19 Nov
2007
19 Nov
'07
4:51 a.m.
Ethan Dicks wrote:
On Sun, Nov 18, 2007 at 10:11:14PM +0000, Tony Duell
wrote:
4040 and 2031 REL files were portable to 1540/1541/1571 if one simply
read the records and wrote them out. Writing it sector by sector
probably would have worked as well, but I have not done research.
8050 and on up (8250, SFD, etc.) use Super Side sectors, which made
sector copies impossible, and I think record copies only possible if the
number of records was under a sertain limit.
As I recall the 1581 used an entirely different scheme for REL files, so
all bets are probably off on that unit.
Jim
--
Jim Brain, Brain Innovations (X)
brain at jbrain.com
Dabbling in WWW, Embedded Systems, Old CBM computers, and Good Times!
Home: http://www.jbrain.com
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 .
My recollection is that in general, CBM DOS "relative" files weren't
particularly portable from DOS version to DOS version. I think you
had to understand the record structure and copy them one record at
a time. I think you might have been able to copy relative files from
one diskette to another in the same drive unit, but I never tried it,
so that's a faint memory and mere speculation.