Does someone here in the group has the SVA (Sorrento Valley Associates) ZVX4 disk controller card for 8" disk drives? If so, I am hoping to get the firmware code off of the card. This would be the code present at $cX00-cXff (X being the slot it's located in) as well as the switched-in card expansion ROM area at $c800-$cffe.
If someone has the card, I could send you a small BASIC program that would save off those 2 areas to BIN files which could then be emailed. I'm doing a project with with "Apex" operating system for the Apple II, which includes software support for that particular disk controller card. I was hoping to get my hands on the firmware in order to better make sense of the Apex code that is calling the ZVX4 card.
I never had one but I knew people who did back in the day. Sadly I've lost track of all those people it having been 30+ years ago. Those were super popular with people who used CP/M, but I also knew people who used them with Apple Pascal or other software.
It would be great if someone cloned those cards. I am not sure if the (usually WD I think) chips like the 17xx those kind of floppy controller cards usually used are readily available or not. Perhaps something usable for some of them might be scavengeable off the more common PC type cards or something.
In post #2, 'softwarejanitor' wrote:
" I am not sure if the (usually WD I think) chips like the 17xx those kind of floppy controller cards usually used are readily available or not. "
Uncle Bernie comments:
Lots and lots of Western Digital floppy disk controllers are still available from the usual suspects, like Anchor Electronics in Santa Clara (they have the 2793 and the 1771-1) or my own basement, I think I have a few hundred of various types, all still in their original tubes. Most WDC FDCs support both 5.25" and 8" drives and FM and MFM modes. The older ones with the external data separator should be avoided.
So there is no reason why we should not be able to make clones of these 8" controller cards.
I even have a few 8" drives around.
- Uncle Bernie
I always wanted an 8" drive, but never had one. They were kind of elusive for the Apple II back in the day. Hard to find and usually expensive. Even being able to hook up a DSDD 5.25" drive to an Apple II would be pretty cool. Not really practical at all these days since flash storage has essentially rendered magnetic media to being a novelty for retrocomputing but who says everything has to be practical. If it was, then retrocomputing in general doesn't make any sense.
I'd be glad to post the firmware image, but I'm unable to figure out how to attach a ZIP file here.
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Keenly interested in this project, as I have a pile of 8" disks (including for the SVA Apple II system, with the modified version of DOS 3.3), and several drives. I have fallen in love with 8" floppies for whatever reason, and the idea of using them with an Apple II makes my brain smile.How do we get the Apple to talk to a WDC controller?