diff options
| author | Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> | 2022-03-05 15:09:55 +0000 |
|---|---|---|
| committer | Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> | 2022-03-09 09:28:28 +0000 |
| commit | 677a4725b1c49b139b00d8eaa932676ed8620931 (patch) | |
| tree | 28bc9adb208ff5b684d0e16260f8950324b92fd4 /include | |
| parent | d4454e41d74b85c92fbca06a30622a18545aad81 (diff) | |
mac_via: make SCSI_DATA (DRQ) bit live rather than latched
The VIA2 on the Q800 machine is not a separate chip as in older Macs but instead
is integrated into the on-board logic. From analysing the SCSI routines in the
MacOS toolbox ROM (and to a lesser extent NetBSD and Linux) the expectation seems
to be that the SCSI_DATA (DRQ) bit is live on the Q800 and not latched.
Fortunately we can use the recently introduced mos6522 last_irq_levels variable
which tracks the edge-triggered state to return the SCSI_DATA (DRQ) bit live to
the guest OS.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220305150957.5053-11-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Diffstat (limited to 'include')
0 files changed, 0 insertions, 0 deletions