Category Archives: ttl cpu

This 6502 Made From 74-Series Logic Can Run At 20 MHz

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If you always wished you could get closer to the hardware with the 6502 in your classic microcomputer you’re in luck, because [Drass] has created a beautiful implementation of a 6502 using TTL logic chips. What makes it special is that it sits on a very neat set of PCBs, and due to its use of 74AC series logic it can run at much higher speeds than the original. A 20 MHz 6502 would have been revolutionary in the mid-1970s.

Through a flying ribbon cable, it can plug directly into the 6502 socket on classic microcomputers, and the website shows …read more

Continue reading This 6502 Made From 74-Series Logic Can Run At 20 MHz→

This 6502 Made From 74-Series Logic Can Run At 20 MHz

Posted on by

If you always wished you could get closer to the hardware with the 6502 in your classic microcomputer you’re in luck, because [Drass] has created a beautiful implementation of a 6502 using TTL logic chips. What makes it special is that it sits on a very neat set of PCBs, and due to its use of 74AC series logic it can run at much higher speeds than the original. A 20 MHz 6502 would have been revolutionary in the mid-1970s.

Through a flying ribbon cable, it can plug directly into the 6502 socket on classic microcomputers, and the website shows …read more

Continue reading This 6502 Made From 74-Series Logic Can Run At 20 MHz→

1MHz, 2 Boards, 4 Bits and a Homebrew CPU

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[Agp.cooper] saw a vintage 4Kx4 bit RAM chip and decided that it needed a CPU design to match. The TTL design fits on two boards and has a functional front panel.

This custom CPU project has a few interesting bits worth noting. First, it is small enough that you can wrap your head around it pretty easily. And [Agp.cooper] gives  a good account of the instructions set architecture choices he considered and why he settled on the final design.

Another interesting twist is the testing. Each of the boards can mate with an Arduino which will exercise and test its …read more

Continue reading 1MHz, 2 Boards, 4 Bits and a Homebrew CPU→