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Core Memory Plane PCBs

A project log for ED-64: A discrete 8-bit computer

ED-64 will be an 8-bit computer built with discrete components, and will feature a ferrite core memory (documented as a separate project).

andrew-starrAndrew Starr 01/20/2016 at 08:353 Comments

I've just taken delivery of the PCBs for the 64-bit core memory planes:

The cores themselves will reside in the central holes, with the X and Y select lines running between the pin headers. There are 4 FFC (flat flexible cable) connectors around the outside for running the X and Y lines through the stack, and 2 JST headers on the left for the SENSE and INHIBIT lines.

8 of these PCBs will stack to make a 64-byte memory, and the stack will plug into a panel via pin headers on the bottom plane. The panel will have the line drivers, sense amplifier and flip-flops for shuttling data in and out of the memory.

I will need to do some experimentation with a single plane before proceeding to the final panel design.

Discussions

Andrew Starr wrote 01/22/2016 at 20:18 point

25...8 for data stack, 8 for return stack, 8 for main memory, and 1 for experimentation

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Yann Guidon / YGDES wrote 01/22/2016 at 20:49 point

makes sense... But only one spare ?

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Yann Guidon / YGDES wrote 01/21/2016 at 12:57 point

Wow, you ordered about 20 PCB !

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