Ampro Little Board questions...

From: ajp166 <ajp166_at_bellatlantic.net>
Date: Sat Dec 15 22:47:20 2001

>> > From: Gene Buckle <geneb_at_deltasoft.com>
>> Funny, the Ampro docs list all these various controllers and whatnot.
>> The software also _asks_ what controller it is going to talk to. The
>> SCSI controller is part of the LB. What would the software consider
the
>> onboard controller to be?


NCR5380! But that's half the picture. The other half is the SCSI
controller on the other end of the cable. What I meant by PC logic
is that in PCs you plug in an adaptec controller or whoever and you
need a driver specific to that controller. The AMPRO-LB has the
onboard NCR5380 which is the controller and the software specific
to that is in both the bootrom and CP/M bios.

The other peice of that that does not conform to the PC standard
is the other end of the 50pin SCSI cable is the "drive" and back then
the drive was MFM (ST225 typically) with a Bridge adaptor to go
from SCSI to MFM and that could be done with a board made by
Xybec, Adaptec or Western Digital. Now, those bridge boards did
not behave exactly the same like modern SCSI drives so the "driver"
had an install/init that tweeked the CP/M bios to conform as well as
partition the disk for CP/M use. The CP/M Bios (and bootrom for
that fact) do not query the drive for it's config like PCs. It must be
hard coded into tables in the bios. The bridge controllers require
this info to be pushed into them before they can access the
physical drive. This is in contrast to SCSI drives that have the
tables integral to themselves.

FYI: CP/M supported only 8mb per logical drive so a ST225(20mb)
was usually partitioned into three logical drives (for ampro that would
be A, C and D). Drive B is reserved for floppy as is pseudo drive E.
Drive A(physical drive 0) is always the bootable drive and can be
either floppy or hard disk. The tables for logicla drives are limited
to 16 logical drives (A through P) by CP/M itself and if memory
serves only 10 logical hard disk partitions in the Ampro HD
CP/M bios. So any drive larger than 80mb cannot be fully
accessed. There are ways around the latter problem but
that's a different issue.

>What hard-drive are you using? If it is a SCSI drive? Is it set to
>ID=0? If so, choose either Seagate or Maxtor and give that a try.


I used a 45mb fujitsu. The boot roms expect it to be ID=0.

>> > formatting. If you dont mind hacking Z80 code you can go frm
>> > an AMPRO LB with SCSI to a smaller SCSI drive (64mb or less,
>> > or the rest will be unused).
>>
>> I've got a 20MB SCSI drive I'm trying to use. The bootrom rev tells
me
>> that it's got support for the SCSI controller. What coding has to be
>> done?


CP/M bios which is not the boot rom. The reason for that is the Drive
tables and the controller tables in the install(HDINIT) and format(HDFMT)
will not work for all but a limited subset of possible drive/controller
setups.
The only SCSI drive directly supported was the ST157N and maybe the
ST296N might work.

>If you have the proper version of the HD Utilities, you should not need
>to do any.
> - don


Only if you have a supported controller and drive, otherwise they
do not help you much.


Allison
Received on Sat Dec 15 2001 - 22:47:20 GMT