The TRS-80 Model 100 portable officially allowed for RAM expansion to 32k and an external acoustic coupler for the model. What other upgrades and peripherals exist for the Model 100? I had one of these second hand, and they have great battery life and true portability (about 3 lb) unlike most of the 80s portables which weighed 16 or even 28 lb!

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    Are you only interested in the original official stuff, or are you also looking for modern hacks, upgrades, etc? The resulting answer is pretty much going to just be a list of things. Are there any specific features you are missing on it that you would like or any task you are trying to do that it can't currently?
    – mnem
    Sep 20, 2016 at 23:05
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    Weird! I watched Dave's EEVblog teardown of one of these just yesterday! He said you could get a number of tech manuals: yep! See eevblog.com/2010/10/05/… Sep 21, 2016 at 11:20
  • The YouTube clip is here: youtu.be/Prl6D7bqQo8 Sep 21, 2016 at 11:20
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    I would be interested in both the official stuff and modern hacks to add new capacities to the Model 100. I sold by TRS-80 Model 100 but I've upgraded my IIgs with both standard upgrades like 1 meg of additional RAM whatisthe2gs.apple2.org.za/apple-1meg-ram-expansion and more modern cards like a flashram hard disk whatisthe2gs.apple2.org.za/microdrive-ide . Sep 22, 2016 at 20:07

1 Answer 1


As you mentioned, you could upgrade TRS-80 Model 100's RAM to 32k. You can also get a REX chip, which uses the ROM expansion slot to provide additional flash memory.

The TRS-80 Model 100 had several peripherals available (in addition to the acoustic coupler) including a cassette recorder, an external drive, a barcode reader, printers, and even a "Disk/Video Interface" that allowed you to connect up to two 184k disk drives and a TV or video monitor... enter image description here

You could even use a "null modem" to connect the 100 to other TRS-80 computers to transfer files.

Here's a link to the user manual. The peripheral connection guidelines are in Appendix A.

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    I used a serial cable to connect the TRS-80 Model 100 to my PowerMac G3 233 using the ClarisWorks terminal module to talk to the TRS-80. The TRS-80 manual explains how to transfer programs over the serial cable from another computer. Sep 27, 2016 at 14:26
  • In reference to the peripheral above, I have a Disk Video Interface box that's in nice shape that I'd love to get to a good home. Before they were discontinued in the 1980's, they were sold pretty cheap and I couldn't resist.
    – jwettroth
    May 4, 2018 at 15:11
  • @jwettroth I'd totally take that off your hands, but I'm not sure my Model 100 will ever run again.
    – user12
    May 6, 2018 at 12:21
  • @jwettroth If you still have it and the offer still stands, I would be very interested in giving your DVI a good home (see profile for contact info).
    – Matthew H
    Feb 19, 2019 at 2:38

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