bill@ssbn.UUCP (05/27/87)
This is a long article, that's why I didn't post it before but I got
four requests for the information within two days of my posting the
offer to help with hard disk drives for the PC 6300 PLUS. Note that
the controller settings are for a Western Digital controller, I don't
know about any others (the AT&T is, I understand, a WD 1002).
The PC 6300 PLUS Hardware Reference Manual mentions the following hard disk
drives:
Manufacturer Formatted Model Cyls Heads
Capacity
Various 10Mb ST-412 306 4 (Generic 10Mb drive)
CDC 30Mb Wren 697 5 (Half height)
CMI 20Mb CM6426 640 4 (Original PC/AT drive)
Tandon 40Mb 981 5
Seagate 40Mb ST-4051 977 5
Seagate 20Mb ST-225 612 4 (Generic 20Mb drive)
Miniscribe 80Mb 6086 1024 8
Micropolis 67Mb 1325 1024 8
There is one motherboard switch and two controller jumpers for drive type
select, thus the eight possibilities. It is possible that the autoconfig
WD controller might record drive information on the drive in some strategic
spot that the motherboard BIOS could use but the documentation is silent
on that point.
Settings for memory and ST-4051 disk drive(s) on a PC6300 PLUS.
Motherboard switches:
1 2 3 4 5 6 7 8
DSW1 On Off Off Off On Off Off On
DSW2 Off Off On Off Off On On Off
Those mean as follows: DSW1 1&2 96tpi A, 48tpi B; 3&4 Seagate drive (20 or 40)
5&6 80x25 mono; 7&8 two floppies
DSW2 1-4 256K chips 1M stuffed; 5 No 80287; 6 Mfg test
7 use MB wini BIOS; 8 16K EPROM BIOS
Memory board switches (I have 2 for 5Mb total):
1 2 3 4 5 6 7 8
SW1 On On On On Off On Off On
SW2 On On Off Off Off Off Off Off
Second 2M board
SW1 On On Off On Off On Off On
SW2 On Off Off Off Off Off Off Off
Controller jumpers (BIOS EPROM P/N 62-0000 42-xxx *NOT* 62-0000 43-xxx):
W1 1-2
W2 1-2
W3 Open (Disables BIOS ROM)
W4 2-3
W5 1-2
W6 2-3
W7 1-2
Switch 1 (Dip plug at rear of board)
3-4 Closed (Drive 0 is ST-4051, Open for ST-225)
1-2 Closed (Drive 1 is ST-4051, Open for ST-225) Yes, you can mix
Note that the above settings differ in one way or another with the RAM board,
computer, or Hardware Ref. These are correct, the docs are not.
Here's the ceremony to bring it up.
Boot DOS from floppy, go into DEBUG for low level format (DEBUG is on disk 2)
A>DEBUG
-R AX (Set up AH=Drive, AL=Interleave, drive zero shown)
:0003
-G=F000:C038 (Enters the Motherboard BIOS formatter)
Formatter signs on and natters at you saying it's going to do drive zero
with an interleave of 3, inviting you to press "y" to proceed, you answer
y
Format complete or error code, they are:
01 Bad Command, 02 Address mark not found, 04 Sector not found, 05 Reset failed
07 Set parameters failed, 09 Attempt to DMA across 64K boundary, 10 Data error
11 ECC error corrected, 20 Controller failure, 40 Seek failure, 80 Time out
BB Undefined error, FF Read status failed
Errors coming out of low level format are usually a cabling problem.
I wanted a small (5Mb) DOS only partition, so I did a DOS FDISK and made a
DOS partition (NOT active, not bootable) on cylinders 1-125 (On the 4051)
DO NOT let it start at cylinder 000. On the second drive (100% merged) you
must make an active partition for Unix and it MUST start on 000. After FDISK
(still in DOS) I formatted the DOS partition, put in the foundation set disk
and RESET. The installation then proceeds normally, but there are some details
that you might want to know about.
Diskette 1 of 7 is a Unix file system diskette. To look at it you must mount
it read only (mount will fail because it's write protected otherwise). You
can look at the others with cpio or cpiopc. As shipped, the system checks for
the state of the disk with as program called fsstat. If a non-zero returns,
fsck will be run automatically with all output to /dev/null and YES to all
questions. To change that, edit the /etc/bcheckrc script for bootup and
/etc/fsanck for shutdown. For the second drive you will also have to edit the
/etc/checklist and /etc/fstab for the additional file system(s). Mine are
below FYI
My /etc/checklist
/dev/root
/dev/rdsk/1s1
/dev/rdsk/1s2
/dev/rdsk/1s3
/dev/rdsk/1s4
My /etc/fstab
/dev/dsk/1s1 /usr/lbin
/dev/dsk/1s2 /usr/spool
/dev/dsk/1s3 /osm
/dev/dsk/1s4 /usr/src
As you can see, I have /usr/lbin as the first 215 cylinders of drive 1,
/usr/spool as the next 500 cylinders, /osm as the next 30 cylinders and
/usr/src as the last 215 cylinders. That's a carry over from the ST-412
mentality when it was good to distribute the seeks across two physical
drives to improve performance. I can't say that it buys me anything with
4051's, but if you are going to use a 225 as drive 1, it might. Also note
that I run fsck against the "raw" disk, it's faster (and somebody said to
do it). When you format the second drive you must use slices if you want
more than one file system.
--
Bill Kennedy {cbosgd | ihnp4!petro | sun!texsun!rrm}!ssbn!bill