[comp.sys.apple2] More SCSI

mcl9337@harpo.tamu.edu (LOWE, MARK CHRISTOPHER) (06/23/91)

Has anyone ever made a direct-connect cable from a SCSI hard drive to the
Apple High-Speed SCSI Card DB-25?  I used a cable configuration I got out of
a book for Macs.  The cables you buy from Apple are BR-50 to DB-25's, but the
connections from the hard drive to the BR-50 are straight-through, so I
eliminated the middle-man, basically.

My question is this... I'm using system 5.0.4.  I have installed it for 
SCSI Hard Drive.  When I boot, GS/OS does not acknowledge the existence of the
drive, nor does Advanced Disk Utilities (a suggestion from Doug Gwyn).  I am
running without manuals here.  HELP!

Assuming my cable is correct, what should I be seeing when I boot the GS from
a system disk, and there is an uninitialized SCSI drive connected to the system.
Then, what should I do from that point??  The SCSI card is in slot 7.

If anyone has made such a cable as this, and I made some kind of terrible error,
PLEASE let me know... my pinouts are below:

DB-25		HD
-----		--
1		49
2		46
3		50
4		45
5		44
6		43
7		16, 18, and 19
8		26
9		20, 21, and 22
10		29
11		31
12		32
13		33
14		1, 2, and 3
15		48
16		4, 5, and 6
17		41
18		7, 8, 9, and 11
19		47
20		34
21		27
22		28
23		30
24		23, 24, and 25
25		38

		10, 12-15, 17, 35-37, 39, 40, and 42 - No connection

This represents a LOT of painstaking soldering of ribbon cables!!!  :-)
If there is something wrong here, let me know.

Thanks again...

Mark C. "Bro!" Lowe - KB5III

phs172m@vaxc.cc.monash.edu.au (Stephen Harker) (06/24/91)

In article <17679@helios.TAMU.EDU>, mcl9337@harpo.tamu.edu (LOWE, MARK CHRISTOPHER) writes:
> [Stuff re SCSI problem and pinouts deleted]
>
> This represents a LOT of painstaking soldering of ribbon cables!!!  :-)
> If there is something wrong here, let me know.
> 
	There is a recent reposting of an article by Thad Floryan in
comp.periphs.scsi listing the 25pin and 50pin SCSI pinouts.  Have a look at the
article and compare the connections you have made with the respective pinouts
to check if you have them correct.  If your site no longer has the article I
could post you a copy.  You are correct about the drive 50pin to box 50pin
cable being straight through.

	Assuming that you have the SCSI driver and manager copied from
SYSTEM.TOOLS to SYSTEM.DISK *and* have the SCSI cable pushed fully into the
drive (my mistake first time!) then Advanced Disk Utility should give you
information about a drive that is connected.  Also check that you don't have a
conflict in SCSI ID's at some point, it would not be causing your present
problems however.

-- 
Stephen Harker			phs172m@vaxc.cc.monash.edu.au
Monash University		Baloney baffles brains: Eric Frank Russell