Creating new CP/M disk from scratch
Roy J. Tellason
rtellason at blazenet.net
Sat Jun 3 01:21:03 CDT 2006
On Saturday 03 June 2006 02:08 am, Chuck Guzis wrote:
> Now, for the tough part. You need to write a CBIOS, which at a minimum,
> has your terminal I/O routines and disk I/O routines. The terminal I/O is
> going to depend on what hardware you have. The simplest is using a
> connection to a serial terminal. More complex routines may be needed if
> what you have is a video-mapped display. The disk routines aren't too bad.
> One set of them simply passes the disk parameter block information to
> CP/M; the other entry points merely store the track and sector and unit
> and transfer address of what's to be read or written and then reads or
> writes it. Part of the CBIOS is also the cold boot loader, which loads
> the DOS part of CP/M. There are other useful features in the CBIOS, such
> as punch, printer, and reader I/O as well as IOBYTE redirection, but you
> can do those later.
This is the part I keep tripping over...
> Peruse the "CP/M System Alteration Guide" for examples of how to build a
> CBIOS and a boot loader.
Google came back with _one_ hit on that, and it was just a reference in a
bibliography, with no link to the actual document. Oh well...
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