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Using the option slots

Posted: Mon Jul 03, 2023 4:29 am
by jpenner64
The NABU has 4 options slots and with the re-emergence of use for FDD, HDD, Serial, why not go a bit further......If someone more knowledgeable than me on the Z80 bus and engineering can help the community on interfacing with the bus and through the Option card slots, it might help in exploring other projects such as memory expansion, externalizing I/O to a greater degree, building upon expanded sound, SD card reader, etc

All for reverse engineering what is available, but sometimes I get lost. Perhaps some more documentation on the 4 options slots; how to work interrupts, defining registers for use in your project, bus timings, using a SBC, PIC, MCU as a bridge etc...

This is my interest, but it others might like a little more insight here.

Re: Using the option slots

Posted: Tue Jul 04, 2023 5:29 am
by greghol
There are NABU backplane based CF card, Arduino based card and a PIC18F serial/SD cards that people have done so far in various stages. I've seen a generic protoboard for the NABU too.

I have been thinking about a design for a few weeks that would adapt a RC2014/RCBus 80/40 pin card to the NABU bus with appropriate connections with jumper options if needed. I will sit down in a few days jot down the basic connection scheme. Nothing fancy. This would be something for experimenting, nothing permanent since the card would go above the current NABU cover. Mounting a card side ways would be an option much like the official NABU serial and floppy drive cards. Mounting would be more of a challenge.

I would like to do an Igloo2 Microchip FPGA design for the NABU bus as well as the RC2014/RCBus. I do have many RC2014 cards like many people and this could make it easier to get people developing quickly.

Greg