Compupro progress / Console questions ?

[Dave Dunfield]

Hi Allison,

>known but forgotton problem in the 8" world.  765 has a READY sense line
>and the 851 is know for changing state of the line during select.
>Solution, force ready at the board (jumper) and don't use it. READY
>was for detecting disk changes.

Tried forcing READY on the original SA-851's, and it still didn't boot.
I immagine there must be some other jumpering issues. I'm leaving that
for now, as I do have a drive working.


>>According to Compupro Docs, the Console port is USER 7 - I have
>>setup the board to respond to users 4-7, which is the default setup
>>requireed for the console shows in the Compupro docs. As noted
>>above, I can select user7 and talk to the console correctly, which
>>would suggest that this is all working correctly.
>
>It is likely initing the ports but may not use any of them.  It's 
>possible the bootable media may use a different port scheme.  Its
>likely a difference between the boot roms and the BIOS code once
>the boot transfers to the OS.

Yes, thats one of the possibilities - others are that it is hanging
on some other part of the init, or simply crashing (bad RAM etc.)


>I assume based on the CPU your runnig CP/m-86 (or any DRI -86)
>as the boot roms load a loader then load the OS (bios and all).
>So booting is multi step code.

Yes, it is CP/M 86 as noted in my original message:

>The disks I am using are original Compupro distribution disks
>(Can't make copies yet), labled:
>
>Serial# C86-272-1854
>Version: CP/< 86 (P0 in handwriting)
>CP/M 86 1.1
>SYSTEM MASTER
>Disk Number 1
>Single Sided - 1024 B/S
>
>Serial# C86-0272-1854
>Version: 1R
>CP/M 86
>SYSTEM MASTER
>Disk Number 2 of 2
>Single Sided - 1024 B/S

I was hoping someone might recognize these disks and be able to tell me
if they are setup for the Interfacer-4, or some other device - or perhaps
someone has a known good boot disk for this config (86/87, Disk1A,
Interfacer4)?

I've had to put it away to get some other more pressing items on the bench,
however when I get back to it, I am going to proceed as follows:

I've been using an EPROM emulator to load my modified boot - this will also
let me change the content of the boot ROM with power-on (while it is switched
out of course).

The boot rom provides 512 bytes at 00-FF - while it is enabled (out of reset)
I can write all of memory, however I can read only the boot ROM - once I hit
the enable, the boot-rom disappears and RAM appears.

I plan to write a loader which will allow me to load a block of code into
RAM at $0200, and to switch the ROM OFF and the RAM ON in the very last
instruction of the 0000-01FF block - so it should transition to the code in
RAM correctly.

Boot the system normally,
then load the loader into the boot-rom (via EPROM emulator),
Reset should start loader.
Send my 8086 monitor.
Loader will put it in RAM and transition to it.
Then I should be able to browse around the loaded memory image,
and perhaps determine what type of console device it wants to communicate
with.

Main problem is: I don't know much about CP/M-86 - I do not have technical
documentation or experience with it.

With CP/M-80, it's fairly easy to find the console drivers by following
addresses. I have no idea how to do this with CP/M-86

Can you give me any pointers to how to find the console I/O functions under
CP/M-86?

I do have CP/M-86 running on an APC that I Can experiement with - I will also
check the APC docs to see if they contain any useful info. I also have a Rainbow
and docs, however I do not know how similar it will be as I seem to recall that
the CP/M it has is a special dual-processor version.

As always, thoughts, ideas, suggestions etc. are welcome.

Regards,
Dave

-- 
dave04a (at)    Dave Dunfield
dunfield (dot)  Firmware development services & tools: www.dunfield.com
com             Collector of vintage computing equipment:
                http://www.parse.com/~ddunfield/museum/index.html