"intelligent" disk drives
ard at p850ug1.demon.co.uk
Sat Nov 17 15:59:02 CST 2007
> On Sat, Nov 17, 2007 at 12:40:25AM +0000, Tony Duell wrote:
> > I've never seen a 2031, but all the GPIB-interfaces double drives contain
> > 2 processors I think.
> The 2031 is very much like a 1541, but with an IEEE-488 interface rather
> than C= IEC.
Interesting. As I said, I've never seen one, in fact the only CBM GPIB
drives I've been inside are the 8050 and 8250LP.
> Prior to the 8050/8250, I think the arrangement was one 6502 to talk to
> the bus, and one 6504 to talk to the drives, but in other respects, the
I wonder why they changed? I've not got the data book in front of me,
what was the address space of the 6504? The 8050 needs 8K, I think (4K
shared RAM + ROM + I/O devices). Did the earlier drives have less shared
RAM or something?
> > The control processor ROM is in one of those 6530 RRIOT chips, which
> > makes replaicng it a little problematic...
> I have, I think, a full set of 2040 ROMs, including the right 6530, but
> most of my pre-8050 drives were originally 2040s that were later upgraded
> to the same ROMs as a 4040 (the only difference AFAIK is the label on the
I seem to remember the 2040, 3040 and 4040 were all similar. One of the
upgrades was just a ROM swap, but I thought the other upgrade involved
rather more. But as I said I never used said units.
As an aside, IMHO one of the worst mistakes commodore made was that the
8050 could not at least read the disks of the earlier drives.
More information about the cctalk