"intelligent" disk drives

[Tony Duell]

> Sort of unavoidable because to get the 500MB/side they went to 100TPI drives.

How many tracks did they put on the disk? I know that some 100tpi systems 
were 77 track. Would it hae been a major loss to use 96tpi drives, which 
could at least have read 40 track (48 tpi) disks by double-stepping.

> 
> Not as big a problem then as it may be today, because the high price of
> the 8050/8250s tended to put them into a different market, mostly business
> and institutional, where price and compatibility with the smaller and cheaper
> units wasn't usually an issue. And of course the IEEE bus was compatible
> so you could easily convert among drives (until the serial versions came
> along) as long as you had one of the (also expensive) IEEE<>IEEE cables.

It's been a long time since I used one of these 'in anger' but wasn't 
there an issue witch copying one of the random-access file types between 
disks? (or maye between disks in different drive units). If I'm 
rememebring correctly, it means the converting between 4040 and 8050 
disks is a pain even if you haev both drive units .

-tony