Apple II SCSI hard drive questions
- Thread starter KennyPowers
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So an official BlueSCSI 1.1 firmware was just released that includes @jokker 's changes to support this CMS card. I flashed it and was able to get my //e booting ProDOS off of a 32MB volume 
Then I set about trying to add termination power to the CMS card so the BlueSCSI wouldn't have to be externally powered. That basically means getting +5v to pin 25 of the SCSI connector. Tracing backwards from pin 25 took me to JP2 on the CMS card. The manual simply describes JP2 as "NOT USED", and indeed the other side of JP2 goes to the anode of an unpopulated diode on the PCB (so nowhere). At first I thought, "Oh, maybe it's already wired to provide term power and I just have to populate that diode and close JP2". However, the direction of the unpopulated diode is such that it would be taking current *in* from pin 25, so no dice. In the end, I just traced +5v from the card-edge to a nearby pin on the AMD SCSI chip and bodged a diode from there to one side of JP2. Now closing JP2 provides term power on SCSI pin 25 and opening JP2 disables the modification:
Look ma...no wires!
I've also attached the ProDOS 2.4.2 image used above to this post. It was formatted with the original CMS utility and then the ProDOS volume was created with FILER...but I probably just could have used CiderPress. Anyways, it's attached in case it saves anyone some time...probably works with other A2 SCSI cards too.
Then I set about trying to add termination power to the CMS card so the BlueSCSI wouldn't have to be externally powered. That basically means getting +5v to pin 25 of the SCSI connector. Tracing backwards from pin 25 took me to JP2 on the CMS card. The manual simply describes JP2 as "NOT USED", and indeed the other side of JP2 goes to the anode of an unpopulated diode on the PCB (so nowhere). At first I thought, "Oh, maybe it's already wired to provide term power and I just have to populate that diode and close JP2". However, the direction of the unpopulated diode is such that it would be taking current *in* from pin 25, so no dice. In the end, I just traced +5v from the card-edge to a nearby pin on the AMD SCSI chip and bodged a diode from there to one side of JP2. Now closing JP2 provides term power on SCSI pin 25 and opening JP2 disables the modification:
Look ma...no wires!
I've also attached the ProDOS 2.4.2 image used above to this post. It was formatted with the original CMS utility and then the ProDOS volume was created with FILER...but I probably just could have used CiderPress. Anyways, it's attached in case it saves anyone some time...probably works with other A2 SCSI cards too.
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Nice write up! Thanks for posting, hopefully this helps folks that find their way hereSo an official BlueSCSI 1.1 firmware was just released that includes @jokker 's changes to support this CMS card. I flashed it and was able to get my //e booting ProDOS off of a 32MB volume
View attachment 12867
Then I set about trying to add termination power to the CMS card so the BlueSCSI wouldn't have to be externally powered. That basically means getting +5v to pin 25 of the SCSI connector. Tracing backwards from pin 25 took me to JP2 on the CMS card. The manual simply describes JP2 as "NOT USED", and indeed the other side of JP2 goes to the anode of an unpopulated diode on the PCB (so nowhere). At first I thought, "Oh, maybe it's already wired to provide term power and I just have to populate that diode and close JP2". However, the direction of the unpopulated diode is such that it would be taking current *in* from pin 25, so no dice. In the end, I just traced +5v from the card-edge to a nearby pin on the AMD SCSI chip and bodged a diode from there to one side of JP2. Now closing JP2 provides term power on SCSI pin 25 and opening JP2 disables the modification:
View attachment 12868 View attachment 12866
Look ma...no wires!
View attachment 12870
I've also attached the ProDOS 2.4.2 image used above to this post. It was formatted with the original CMS utility and then the ProDOS volume was created with FILER...but I probably just could have used CiderPress. Anyways, it's attached in case it saves anyone some time...probably works with other A2 SCSI cards too.
I have a non-name SCSI card that doesn't like my db25 bluescsi v2. The same bluescsi v2 works fine on my Apple SCSI card. I'd love to send you the card for diagnosis. I can also send a debug log from trying to use it with this card if that helps.
Hmm interesting, do you have decent res pictures of the front and back of the card? I'd definitely be interested in trying to get it working.
I got this card 25+ years ago in a used IIGS I had purchased. It came with a CMS External SCSI Drive so I had always thought it was a CMS SCSI Card. Comparing my pictures with pictures of actual CMS SCSI cards has me thinking this is not a CMS SCSI Card.
Interesting, it definite has the look of a Apple II SCSI card but just slightly different. I know there was a CMS card that was different to the CMS II card so "maybe" it's that?
I'd definitely be happy to borrow it for awhile and see if I can get it to work.
I'd definitely be happy to borrow it for awhile and see if I can get it to work.