.
It's a TTL CPU, using a modest number of TTL chips and all simple ones. Available as a kit too.
Video: Hack42 Lecture: The Gigatron by Walter Belgers and Marcel van Kervinck
From the project on hackaday.io:
Quote:
This is what we have now:
• 8-bits system built out of 1970s TTL chips (74LS)
• 34 TTL ICs, or 930 logic gates, for the CPU proper
• No microcontroller and no complex chips (such as the 74181 ALU)
• Only simple ICs, such as AND/OR, 4-bit adders, multiplexers, registers and so on
• 6.3 MHz. Might be pushed to 8 MHz
• 32kB 70ns RAM
• Harvard architecture with EPROM for program/data
• Operates on 2.5W, or below 0.5W for the 74HCT version
• RISC with pipelining: 1 instructions per clock (sometimes 2...)
• Instruction decoding with diodes
• Nice instruction set: ADD/SUB/AND/OR/XOR, conditional jumps, many useful addressing modes
• 60Hz 64 color VGA and 4 sound channels bit-banged from software
• Designed and built on a solderless breadboard in 6 weeks
• 8-bits system built out of 1970s TTL chips (74LS)
• 34 TTL ICs, or 930 logic gates, for the CPU proper
• No microcontroller and no complex chips (such as the 74181 ALU)
• Only simple ICs, such as AND/OR, 4-bit adders, multiplexers, registers and so on
• 6.3 MHz. Might be pushed to 8 MHz
• 32kB 70ns RAM
• Harvard architecture with EPROM for program/data
• Operates on 2.5W, or below 0.5W for the 74HCT version
• RISC with pipelining: 1 instructions per clock (sometimes 2...)
• Instruction decoding with diodes
• Nice instruction set: ADD/SUB/AND/OR/XOR, conditional jumps, many useful addressing modes
• 60Hz 64 color VGA and 4 sound channels bit-banged from software
• Designed and built on a solderless breadboard in 6 weeks
It can run a Mandelbrot demo, or a racer-style game, or a scroller-style game:
Edit: see also this previous thread.
