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Target mode on pb100 / hdi30

Cedsrepairs

Well-known member
Okay I feel I'm entering a sub sub niche here, but anyway :)

I'm trying to understand how "target mode" works and trying to access my Powerbook 100's disk (which is a 2,5" blueSCSI) thru the proper HDI30 dock cable

I've got all that is necessary
- a beautiful Powerbook G3 PDQ, with HDI30 cable
- an even more beautiful fully restored powerbook 100
This is connected in this way
PDQ ---> hdi30 -> db25 -> scsi/dock hid30 adapter --> PB100

Whenever I put the DOCK switch on the adapter on, the PB100 immediately boot in target mode (I mean I don't need to hit "t" key), this is not supposed to happen. It is displaying a scsi logo with a number in it, the number that you configure in the control panel

If I boot my PDQ at this stage, it always tries to boot... from the PB100 (?) which obviously does not work (funny error message from System 7.0.1 telling my hardware is not supported)
This happens if I put the DOCK switch on... or OFF ! It does not care, even in plain SCSI mode, the pdq tries to boot from scsi first
Also it doesn't care the scsi ID, it seem to boot from the first bootable SCSI ID it finds (3 in my case)

If I boot the pdq first, then only boot the pb100, then in the system properties, ALL the scsi ids from the pb100 are exposed (which is unexpected) however I can only mount the first one (ID3) for whatever reason. It says the other IDs "have one or more locked disks", and finder crashes if I try to mount them.

Okay so I'm a bit lost here
- the dock/scsi switch seems to do nothing apart from putting the pb100 in target mode without hitting a key (?!),
- but this changes nothing on the scsi end , all IDs are exposed (?!), the "set up ID" (in the pb100 control panel) does nothing and never appears anywhere (?!)

For what it's worth, I can put the scsi/dock cable in scsi mode, boot BOTH computers, and the PDQ sees again all the disks of the PB100 (and again only one can be mounted)

I think someone with more macOS/system7 experience than me can make sense out of this ?
I'm probably using it wrong
 
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avadondragon

Well-known member
PDQ sees again all the disks of the PB100
I take it you're using some form of SCSI - SD device emulating more than one drive? I've always wondered what would happen if you put one in dock mode while emulating multiple devices since the machine was never intended to have more than one internal drive. I'd be curious to see if anyone has had success with this.

I'm not 100% sure if it will work but you can try holding down the d key while booting to try and force the internal drive. Here's the magical boot key list for your reference.
 

Cedsrepairs

Well-known member
I think I may be adding problems on top of problems by having multiple partitions in my pb100 ; but I also think something is not working like it should

What I’ll do is simplify my setup by having a single partition ( scsi Id) in my bluescsi to be closer to the original ( as I have two pb100 one with still a spin disk I could also try there )

I really believe the knowledge about how this works is starting to vanish : I’ve seen maybe two people using the target mode on the internet …

My main questions remain ; why on earth does the pdq see multiple scsi Ids ; why does he completely ignore the scsi id setting from the pb100 target mode settings which seem to serve no purpose
I also think maybe my pdq boots from scsi because it lost pram ; I’ll investigate that as well .

That is really not as simple as it should be
 

avadondragon

Well-known member
You may be the first person to try using dock mode with multiple SCSI IDs on the internal SCSI port of the PowerBook. It was never designed to work that way so I wouldn't be surprised if it breaks things. I've been meaning to try this but I have never gotten around to it.
 

Cedsrepairs

Well-known member
Yeah, I'm always a bit scared to be the only person on earth interested by something :)

Anyway I did multiple tests

Whatever I do, if I connect a PDQ (MacOS9.2) to a PB100 (System 7.0.1) thru target mode, the PDQ tries to boot from the PB100 disk.

So if I boot the PB100, which automatically goes into Target mode when connected with the proper connector in DOCK mode, and then only boot the PDQ, and after that connect the scsi cable (I know this is not recommended) I can get the PDQ to show a single SCSI ID "6" (matching the control panel settings) which is NOT mounted by default.

If I go to the disk utilities, and hit %M then it mounts and I can access the PB100 disk from the PDQ.

