-
Updated 2023-07-12: Hello, Guest! Welcome back, and be sure to check out this follow-up post about our outage a week or so ago.
Connect Macs via SCSI
- Thread starter agg23
- Start date
LCGuy
LC Doctor/Hot Rodder
With the exception of a PowerBook (any PowerBook with SCSI except the PowerBook 140 and PowerBook 170) in SCSI Disk Mode, you cannot connect any two Macs together via the SCSI bus...not only is it unlikely that it would work, but also, you run the risk of screwing up the SCSI bus on either machine. If you want to share files between the machines, your best bet is to set up a small network, either using LocalTalk (if its just the two machines, you don't even need LocalTalk/PhoneNET connectors, a standard serial cable, like the one used to connect a Mac to a printer will do) or ethernet.
johnklos
Well-known member
Some file sharing schemes did work this way, but they were primarily used for sharing video editing files. Most fibre channel SCSI works this way.
On Macs, though, you need a SCSI card which will let you change the SCSI ID of the controller itself in at least one of the machines, then you need software which "locks" the drive for all but one of the machines (or you can write everything to the drive with one system, make it read-only, then let both read it). Transoft was one suite of software which did this, as did Avid's old file sharing (I don't remember the name of their stuff right now).
It has it's place, but it's a very limited place.
On Macs, though, you need a SCSI card which will let you change the SCSI ID of the controller itself in at least one of the machines, then you need software which "locks" the drive for all but one of the machines (or you can write everything to the drive with one system, make it read-only, then let both read it). Transoft was one suite of software which did this, as did Avid's old file sharing (I don't remember the name of their stuff right now).
It has it's place, but it's a very limited place.
Trash80toHP_Mini
NIGHT STALKER
Interestingly enough, it WAS possible to share files with a PC, back in the day, by using a product called QuickShare. The, then fairly rare, 8 bit ISA SCSI Interface Card was hardwired as SCSI 6, IIRC, and required that it be on the very end of the SCSI Chain, having termination resistor packs installed right on the Card's PCB.
I managed to talk my way into a dealer's price for this product, as well as the (appropriately enough [
] ]'> ) JT-FAX Card, one of the first 8 bit ISA FAX cards!
QuickShare was awesome, my SE/20 transferred files with the PC at 8 MegaBytes/sec w/no network handshaking overhead. I also had 20 of the 40 MB of the MFM HDD in the PC formatted as a Mac partition (it actually looked like one big file to the PC) and was able to backup the SE to the PC!
I had customers FAX their artwork to me, translated the PCX files to PICT, IIRC, and then pasted them into Fontographer to digitize as a character in a Type 3 Font, then I'd copy/paste that character into another character and then cut/ paste four postscript outlines at a time into however many characters I needed that contained a bounding box. MacSignmaker could then import the Type 3 Postscript Font (5 outlines per character) and convert it into their own polyline font format. Then I'd type in all the characters necessary to rebuild the entire piece of artwork, delete all the bounding boxes and then scale and output directly to the Vinyl Cutting Plotter.
Using a hand held scanner (having graduated from ThunderScan when prices came down) and my paperless FAX->Vinyl system, I was creating and cutting PostScript Graphics a full year ahead of all the competition in NYC!
SWEET! [] ]'>
I managed to talk my way into a dealer's price for this product, as well as the (appropriately enough [
] ]'> ) JT-FAX Card, one of the first 8 bit ISA FAX cards!QuickShare was awesome, my SE/20 transferred files with the PC at 8 MegaBytes/sec w/no network handshaking overhead. I also had 20 of the 40 MB of the MFM HDD in the PC formatted as a Mac partition (it actually looked like one big file to the PC) and was able to backup the SE to the PC!
I had customers FAX their artwork to me, translated the PCX files to PICT, IIRC, and then pasted them into Fontographer to digitize as a character in a Type 3 Font, then I'd copy/paste that character into another character and then cut/ paste four postscript outlines at a time into however many characters I needed that contained a bounding box. MacSignmaker could then import the Type 3 Postscript Font (5 outlines per character) and convert it into their own polyline font format. Then I'd type in all the characters necessary to rebuild the entire piece of artwork, delete all the bounding boxes and then scale and output directly to the Vinyl Cutting Plotter.
