[comp.periphs.scsi] ACB-4000A help!?!?!?

ekalenda@cup.portal.com (Edward John Kalenda) (04/15/91)

I have an AST 4000 disk/tape unit for which I have no docs. The disk
works as SCSI unit 0 but I would like to have it be unit 1. If
anybody out there has docs on the ACB-4000A, I'd appreciate help with
the following questions. Before you say to call Adaptec, I've already
done so without ever getting to talk to anybody but the receptionist
and several voice mail machines.

Can the card support a second drive?
How does the card know the disk parameters (heads, cylinders, etc.)?
What is the function of the jumper block that looks like this?

	O M K I G E C A
	: : : : : : : : J5
	P N L J H F D B

How about the jumper near J1:

		R
	    PU     S
		T

How do I remove the onboard termination? I presume it is the resistor
packs labelled RP4 and RP3 since they are socketed.

The disk is a Fujitsu M2243AS. Anybody know what the switch pack and
four jumper blocks do?

Always searching for more disk space at minimal cost,
Ed
ekalenda@cup.portal.com

fortinp@bwdls56.bnr.ca (Pierre Fortin) (04/16/91)

In article <41277@cup.portal.com>, ekalenda@cup.portal.com (Edward John Kalenda) writes:
> I have an AST 4000 disk/tape unit for which I have no docs. The disk
> works as SCSI unit 0 but I would like to have it be unit 1. If
> anybody out there has docs on the ACB-4000A, I'd appreciate help with
> the following questions. Before you say to call Adaptec, I've already
> done so without ever getting to talk to anybody but the receptionist
> and several voice mail machines.
> 
> Can the card support a second drive?

Yes.  I have two 4000A controllers online with 2 drives on the first and 1 
drive on the second.  You need to daisy-chain the 34-pin connector to both
drives, and a separate 20-pin cable from J1 to drive 1.

> How does the card know the disk parameters (heads, cylinders, etc.)?

This is a drive issue, not a controller issue in this case.

> What is the function of the jumper block that looks like this?
> 
> 	O M K I G E C A
> 	: : : : : : : : J5
> 	P N L J H F D B
                      ^ LSB of controller address
                    ^
                  ^     MSB of controller address
                ^       DMA transfer rate (max rate with no jumper)
              ^         extended command set (when replacing SASI controllers)
            ^           not used
          ^             install jumper to support drives that drop SEEK
                        COMPLETE line on the ST506/412 interface during
                        head switches.
        ^               jumper enables self-diagnostics


> 
> How about the jumper near J1:
> 
> 		R
> 	    PU     S
> 		T

These jumpers are used to select the write pre-comp for the two connected
drives.  It overrides MODE SELECT software selections.  Pre-comp is 12ns.
R-PU:  no pre-comp
R-S:   pre-comp starts at same cylinder as reduced write current (both drives)
R-T:   pre-comp all tracks (both drives)

> 
> How do I remove the onboard termination? I presume it is the resistor
> packs labelled RP4 and RP3 since they are socketed.

If this is the only controller, do not remove these terminators; otherwise, 
remove them on all but the last controller on the SCSI chain (except if using
an external terminator; in this case remove all controller terminators).

> 
> The disk is a Fujitsu M2243AS. Anybody know what the switch pack and
> four jumper blocks do?

Nope... sorry.

> 
> Always searching for more disk space at minimal cost,
> Ed
> ekalenda@cup.portal.com


Cheers,                      
Pierre Fortin       fortinp@bnr.ca         (613)763-2598

csbrod@immd4.informatik.uni-erlangen.de (Claus Brod) (04/16/91)

ekalenda@cup.portal.com (Edward John Kalenda) writes:

>I have an AST 4000 disk/tape unit for which I have no docs. The disk
>works as SCSI unit 0 but I would like to have it be unit 1. If
>anybody out there has docs on the ACB-4000A, I'd appreciate help with
>the following questions. Before you say to call Adaptec, I've already

>Can the card support a second drive?

It does that very well. Just use the second 20-pin-connector
on the controller board for the second ST506 drive (data bus;
the control bus is shared).

>How does the card know the disk parameters (heads, cylinders, etc.)?

It reads them from disk. To be able to do that, the drive must be
formatted once with an Adaptec 4000A. Doing this initial format,
you need to tell the Adaptec the drive parameters once via the
Mode Select command.

>What is the function of the jumper block that looks like this?

>	O M K I G E C A
>	: : : : : : : : J5
>	P N L J H F D B

The three jumpers A-B, C-D, E-F are for selecting the SCSI target
number which answers your first question. The other jumpers
aren't that important, but I can find that out for you if you
like.

>How about the jumper near J1:

>		R
>	    PU     S
>		T

This jumper is for selecting the write-precompensation mode.
In most cases, you won't have to fiddle around with it.

----------------------------------------------------------------------
Claus Brod, Am Felsenkeller 2,			Things. Take. Time.
D-8772 Marktheidenfeld, West Germany		(Piet Hein)
csbrod@medusa.informatik.uni-erlangen.de
Claus Brod@wue.maus.de
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