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Old 24 March 2015, 14:43   #6
Toni Wilen
WinUAE developer
Join Date: Aug 2001
Location: Hämeenlinna/Finland
Age: 45
Posts: 24,556
Originally Posted by mark_k View Post
Those products are a bit weird/interesting. A small board which contains a 5380 SCSI chip and one other chip (a PAL/GAL I assume), and connects to the A4000 IDE port. So the driver code accesses the 5380 via the IDE port registers somehow. (The driver code is a bit difficult to follow. Written by the same developer who did the old C Ltd SCSI software. Too many files/layers, though this time they're all in a single driver file.)
Sounds interesting

I guess it uses CS1=1 unused register space (0 to 5, probably up to 7, those two IDE registers are not really needed) to access 5380 registers. Like IDE doublers use CS1=1 to access secondary IDE.
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