Using a hand held scanner (having graduated from ThunderScan when prices came down) and my paperless FAX->Vinyl system, I was creating and cutting PostScript Graphics a full year ahead of all the competition in NYC!
SWEET! [
] ]'>The official answer to the original question is "no, you can't connect two desktop Macs via SCSI". This is because both Macs have their internal hard drives set to SCSI ID 0 and their SCSI controllers set to ID 7, hence there will be ID conflicts.
However, it is possible and I used to routinely connect Macs together when upgrading customers to new machines. It was much easier to carry a single SCSI cable and a SCSI ID jumper than an external hard drive case + SCSI cable + power cord when on site.
The work around goes like this:
- open the Mac that is to act as an external hard drive. Jumper the SCSI ID to 1 (or whatever, just not 0 or 7). On many Macs (especially LCs), this can be done by just unclipping the drive and swinging it up to access the ID pins - no need to unscrew anything, or even unplug the cables.
- connect the two computers using a 25 way to 25 way SCSI cable.
- Power on the "external hard drive" Mac and press the programmer's interrupt button during the RAM test (the gray checkerboard screen before the Mac "smiles")
- This Mac then "crashes" prior to its SCSI controller being initialised on SCSI ID 7 and is to all intents and purposes an external SCSI disk.
- Boot the other Mac and tranfer data across.
However, it is possible and I used to routinely connect Macs together when upgrading customers to new machines. It was much easier to carry a single SCSI cable and a SCSI ID jumper than an external hard drive case + SCSI cable + power cord when on site.
The work around goes like this:
- open the Mac that is to act as an external hard drive. Jumper the SCSI ID to 1 (or whatever, just not 0 or 7). On many Macs (especially LCs), this can be done by just unclipping the drive and swinging it up to access the ID pins - no need to unscrew anything, or even unplug the cables.
- connect the two computers using a 25 way to 25 way SCSI cable.
- Power on the "external hard drive" Mac and press the programmer's interrupt button during the RAM test (the gray checkerboard screen before the Mac "smiles")
- This Mac then "crashes" prior to its SCSI controller being initialised on SCSI ID 7 and is to all intents and purposes an external SCSI disk.
- Boot the other Mac and tranfer data across.
ClassicHasClass
Well-known member
On the IIci, you can also pull the J1 jumper off for a similar effect. That essentially lobotomizes the IIci and turns it into a big overgrown SCSI enclosure. Power down and put the jumper back on when you're done.
Mike Richardson
Banned
I remember hooking up a 6500 to a 6100 one time and it worked - the 6100's hard drive showed up on the 6500.
Since the 6500 doesn't use a SCSI hard disk, it had nothing on ID 0. I turned on the 6500 first, waited a few seconds, then turned on the 6100, which was headless.
I guess what happened is that the 6500 got control of ID 7 first, and when the 6100 tried to take it, it failed and crashed silently, but allowed the internal SCSI hard drive to pass through.
Since the 6500 doesn't use a SCSI hard disk, it had nothing on ID 0. I turned on the 6500 first, waited a few seconds, then turned on the 6100, which was headless.
I guess what happened is that the 6500 got control of ID 7 first, and when the 6100 tried to take it, it failed and crashed silently, but allowed the internal SCSI hard drive to pass through.
noidentity
Well-known member
Just a note, when you do set up a PowerBook to act like an external SCSI device, it'll show a SCSI icon on screen to confirm it's in slave mode. I think it's the cable itself that tells the PowerBook to go into slave mode, as you use a special cable/adaptor that has a female SCSI connector on it, just as an external hard drive would.
jwmcfarlin
Well-known member
I came across this thread and thought I'd post my question here. I have an (extra) PB1400c with a 2GB hard drive that I have connected to my IIci for the purposes of establishing a direct mode connection and availing myself of the 2GB volume on the PB1400c. Given that the volume is (only) 2GB, and formatted as MAC OS Standard, I see no reason that a IICi running 7.6.1 would tell me that it cannot access it because it is a large partition or not mount it. I have correctly set the SCSI address as 2, which is unused by the IIci, and password protection is off.
