SD Card disk drive for C-64?

drlegendre . drlegendre at
Sat Jan 23 21:34:08 CST 2016

I can't say much about the other brands, but so far as Apple was concerned,
you're exactly correct. The Apple Disk II drives were quite 'dumb' and
required a disk controller card (installed in a slot, on the motherboard)
plus a software DOS (3.2, 3.3, etc.) loaded at startup from a bootable

If one weren't careful, it was no trouble to start up an Apple II machine,
write a nice piece of BASIC code, and then be unable to save it to disc -
as the DOS had not yet been loaded. Very annoying, but not a mistake you'd
make more than once or twice.. as loading the DOS requires a system reset,
losing anything in RAM at that time.

On Sat, Jan 23, 2016 at 8:58 PM, Eric Christopherson <
echristopherson at> wrote:

> On Sat, Jan 23, 2016, Jim Brain wrote:
> > On 1/23/2016 7:15 PM, drlegendre . wrote:
> > >" I am saying don't make a permanent hardware change to a 1541 that
> > >does not have the switches unless you really want it to be permanent
> > >because there is a software method of assigning drives that is good
> enough
> > >most of the time.  BUT if you must make it permanent and you don't have
> the
> > >external switches, consider adding some form of external switch so you
> > >don't ever have to open the case again to put it back to the default."
> > >
> > >Well then, we're having a major agreement. ;-)
> > >
> > >The device ID switch is the ultimate fix for Commodore drives, and I'm
> > >really not sure why CBM didn't incorporate one into the design - at
> least
> > >from the 1540 on upwards. Can't have cost much to add a discretely
> located
> > >access hole (or a knock-out) in the case, along with a 2-place DIP
> switch
> > >for controlling device ID.
> > But, they did.  The 1541-II, 71, and the 81 have switches.
> >
> > I would disagree on your point that Commodore should have made it part of
> > the design...
> >
> > Let's travel back in time.
> >
> > After the PET intro, Peddle designs a drive, a beast of a device, with 2
> > CPUs and it costs a fortune.  Peddle is convinced a smart drive is best,
> and
> > the delay allows other manufactures to create "dumb" drive options (saw
> one
> > at World of Commodore, forgot the name).
> How did these dumb drives interface with the computer at a software
> level? I'd think a DOS would need to be loaded somehow.
> --
>         Eric Christopherson

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