Copying DEC VAX set up disks rx50, help

[Chuck Guzis]

On 4 Mar 2007 at 7:06, Dave Dunfield wrote:

> This makes it easy to work with ANY drive type - but the downside is
> that you may have to set a data-rate translation if you are recreating
> the disk on a different drive type than the one from which it was
> recorded.

Well, 22Disk, Copyqm, etc.  doesn't ask the BIOS what's there unless 
there's no DISKETTE.CFG file anywhere in the command search path, the 
current directory, or where the command was loaded from.   At that 
point, one punts and uses the BIOS data which works for the vast 
majority of cases.

But for the oddball situation, one to specify oddball drive 
characteristics; e.g., dual-speed and double-speed drives, slow seek 
rate, lack of a change line etc.  One can define different drives for 
the same physical interface by simply assigning different drive 
letters.  Once done, it never has to be done again. 

What almost mandated this was SyDupe--customers would stack two large 
tower cases together and fill them with drives--to a maximum of 12 (3 
controllers x 4 drives each).  There was no hope for the BIOS to 
puzzle that one out.  (You could actually write 3 2D copies at once, 
but 3 HDs was a bit iffy unless you had a fast ISA bus; otherwise you 
got DMA lost data errors).

My own setup is a stack of external drive boxes with labels on them, 
calling out the drive letter used to access them and what's in the 
box.  Just plug it in and you're good to go--use the drive letter on 
the box.

Cheers,
Chuck