problem with Adaptec 1542a scsi driver on UNIX

[Deepinder Setia]

I have run into a problem while writing driver for Adaptec AHA1542A 
scsi adapter on UNIX. 

All the host adapter commands I have tried (like mailbox init, adapter 
inquiry, return installed devices etc..) go through. However when I 
first issue start SCSI command, I never get any "mailbox in full" MBIF
interrupt that is supposed to signal completion of scsi command. 
The command that I issue is SCSI_TEST_UNIT_READY. The led on the 
adapter as well as drive remain lit till I power the system down.

Before I issue this scsi command, I also give "return_installed_devices"
command to adapter. The return data shows that drive is properly
installed and adapter has recognized it.

If I reverse cable direction (making it incorrect) on adapter side, 

 1. return_installed_devices does not show this drive as connected.
 2. Test by adapter firmware to recognize drive also fail.
 3. When I issue SCSI_TEST_UNIT_READY command, I get the interrupt 
	immediately but scsi status shows error in selection. This
	kind of shows that atleast my parameter passing to adapter looks ok.

Please let me know if can you help me. I apologize if this post seems
incongrous; this is the closest newsgroup I have acess to.

Thanks.

Deepinder Setia.
setia at lynx.uucp		(408)370-2233