Re: [hatari-devel] Problem with SCSI initiator command register

[Uwe Seimet <Uwe.Seimet@xxxxxxxxx>]

Hi,

> I didn't follow the whole discussion on SCSI, but what does this 
> transition in fffa23 helps to measure for SCSI ? Could you describe the 
> logic behind it to better understand what could be missing in Hatari ?

At the core it's not SCSI-specific. I just need this code in order to
check for timeouts.
> 
> Also, relying on "standard" values after a reset seems dangerous to me, 
> a program running before yours could completly change those values or 
> even set the control register to 0 and the counter would never 
> decrement. Or maybe some TOS/Emutos versions would not start control 
> register in the way you expect it.

Yes, but in this case HDDRIVER would not work anymore anyway. I have to
rely on the timer in order to be SCSI-compliant as far as timeouts
during the arbitration phase are concerned, and with the code I am using I
can at least avoid a deadlock if somebody disables the timer interrupt.
And I cannot simply use the timers for my own purposes, this would
interfere with other applications.
If the timer does not run at all HDDRIVER is not able to drive the SCSI
bus. But this has never been a problem for the last 20 years, so I guess
it also won't be a problem in the future ;-).

Take care

Uwe