Reverse engineering the PRO disk format

[Farb]

I haven't heard any reason not to do so, so here are my current reverse engineering notes:

 

http://www.whizzosoftware.com/sio2arduino/prosys.html

 

Hopefully others can help fill in some of the blanks.

[Shawn Jefferson]

There was a windows app to create vapi images on a happy 1050, but i dont think it was ever officially released. Dont know why it isnt/wasnt though.

[Farb]

There was a windows app to create vapi images on a happy 1050, but i dont think it was ever officially released. Dont know why it isnt/wasnt though.

 

I'd love to play with it if it gets released.

Edited January 11, 2012 by Farb

[ijor]

I would be very interested in emulating accurate timing. Is there any recommended old reference document or book that would help in the regard?

 

Not that I know, but most of it is common sense. The disk is a rotating thing, and you must apply the rotation concept. The same sector (or two sectors aligned at the same angular position) takes one full rotation to pass again under the drive head. So you need to layout the sectors at their original position and emulate the rotation timing.

 

There are other minor issues that depend on the exact FDC behaviour, and even on the firmware. But the main idea is rotation timing.

 

There was a windows app to create vapi images on a happy 1050, but i dont think it was ever officially released. Dont know why it isnt/wasnt though.

I'd love to play with it if it gets released.

 

PM an email, and I'll send it to you.

 

There were several reason why we didn't make a fully open release. But we didn't keep it secret either, and if somebody else has a good need for it, please let me know. It requires either a Happy or a Speedy enhanced 1050. I'll try to make some final touches and see if we could really have an open release.

 

And now that you bring the issue, it reminds me that I never commented to something phaeron said above.

 

I believe it would still be possible to create a VAPI image purely with standard SIO disk read commands,...

 

I agree that it would be possible, but not much more than possible. It wouldn't be too reliable, neither too precise. Probably it would be limited, and even it would be dangerous for some disks. As we talked in other threads, some original disks (mainly, but not only, Synapse titles) can barely survive a single reading pass. If you would attempt to image those disks with the amount of passes required with a standard drive, then it would likely get completely destroyed. But yes, with some limitations and issues, it should be possible.