Re: new Applicard

[alex.freed.007@gmail.com]

On Dec 20, 7:17 am, Steven Hirsch <snhir...@gmail.com> wrote:
> Do you get the "LOADING DRIVERS" message?  If so, that indicates that the
> upload to the card was successful and that CP/M has turned around and is
> trying to read the drivers from disk

I don't get this message but I'm pretty sure the code is getting stuck
trying to load the DRIVERS file.
In the "locked" state Apple is looping waiting for a byte from z80 (in
R1Z80BYTE) and the z80 is
waiting for data from Apple. I looked at the stack and the calling
routines were outside of the BIOS.

So last night (or rather early this morning) I have disassembled the
CP/M code loaded from $DD00
and created a map looking at the BDOS source found on the net.
Together with your BIOS source
I have the full commented disassembly now. Just need time to trace it
further. I can see on a logic
analyzer  where the program is going but don' have the luxury of
setting break points on the z80 side.

If I don't find the remaining issue soon, I may add an address/data
comparator to assert WAIT or stop
the z80 clock on a match - instant hardware breakpoint!


>. The boot process is a little strange:
>
> - Apple bootstraps the CP6502 (6502 BIOS) into memory
> - Apple resets the Z80 and uploads an image of the Z80 CCP, BDOS and BIOS
> - Z80 banks out ROM and passes control to CP/M

Yes. Everything happening as planned up to this point.

> - CP/M reads the drivers file into Z80 memory, then downloads the drivers to
>    the CP65, which installs them.

This is apparently the place where a problem occurs. The string
"LOADING DRIVERS"
is not a part of the initially loaded image, so it must come from
another disk file.
Unless you mean "LOAD DRIVERS" which is present in the last few bytes
of the
image but is still not displayed.

We are getting there.

-Alex.