Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!nrl-cmf!ukma!rutgers!apple!voder!pyramid!hplabs!hpda!hpcuhb!hpsmtc1!galew
From: galew@hpsmtc1.HP.COM (Gale Wolfenbarger)
Newsgroups: comp.os.cpm
Subject: Re: CP/M+ BIOS
Message-ID: <11670001@hpsmtc1.HP.COM>
Date: 10 Oct 88 15:19:44 GMT
References: <231@athertn.Atherton.COM>
Organization: Hewlett Packard, Cupertino
Lines: 40

Boy have you ever stepped into a can of worms!  I'm not sure if
I can help you or not but I'll try.  I did the last 3 or 4
releases of the als BIOS for the CPM Card but that was about 3
years ago and things are pretty fuzzy about it now.  First if
you have the version of the als CPM that works with ProDos you
are in.  With it you can make calls to ProDos and ask it to
read files for you.  As I recall there is a utility in ProDos
to convert DOS to ProDos files.  This is still not simple but a
whole lot easier than the alternative.  I don't have the
documentation on how to do this with me but it involves a
couple of extra entry points that I put in the BIOS for just
this purpose.  als should be able to supply those entry points
for you.  And if not...(sigh!) I'll try.

If you don't have the ProDos version, all is still not lost as
there are two other entry points that I added to read and write
single bytes to and from Apple memory.  So if you made a RWTS
call to read the sector from the apple diskette, you can get
the information from apple memory a byte at a time.

Finally, it is possible to make BIOS calls through BDOS by
using function 50.  (I think that is the right number).  This
function was designed for this purpose.  It will return to you
a pointer to your data in CPM memory where you can get to it.
It does all the bank switching and copying for you.  Remember
though, interleave between CPM, DOS, and ProDos are all
different.  (It's enough to make you scream!.)

als is generally pretty good about answering questions when you
can get through to them.  And when they can't eventually I hear
about it.  At one time I had documented all the new entry
points and how to use them.  But that was years ago and you
know how turnover is.

I know this is all very vague, but I warned you at the outset
that is was messy.  I hope that it helps.  By the way I am a
consultant and in your area.  If worse comes to worse I'll try
to dig out my old CPM stuff.

Happy digging.  Gale.