First post, by dionb
Today I was testing a pile of Adaptec AHA-2940AU PCI SCSI adapters.
In my mind they were ubiquitous, bog-standard, trouble-free devices, the quintessential PCI low-end option. Well, they are ubiquitous all right, but there's more than meets the eye to these beasts. They have a non-flashable BIOS ROM (not EEPROM) and there are various different revisions out there. In my pile I encountered:
The boards also differed. All were ASSY 967106-00 and FAB 967107-00 REV A, but two kinds were labeled PCB: CHINA and the third PCB: TAIWAN. The Taiwan PCB was golden green, the China PCB either shiny green or matte green.The China boards had FCC ID on the front side near the LED connector, the Taiwan one had it on a sticker on the back. Aside from cosmetics, the actual population of the PCBs was nearly identical, except that one shiny green board had R15 populated and not R16, where the others all had R16, not R15. Whether this was relevant I'm not sure, but this was the card with the 1.34.2 BIOS, and that BIOS didn't work on any of the others (no SCSI BIOS at boot at all), and neither of the other BIOS versions worked on this card (SCSI BIOS seems to crash, then no detection and straight through to IDE boot).
1.21 and 1.30 BIOS were - as far as I could see - freely interchangeable.
Now, to test these cards, I had two big period incorrect Quantum Atlas IV 10k 18.2GB drives, connected via SCA-to-50p SCSI adapters. ID was set to 0 and 1 (adapter ID 7). Tests were performed on an old BCM SQ-599 motherboad with SiS5511 chipset supporting PCI 2.1.
On BIOS 1.30 and 1.34.2, both drives were detected correctly and were fully usable. On BIOS 1.21 the first drive (ID 0) was detected correctly, but detection then hung/timed out and only the first drive was available. The limitation is clearly a BIOS limitation, as swapping out 1.21 and 1.30 BIOS caused the issue to stick with the BIOS chip, not the PCB.
I looked on the Adaptec site, and although it still contains support info for the AHA-2940AU, I didn't find any reference to BIOS version dependencies, just the comment that BIOS was not flashable.
- for good large drive support, you want BIOS >=1.30
- BIOS 1.34.2 only works on specific cards, and those cards don't like older BIOS.