Re: RF74 Disk

["Maciej W. Rozycki" <macro%orcam.me.uk@localhost>]

On Tue, 6 May 2025, Paul Koning wrote:

> >    It's not critical but the completionist in me would love to know
> > that the disks I create in the emulator could be dumped onto their
> > physical counterparts and not hang off the end.
> 
> Yes, that's what you'd expect from emulated disk container files.  But 
> that will be true so long as the sector count matches, given that you'd 
> just be using dd or equivalent.  If you were actually using at the 
> physical device at the physical recording level you'd likely see all 
> sorts of other stuff not visible to software, like spare sectors, block 
> remapping, and fun stuff like that.  If you were building a 
> plug-compatible RF74 emulation (a device that could plug into an RF74 
> controller) you'd have to worry about that, like David Gesswein's famous 
> MFM disk emulator.  But for virtual disks you see none of that.

 Well, the original question was exactly for the total number of sectors.  
Of DSSI disks I only have one working and one broken RF31 device (doesn't 
spin up or something; the firmware can be talked to), so sadly I can't 
help by examining a specimen.

  Maciej