Project update

A project log for DIP-8 TTL Computer

Digital Information Processor - an 8-bit computer made out of 7400 series logic and some EEPROMs.

kaimackaimac 11/03/2022 at 18:082 Comments

With a few extra parts cobbled together on another eurocard, the DIP8 CPU becomes the DIP8 computer.

From top to bottom we have:

This is really just a prototype, first incarnation of the computer - hence the 32K ROM/32K RAM split which I intend to improve upon in the future.

The system runs happily at 4 MHz, so my mandelbrot test program now only takes 5 seconds. The clock can actually go a bit higher, up to at least 6 MHz, by increasing the duty cycle (only the high part of the clock needs to be 125 ns wide).

So what's next?


adam.klotblixt wrote 11/04/2022 at 18:25 point

While the 74x688 is a lovely comparator, it is a bit expensive these days. If you won't change the address page from $FFxx then a 74x30 might be a cheaper solution and has 8 fewer inputs to wire as well :)

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kaimac wrote 11/05/2022 at 10:36 point

Perfect - thank you!

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