| The most important thing to remember about the 2090/2090a is that the
first SCSI unit is unit 3! Set your unit to LUN 0 UNIT 0 and set your
mountlist to have Unit 3 as the unit number. Then do a RES3 for the
1st two tracks (0 & 1). Build the rest of your mountlist to resemble
whatever partitions you want on your system. Mount RES3, prep RES3:
and then reboot! Mount the other partitions on the drive and then
format them. You may run into some problems. The SCSI support doesn't
remap badblocks very well. There is an upper bound on the partition
size (I don't remember what it is). If you have trouble completing the
format of the drive (won't finish the initialize disk), then back off
one cyl size on the partition and try again.
I'm not sure, but I think the SCSI will boot first (before the ST506).
One last thing, don't forget the termination pack.
TOPGUN
|
| Thanks for the input. Before I connect, I need to understand the
hardware interconnect. I see what almost appears as a 50-pin
interconnect running vertically towards the end of the module that
faces the rear of the cabinet. However, I don't know which pin is pin
1. Also, I don't know if parity is full time enabled, not enable-able,
or if it exists and can be enabled, whether a jumper and which jumper
needs to be in place.
Steve
|
| Re: -.1
� hardware interconnect. I see what almost appears as a 50-pin
� interconnect running vertically towards the end of the module that
That is the "internal" SCSI connector; it should be to the left of (and
parallel to) the DB-25 "external" SCSI connector that's also vertically
mounted and on the right edge of the board. The ST506 connectors (two
20-pin and one 34-pin) are mounted horizontally in a row at the top
edge of the board.
� faces the rear of the cabinet. However, I don't know which pin is pin
� 1. Also, I don't know if parity is full time enabled, not enable-able,
� or if it exists and can be enabled, whether a jumper and which jumper
� needs to be in place.
According to the manual ("Introduction to the Commodore Amiga 2000HD",
circa A2090a):
"Pin 1 of the connector is in the lower right corner. There will be
a small "1" marked on the board."
Hopefully your board has the "1" marker on the board. Otherwise, is
that "lower right corner" reference relative to the connector or the
board? One way to be sure is that by knowing all odd numbered pins
(except 25, which is open) and pins 20, 22, 24, 28, and 30 are ground,
you could *carefully* check with an ohmmeter for the "odd" side of the
connector. That is, the 50-pin connector is laid out in two, 25-pin
rows with all odd numbered pins in one row and even pins in the other,
ie: 1, 3, 5,...,49 / 2, 4, 6,...50. While this doesn't guarantee
knowing pin 1 from 49, it does give you excellent odds of *not*
reversing the cable and grounding all the signal pins (one more reason
for design engineers to make keyed connectors standard equipment).
After installing the cable at the controller end, you can check he
cable orientation at the drive end *before* connecting it to the drive
(again with an ohmmeter if necessary; a small paper clip works well to
make contact with the cable connector contacts). Then check the drive's
SCSI connector. If you need a ground reference on the drive, pins 2 and
3 on the drive's 4 pin power connector are ground.
Regarding parity, said manual doesn't mention a parity jumper, but the
later version of same (ala A2091 controller) has a jumper to disable
parity checking on the message-in phase (whatever that is; it gives
Seagate drives as an example of types that would require this setting),
but I believe most drives have parity enabled full-time. Check the docs
for the drive in question.
BTW, if you're still interested in a manual, you can have the one
mentioned here; I received the older manual with my A2091 equipped
A2000HD (that saga elsewhere in this conference). While it's not the
most complete manual, it may come in handy. Send me MAIL if you want it.
Pete
|