Pluggable control unit
Posted: 22 Jan 2020, 05:00
What I love about the Gigatron is the software tools. The ability to write real code (basic or whatever) and see it run. This is so much better than the labor intensive method of entering machine instructions into RAM or ROM.
But this all assumes the fixed instruction set of today. Has anyone thought about making the control unit completely pluggable? It is a bit hard with the existing board layout but the idea is to replace U11, U12, U13, U14, U15, U16, and diodes with a custom design. The first one could of course be 100% compatible with Gigatron. You might even want to include the RAM and I/O enable circuitry from the expansion bus idea.
The inputs are:
But this all assumes the fixed instruction set of today. Has anyone thought about making the control unit completely pluggable? It is a bit hard with the existing board layout but the idea is to replace U11, U12, U13, U14, U15, U16, and diodes with a custom design. The first one could of course be 100% compatible with Gigatron. You might even want to include the RAM and I/O enable circuitry from the expansion bus idea.
The inputs are:
- IR0-7, and CLK1
- A15
- EL, EH, PL PH, IX, XL, YL, OL, LD
- AL, AR0-3
- /WE (actually /WE_RAM and /WE_PORT)
- /OE (actually /OE_RAM and OE_PORT]
- A15_RAM and A16_RAM