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evansm7 / riscix_ide

IDE driver for Acorn's RISC iX 4.3BSD
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Add support for HCCS A3000 IDE card #2

Closed rhalkyard closed 2 months ago

rhalkyard commented 2 months ago

Decided that I wanted to experience ancient Unix on my A3000, so I hacked in support for the HCCS IDE card that I have in it. Had to make a few modifications in support of this - allowing for the high-byte register to be in different locations for reads and writes, and returning the address of the following sector when probing for an ADFS volume. These shouldn't have any impact on the function of other cards, but I'm not really able to test that.

The Armstrong Walker IDEFS used by the HCCS card has a very simplistic 'partitioning' scheme - it simply has up to 4 ADFS volumes concatenated together, with no partition table. I haven't completely worked out a partitioning tool to create RISCiX partitions in this scheme, but an afternoon with a calculator and a hex editor got me a valid partition table that seems to keep both IDEFS and RISCiX happy.

rhalkyard commented 2 months ago

Changes made as requested! Thanks for catching my slip-ups.

evansm7 commented 2 months ago

Thank you, merged! 🤩