Here is a unique TRS-80 implemented in a homebuilt S-100 chassis. The unit
drives a monochrome composite monitor and behaves exactly like a TRS-80
Model III when running.
Most people who visit these pages are familier with early S-100 computers, many of which were homebuilt, and also the Tandy Radio Shack TRS-80 line, which were all factory produced, but have you ever seen a Homebuilt TRS-80 on an S-100 bus?
These two systems are among the most unique in my collection. They are complete implementations of a Model III TRS-80 in homebuilt S-100 chassis, using a combination of homebuilt and modified commercial S-100 cards.
Both systems run using unmodified copies of the TRS-80 Model III ROMS, and come up with the TRS-80 Model III BASIC prompt. They can run TRS-80 BASIC and machine language programs, and the unit with the disk controller boots Model III TRS-DOS exactly as if it were a factory TRS-80.
Click any photo to view a large high-resolution image.
Here is a unique TRS-80 implemented in a homebuilt S-100 chassis. The unit
drives a monochrome composite monitor and behaves exactly like a TRS-80
Model III when running.
Inside - this system has a large 13 slot S-100 backplane.
This system is currently configured as a minimal TRS-80 Model III, with
32K of memory, and no disk controller.
The cards from the S-100 TRS-80 - Clockwise from upper left:
Homebuilt TRS-80 logic card (with ROMS). Modified SSM VB1B video card
Standard WMC MEM-3 32K RAM card. Standard WAMECO CPU-2 Z80 card.
Here is the back of the homebuilt and Modified video cards.
Another TRS-80 implemented in a homebuilt S-100 chassis. This unit is exactly
like the one above, except that it has a full 64K of memory and a homebuilt
TRS-80 compatible disk controller - it even boots and runs TRS-DOS!
Inside - this system has a only a 6-slot backplane (just enough)
This system is configured as a full-blown TRS-80 Model III with 64K of
memory and a dual diskette drive system.
The cards from the S-100 TRS-80 - Clockwise from upper left:
Standard SuperRam S-100 32K memory. Standard Tanner 32K S-100 memory.
Standard WAMECO CPU-2 Z80 card. Homebuilt TRS-80 logic card (with ROMS).
Homebuilt TRS-80 disk controller. Modified SSM VB1B video card
Here is the back of the Video, TRS-80 and disk cards.
