also, I have replacement internal batteries at as well as capacitors if you need them. Everyone has a model 100/102/200 should also have a rex to eliminate data loss when your batteries die..

I had a CoCo for a very short time. Had I know it had the outside support, I might have kept it longer. But I took it back for a Tandy 1000.
I've always thought that the CoCo was a decent 8 bit machine, just not very popular.

@48kRAM I absolutely *loved* that keyboard back in the day. Nothing felt like it.

@48kRAM hey, I'm currently trying to fix mine! The piece you wrote on troubleshooting a Model 100 helped me towards fixing and diagnosing mine (with an LCD issue, thankfully not a CPU problem!). When I get some time this week or next, I'm gonna do my first ever bodge wiring to sub some missing solder pads. I'm hoping I didn't blow a trace on the PCB, but if I did.....well, another skill I'll learn!

And yes, the battery is replaced. ;)

@48kRAM Heck yeah, Model T represent.

I just got mine upped to 32K and a REX# ROM.

@ann_arcana Nice! I've got 5 Tandy "slabtops" in various configurations, plus some of its cousins. Kinda fell in love with these machines. Kyocera really designed a great portable for the time.

@48kRAM I have wanted one for years but never had the money back then to bite the bullet.

Then inexplicably one turned up in Finland of all places for 100 bucks, in pretty much pristine condition, with manual and leather slip cover.

Wanted it for a writing machine but I still haven't solved getting files on and off it; all the solutions are either out of production or require more electronics skills than I have, which is none.

@48kRAM I worked at Radio Shack from 1987-1989 and sold a few of these. We referred to them as “Trash 80’s”. Thanks for posting the photos!

not totally serious 

I consider VARTA NiCads and RIFA caps as part of the guilt Germany has inflicted upon humanity. rendering products unsustainable out of pure ignorance (at minimum.)

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