Has anyone else used a 1400 in disk mode and come across difficulties?
Best,
John
Has anyone else used a 1400 in disk mode and come across difficulties?
Best,
John
ClassicHasClass
Well-known member
Is the 1400 drive formatted as HFS or HFS+?
jwmcfarlin
Well-known member
HFS. The drive was formatted from the 7.6.1 install disk.
I figured out what it was. The deal is this: You actually can't mount a 2GB drive on a Mac IIci. I don't know whether it's a IIci/68030-specific limitation or whether HFS just peters out just shy of 2GB due to address limits (I am guessing the former). I resorted to splitting the 2GB drive into two 1GB partitions and they mounted just fine. It's not precisely what I wanted, but it gets the job done.
Best,
John
P.S.: For search engine tag purposes: Direct Drive Mac IIci Powerbook 1400
I figured out what it was. The deal is this: You actually can't mount a 2GB drive on a Mac IIci. I don't know whether it's a IIci/68030-specific limitation or whether HFS just peters out just shy of 2GB due to address limits (I am guessing the former). I resorted to splitting the 2GB drive into two 1GB partitions and they mounted just fine. It's not precisely what I wanted, but it gets the job done.
Best,
John
P.S.: For search engine tag purposes: Direct Drive Mac IIci Powerbook 1400
jwmcfarlin
Well-known member
Gah. Something else.
Don't let the IIci see your SCSI Disk Mode laptop with a PCMCIA card inserted with a CF card that counts as a large volume (2GB and up). It will render your Powerbook's drives unreadable to the IIci and force a reinitialization and OS install (actually--you don't have to have an OS on a drive for it to be seen by a desktop Mac). Not a huge task if you have the tools, but a hassle. Upside is that I learned something and from now on will be careful about what's in the PCMCIA slots when I connect in SCSI disk mode.
Best,
John
Don't let the IIci see your SCSI Disk Mode laptop with a PCMCIA card inserted with a CF card that counts as a large volume (2GB and up). It will render your Powerbook's drives unreadable to the IIci and force a reinitialization and OS install (actually--you don't have to have an OS on a drive for it to be seen by a desktop Mac). Not a huge task if you have the tools, but a hassle. Upside is that I learned something and from now on will be careful about what's in the PCMCIA slots when I connect in SCSI disk mode.
Best,
John
jwmcfarlin
Well-known member
:lol:
I seem to be screwing it up by the numbers here...
I had installed OS 8.5 on my PB1400c, and afterwards powered down and set up the SCSI direct mode hookup. Bam. Both drives were visible on my IIci when connected via SCSI in disk mode.
"All's well, so okay time to go ahead and put the 8.6 upgrade on" I think and so I do it and power down and hook it up and fire up the Macs as they're supposed to be fired up.
The drives did not appear on the desktop of the IIci when connected via SCSI.
So, perhaps 8.6 caused a problem of some sort...I don't particularly mind if I have to run 7.6.1 or 8.5 as the PB1400c that's sitting on top of my IIci is just an external hard drive and a way (with some fiddling with it) to get larger files from the wider world to it...
Best,
John
Posted from a PB1400c/G3 250 wirelessly
I seem to be screwing it up by the numbers here...
I had installed OS 8.5 on my PB1400c, and afterwards powered down and set up the SCSI direct mode hookup. Bam. Both drives were visible on my IIci when connected via SCSI in disk mode.
"All's well, so okay time to go ahead and put the 8.6 upgrade on" I think and so I do it and power down and hook it up and fire up the Macs as they're supposed to be fired up.
The drives did not appear on the desktop of the IIci when connected via SCSI.
So, perhaps 8.6 caused a problem of some sort...I don't particularly mind if I have to run 7.6.1 or 8.5 as the PB1400c that's sitting on top of my IIci is just an external hard drive and a way (with some fiddling with it) to get larger files from the wider world to it...
Best,
John
Posted from a PB1400c/G3 250 wirelessly
jwmcfarlin
Well-known member
Heh. But you CAN boot a PowerBook 1400c in 8.6 from a PCMCIA card and it won't affect the IIci from seeing the drives later on when you connect via SCSI. I'm learning something every day, it looks like.
Best,
John
Best,
John
Similar threads
