> >It should be possible in future to use a single program for playing
> >audiocd's on all types of interfaces, setting read-only, ... The way to go
> >is to define some new rombiosentries (for example for sending
> >commandpackets to SCSI or ATAPI devices, enabling/disabling readonlymode,
> >...)
>
> Then DPB format must be extended. If kernel is modified in order to assign
> more work area in RAM for DPBs, then no problem.
The workarea is assigned by the diskrom as far as I know: when booting
an interface, the diskromcode allocates DPB space for each connected
drive. (and the address is written in the table which starts a #f355)
So we can add some extra bytes to it without being incompatible with any
existing software :-)
>
> Note also that current DPB assigns one byte for the number of entries in
> the root directory. ZIP disks use 512! This is another reason for extend DPB.
How is the format of ZIPdisks? Is it also a DOSFAT12/16 system?
> >BTW what is the state of the DISKIO 32(24)bit entry??
>
> If we are going to modify ROM kernel, let's implement 32 bits.
>
> >What about the sectornumber itself?
> >*complete number is fetched from memory, pointed by DE
>
> Good idea.
>
> >*lowword in DE, highword from a fixed location in page3 (>#f380)
>
> Not good idea I think...
>
> >Advantages of the DE-pointer: I can't find any.
> >Advantages of the fixed address: faster
>
> I don't like the idea of modifying MSX work area...
it is only two bytes and I believe there is still some unused space
(somewhere near #FFFx ? or are all these addresses used for V9938/58
register readback?)
There are also a lot of hookentries which are probably never used (or only
the first 3 bytes of it for a jp) I think there are a lot of other
possibilities...
>
> >Question: does someone know if the output of the function is specified?? I
> >know of Carry and A-register for indicating errors. But I've read
> >somewhere also B-register for indicating the 'amount of read sectors'???
> >Is this true? (I don't think so)
>
> This is true in #4010 ROM entry.
Is this stated in an official document??
Greetz,
Jon
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