I have two scanners that need to run on MAC G4 with OS 9.2.2. They both run fine individually through an Adaptec 2906 SCSI PCI card. However, when chained, the two scanner don't appear to like each other.
OK, I have two open PCI slots on my MAC G4 Quicksilver. Could I simply install a second Adaptec 2906 SCSI card and connect each of the scanners to its own card? My intuition suggests that this should work, but ????
Any SCSI experts out there?
Sandy King
Absolutetly. You would then have separate SCSI buses, basically separate loops. Then the only other issue to be careful about would be software conflicts, though you can usually get around that. If either scanner needs to be initialized at start-up, like through an extension, that would be one potential conflict, even with separate SCSI buses. In other words, you would eliminate a hardware conflict, though potentially still have a software conflict. If you have the ability to only load the driver when needed, that is one work-around.
I have run such a set-up many times in the past. The worst case was several devices that did not like each other; though having them connected and not powered on solved some problems; each device only got powered on as needed.
Ciao!
Gordon Moat
A G Studio
Gordon,
Thanks very much for this response. Just what I was hoping to hear.
Just wondering, would there be any way to have two different 2906 drivers and dedicate each to a different hardware card?
Sandy
Originally Posted by Gordon Moat
I seem to recall some SCSI manager software, possibly Lacie or Adaptec. Basically, the software allowed switching or loading of separate devices. I am not at my office at the moment, so I don't have my OS 9.2.2 machine to check. One software I do have on that is SilverLining Pro, from Lacie, though that might only allow control over harddrives . . . it might allow bus control. Maybe surf the Lacie website, or contact their tech support.
Ciao!
Gordon Moat
A G Studio
Sandy,
To make it all work now, without buying anything, you'll likely have to restart the Mac with which ever scanner you want to use already powered on to change the scanner that you are using. You can likely leave both scanners physically connected and start the Mac with only the one you want to use powered on. (you may have already discovered this) In some implementations of scsi you could hot switch and some of those switching devices and software might work on some devices like hard drives but generally scanners don't like that stuff.
Adding another pci card for a completely separate scsi bus will likely let you use both scanners powered on without scsi bus conflicts. There is some voodoo involved in scsi, so unless you test a particular configuration don't assume it will work.
If you need any, I have a lot of high quality scsi cables here and probably the Adaptec control panel that lets you run the cards. The other thing you might want scsi management is called SCSI Probe. It might run on OS 9 and might not, I don't remember now. It could have been an older system control panel.
I picked up another 2906 card on ebay so I will see how the two cards work together. If this allows me to work with both scanners powered on at the same time that is all I need. But as you suggest, there sure appears to be a bit of voodoo involved in SCSI, especially when it comes to scanners.
I have plenty of SCSI cables, though they never appear to be quite long enough!! Or be of the same type.
Sandy King
Make sure your termination is in order on each end of the last device on the chain and at the host card or whatever is powering the SCSI chain.
I have SCSI Probe working just fine on my 2000 Pismo Powerbook in OS 9.2.2. I use the SlimSCSI 1480 PCMCIA card. However, the card gets hot and makes the system lock up after a while when in sleep mode.
As Tim suggested, checking termination and ID's is a good start : they do have different ID #'s, yes? and you removed the termination from the middle one when adding the second in the chain, right? SCSI was great in its time (still is for some things) but ID conflicts and termination were the main issues I recall from when it first came along!
Andy
Andy,
Yes, I verified the termination issue and SCSI ID numbers, but one of the scanners is very sensitive to being on the chain with the other. So I decided that the best thing was to just put it on another loop, and in fact use it from another OS9.2.2 system on another partition. The issue may be more extension conflicts than a SCSI conflict since I had to also remove a handful of offending extensions that were causing one of the scanners to misbehave.
Sandy King
Sandy, I still have my twin G4 chugging along when I scan, but it's a fairly simple system (I remember extensions and Conflict Manager Ugh!) - I wasn't sure how far back your experience went. Like Henry I have a cupboard full of SCSI stuff.
So your second Adaptec, second system partition approach is working? Kind of like two different computer systems in one box!
Andy
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