Re: (Fwd) RE: 1541IDE and 1541IDE-S

From: Pete Rittwage (
Date: 2007-11-30 19:37:21


With some simple routines reading/writing straight to $1c01 (just wait 
for byte ready signal), you could copy raw GCR track images directly to
the disk and back very fast.  As long as saving a block takes no longer
than ~32 CPU cycles (modern IDE drives have cache?) you could do it in one
revolution per track and copy the disk about as fast as you can step the
heads.  :)

You would then have a copy as good as MNIB (or Burstnibbler) could do.

This is digression, though, as compatibility is a nice plus on your
project. I could add support for this easy if I could get an interface

Pete Rittwage
C64 Preservation Project

> Hallo allemaal,
> A picture of the interface:
> Hardly to see but it is a 74LS138 on top of a 244 on top of a 245 on
> top of the 2nd 6522. The IDE connector is glued to the 40 pins custom IC.
> So far things worked out fine :) I copied a floppy to the  harddisk and
> copied it back to another floppy. So far there is only one little flaw: it
> takes about 3 minutes to create an image and 4.5 to restore one :(
> IMHO I may blame the original routines of the 1541. When creating the
> image
> I can see the harddisk LED blink about four times a second, three times
> when restoring one. Saving is slower because the 1541 automatically
> performs a verify after te writing. I'm convinced that it can be done much
> much faster using your own loading/saving routines but I'm already very
> happy that this prooves that the idea on itself works.
>  = the assembler file
>  = the basic loader and executioner
> z=0 : create an image
> run2010 -> z=3 : restore an image
> Remark: at this moment I can only save one image. The idea is asking first
> what image to use and then to alter some of the the numbers in the lines
> with DATA.
> --
>     ___
>    / __|__
>   / /  |_/     Groetjes, Ruud
>   \ \__|_\
>    \___|
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