Fuzix

[jscrane]

          Fuzix

---

• Disk images for Fuzix on z80pack are here
• boot.dsk is A: and hd-fuzix.dsk is drive I:

This should be easy once the enhanced drivemap.txt parsing is done.

Originally posted by @jscrane in https://github.com/jscrane/cpm80/issues/16#issuecomment-2326712413

[jscrane]

Not so easy: seems to require at least a minimal MMU.

See ports 20-23 of simio.c

However it does get as far as a banner before panic-ing:

boot.dsk: 77 128 26
hd-fuzix.dsk: 255 128 128
-
IO: unhandled OUT(22, 240)
IO: unhandled OUT(20, 8)
IO: unhandled OUT(27, 1)
IO: unhandled OUT(21, 0)
IO: unhandled OUT(21, 0)
FUZIX version 0.4
Copyright (c) 1988-2002 by H.F.Bower, D.Braun, S.Nitschke, H.Peraza
Copyright (c) 1997-2001 by Arcady Schekochikhin, Adriano C. R. da Cunha
Copyright (c) 2013-2015 Will Sowerbutts <will@sowerbutts.com>
Copyright (c) 2014-2023 Alan Cox <alan@etchedpixels.co.uk>
Devboot

panic: map overIO: unhandled OUT(29, 128)

• OUT(22, 240) set segment size to 60kB
• OUT(20, 8) initialize to 8 segments
• OUT(27, 1) initialize 10ms timer interrupts
• OUT(21, 0) select segment 0
• OUT(29, 128) call plt_monitor()

[jscrane]

This will require improving the present Memory abstraction.

Make relevant APIs in Memory virtual and override in BankedMemory. (Bank 0 is the "same" as existing Memory anyway.)

Provide APIs on BankedMemory to allocate and switch banks, as described above, while making the fixed segment (the top 4k) common to all banks.

[jscrane]

This has been implemented. However Fuzix on z80pack requires 7 segments of 60kB each. This much memory is not available on the esp32 unfortunately. In fact, only one bank allocation succeeds, all subsequent ones fail.

[jscrane]

More memory is available on the esp32s3: 512kB. (Whether all of this is available is not known.)

More information.

PSRAM is also an option. Apparently ESP32-WROVERs have it, e.g., lilygo-ttgo-t-koala-esp32-wrover