[MoontaMacman]

I have been given the task of putting together a working unit from 5 old CPUs for a friend- I can get the basic unit up and running OK but I thought to maximise the unit I would fill up all the RAM slots - taking from the unused CPUs and also put two hard drives in place - physically a piece of cake as they say but I cannot work out how to designate master and slave- cannot find anywhere to set hard drive ID - with either hard drive in place it works but when I put both in it just sits there at boot up and looks forever - I know it is because both are probalby master status ( '0' location) but I cannot recall how to change the settings

Any help would be appreciated- I figure so long as the spare drives are there it would be good to use them- I hope to get two CPUs up eventually but at present only have one mouse and one monitor (well I have a second monitor but no cable)

These units were part of a cargo container load full of old Macs that were going to be tossed out -- break your heart to see such lovely old machines trashed

Ron [email protected]

[druber]

Ah SCSI, can never get tired of those conflicts. Yes, both drives are probably set to "0". There should be a set of pins on the back of the drive, next to the SCSI cable plug-in. There's probably a tiny plastic jumper in the first position. Move it to, say, the second. Been a long time since I've done this, but there may even be a sticker on the drive that tells which pin set goes with which SCSI id. Give it a whirl, that might do it.

[MoontaMacman]

Thanks druber ,

I located the "pins" - a set of seven pins on the underside front of the drive (it is an IBM DPES 31080 - 1 Gb) and also did some more searches for info -I found a schematic which shows the various combinations of the first 3 pins which set ID 0, 1 or 2 but the fool of a thing does not know that :-))

I reversed postions -top to bottom just in case also - tried to start up from Nortons or an OS disc but when the two drives are in it just hangs there forever - not to worry I'll keep at it - sooner or later the SCSI gremlins will get tired and let me succeed- I hope :-)

I am reluctant to reformat - not sure that would help anyway- there is an OS on each drive (8.0 on one 8.5 on the other)

As I remember it ID 0 is the dominant drive and the others can be slave but the problem is even after resetting pins they each come up as IS 0 when used independently- confusing that - although it may be that any single hard drive assumes the ID of ID 0

ah the fun of SCSI

Funny aside story - I rang up an apple dealer and spoke to the techs- the first one assured me that he was only familiar with things after 1998 but another tech might know more as "he is twice as old" -- but even he seemed to know no more than I do- it's a worry for old Mac owners- keep those manuals folks !

made me feel positively ancient - which is fair enough I guess - I am

thanks again
Ron

[DrBoar]

SCSI has no slaves nor masters.
The first 3 pairs of often callad A2, A1 , AO give the SCSI number 4,2,1
So "0" is no jumpers, 000
"1" is a jumper at A0, 00X
5 is then X0X jumpers (4 plus 1)
Other pins has other purposes on the 31080 is is the 6 pair that handles termination. In theory only the last item in the SCSI chain should be terminated, however most of the time it works to have the termination on on all devices in my experience. If that does not work try removing the termination jumper that is the last physical drive on the chain. Dont mess with jumpers 4, 5 and 7.

the SCSI numbering is not that important. If there is no informatiion of booting disk in the PRAM the computer will look for an OS in the order floppy=>CDdrive=>SCSI 0, SCSI 1, SCSI 2...

The CD usually is SCSI 3 so set up the disks as O, 1 or 2 that is jumpers 000,
X00 or 0X0. Any SCSI id is equally bootable.

I had my old 7200 (now with a 7600 motherboard) two internal HDs, the CD drive, SCSI scanner and two or 3 external HDs, then it is pretty full

[druber]

And thank you DrBoar. I've actually had some similar problems with an old Umax J700, though I think the problem goes deeper than SCSI. It had been my main computer for a long time. 6 months ago, or so, I hooked it up to the network and ran Software Update. All it downloaded was the lastest CarbonLib. And since then it's been dead dead dead. Can't even get it to start up from the original CD that came with the machine. I do have some data on there I'd like to retrieve, but at the moment I've given the machine up as lost. Tried starting up from a different hard drive, and sometimes it will actually boot. But with both drives hooked up, nothin doin. And without an extra monitor, I'm not quite interested enough to mess with it. Any thoughts?

[MoontaMacman]

Thank you Dr Boar -- I tried every combination of the first three pins last night - none worked - then this morning on reading your message I tried terminating pin 6 -- and it fired up - at last !

To quote Maxwell Smart - "The old termination trick" - ah yes!

Now the only problem i have is parting with these little gems and giving them back to the owner - oh yes I have some items in the Trash I cannot delete- either "they are in use " (an empty folder!) - -or "they cannot be found" - only a minor nuisance but I'd like to get rid of them - I tried holding down Control -- Option-- and Command with the Empty trash command (one at a time not all together - I cannot remember which one was supposed to work) but it refuses to go

Amazing world isn't it ? Here I am in South Australia and I get help from folks in Sweden and East Africa as easily as if you were my neighbours - which I wish we all saw is what we are

many thanks

Ron

[MoontaMacman]

Just back from delivering the goods to the happy owner - set the 7200 up with two drives - installed a swag of shareware and generally tidied things up - cleaned off and reinstalled OS etc- - works like a charm and should keep her visitors (daughter and grandchildren) happy for many hours --she wanted one for them to use to keep them off her own machine - I didn't set it up for the internet although all the software is there so if -- but not unless they request it..

now if I can find a monitor cable I can get another unit set up for another old lady I know - I hate to see such beautiful machines go to the tip when a little work can bring them up like new

thanks for the help

Ron