Maarten ter Huurne wrote:
>
> On Thursday 09 November 2000 02:32, you wrote:
>
> > it is possible if the diskrom is changed in such a way that DISKIO maps
> > sector 0,1,2 & 3 to CDsector 0, sector 4,5,6,7 to CDsector 1, ...
> > (now DISKIO of IDEbios returns an error when reading from CDROM.)
>
> Is it possible to implement this efficiently? I mean, in such a way that
> reading 512-byte "virtual sectors" 0..3 doesn't cause sector 0 of the CD to
> be read (and seeked!) 4 times?
it is possible to buffer the last read CDsector, but of course that will
'cost' a 2048 bytes buffer in page 3. That seems a bit 'too much' for
me.
Anyway, I don't think it is worth all the trouble to implement it: if
you want to use files from CD, just use the normal CDEX procedure.
The only thing that might be useful is: modify DISKIO in such a way that
only the first 512bytes of CDsector0 are returned. In that way, it is
possible to provide some bootcode in CDsector0 which can be used to boot
your own soft on cd with its own CDROMdrivers.
greetinx,
jon
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