
Marcel Erz, through his Retrostack github page, has put together a lot of modern replacements for TRS-80 Model I/III/4 parts, including motherboards, ROMs, character generators, and various plastic parts.
As of this posting, the site includes:
- Model I:
- Motherboards: Revision A, D, E, G
- ROMs: Broken out into 2×64, 2×128, 2×256, and 2×512
- Keyboards: ALPS and MX
- Power Supply with 3-D Printable Enclosure
- Mods: XRX-III
- Adapters: Keyboard, ROM, and Character Generator
- 3-D Printable Parts
- Model III and 4:
- Keyboard Adapter
- 3-D Printable Parts