Category: TRS-80 Model 1
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TRSDOS v2.3 for Japanese TRS-80 Model 1
Introductions The TRS-80 Model 1 was introduced to Japan in 1979, with a custom keyboard and Kana support. The keyboard PCB and ROMs were completely different. In order to support the Japanese Kana characters, multiple changes were made to the ROM, resulting in a larger ROM size and an extra ROM chip on board. One…
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TRS-80 XRX-III Mod
Introductions The XRX-III mod is a synchronous 500-baud wave shaper for the TRS-80 Model 1 computer. It greatly improved the reliability of reading data from a cassette tape. Note that this MOD is unnecessary on the latest ROM v1.3 as a fix was put in the software. Additionally, any mods for 750-baud and 1000-baud mods…
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TRS-80 Model 1 Replacement Power Supply
The objective here is to make a low-cost replacement power supply. We’d like to stay close to the original design. Picking the Transformer Below is the schematic for the original power supply. More info on the original can be found in this article. We’ll need a transformer with two center-tapped coils on the secondary side.…
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TRS-80 Model 1 Power Supply
Background I recently got my hands on a TRS-80 Model 1, but it didn’t come with a power supply. I figured not a big deal, I should be able to build one. However the more I looked in to the power supply and the available replacements, the more bewildered I got about this mysterious power…