Yay, now I need some Osborne boot media!

Chuck Guzis cclist at sydex.com
Sun Nov 23 22:00:16 CST 2014

On 11/23/2014 06:53 PM, Fred Cisin wrote:
> On Sun, 23 Nov 2014, Jules Richardson wrote:
>> Some PCs will write SD, of course, although I think far fewer will write SD
>> and 128 byte sectors.
> The good news is that the Osborne single density was 256 bytes per sector.
> 10 sectors per track, single sided, 40 tracks

It's 128-byte MFM (not FM) that's the problem with a huge swath of PC 
controllers.  And, wouldn't you know it, there were a few systems using 
just that.

The National Semi DP8473 is one of the controllers that can pull that 
one off.  Apparently they reverse-engineered the NEC 765 and didn't 
reproduce the bug.  Shame on them!  Didn't they understand 
"compatibility"?  And yes, the same NS controller handles FM flawlessly.


More information about the cctalk mailing list