So even with a PB100 with a spin disk, the cable does not work like it should (I think)
- it should not boot from scsi (my pdq should boot from it's own IDE!)
- the disk is never auto mounted and does not appear on the desktop (documentation says otherwise)

It seems the fact the SCSI ID did not appear as they should was specific to my initial bluescsi setup. I believe the Dock cable (and the logic in system7) clealry expects to system disk to be SCSI ID0, and then only it'll "map" that SCSI ID 0 to whatever ID you specified for target mode.
If your internal drive (bluescsi or otherwise) has any other scsi id than 0, then it seems nothing is working as it should.
 

Cedsrepairs

Well-known member
A few pictures

The cable setup i'm using, black on PDQ, gray "scsi/dock" on PB100. DB25 in between.
Interestingly and as documented, the dock/scsi connector has an extra pin, compared to regular hdi30.
ced_2023-03-05@16h41_IMG_0138.JPG ced_2023-03-05@16h41_IMG_0139.JPG



When both are connected, start traget mode on PB100, then only boot PDQ : PDQ tries to boot from SCSI target (?!)
ced_2023-03-05@16h11_IMG_0137.JPG


When you hot plug the scsi cable AFTER both devices are booted, then only can you "mount" the disk, manually, from disk utils.
ced_2023-03-06@15h48_IMG_0143.JPG
You can clearly see target 6 appearing.
But this is supposed to automount (it does not) and is not supposed to require "hot plugging" the scsi after boot (?!)


Just FYI : this is what happened with a bluescsi with multiple IDs connected. The "scsi id" from the target mode is basically ignored, and ALL scsi ids appear, unchanged (matching the ones on the bluescsi), to the PDQ. But only one of them can be mounted, the one with the lower ID, the other ones are "locked". Interestingly it's not even the bootable ID that can be mounted.

ced_2023-03-05@15h49_IMG_0133.JPG
 

3lectr1cPPC

Well-known member
This stuff is really not meant to be hot plugged… I’d be quite worried about frying something if I were you.
 

Cedsrepairs

Well-known member
If you're not hot plugging, the only thing this setup does is trying to boot from the disk...

Under no circumstances (spin disk or bluescsi) was I able to have the PDQ boot from it's own disks. It wants to boot from the target mode for god knows what reason. Which of course does not help at all ; of course System7 does not support a powerbook G3, and usually a target mode is more for a rescue operation or file copy.

Weird weird weird.

Again i'm very new to all this so maybe/probably i'm doing something wrong. Maybe this dock/scsi adapter does only that (boot from the target) but it's not what I've read on similar threads.
What I expected to happen is very simple ; my pdq should boot like it usually does, the external disk should appear automatically on the desktop, and technically it should be the "fake" SCSI ID that was set up in the PB100 control panel.
None of this happens.
Maybe my pdq is braindead or feels alone and desesperately wants to boot from it's external SCSI disks.
 
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3lectr1cPPC

Well-known member
make sure the PDQ’s drive is selected in startup disk?
You can also force boot a SCSI ID using a key combination, just google for it and you’ll find a page with it. Maybe if you try to boot from a non-bootable ID, it will go to the IDE Hard drive instead?
 

Cedsrepairs

Well-known member
And to say something positive in all this : when the disk is recognized (even if it's thru my brutal hotplug method for the moment) this is super handy : I can access the PB100's disk super mega fast, I was able to copy all of the documents from the PB100 in like 3 seconds which would have taken hours to do with floppies ( this is a PB100 it does not have many ways to communicate with the external world :) )
Also I can add downloaded software to it (.sit, .bin, floppy images, etc) MUCH faster than any other method.

If only it would work like it should ( not prevent pdq from booting + auto mount as external disk on fake scsi ID) that would be great.
 

Cedsrepairs

Well-known member
Holding "D" does nothing good, it still boots from SCSI.
MGNIAAARHHHHH
O-F does nothing either ( Wallstreet PDQ )

I carefylly read the PB1xx and the G3 manuals.

In fact what's unusual is to connect two laptops together. It simply not documented ; they take for granted to receiving "host" will be a desktop, with a DB25.
It's also not documented if you need, while connecting two HDI30 together, a 30 pins adapter in one or two ends.
Clearly, the only thing the dock/scsi adapter does, for me, is auto start the sharing disk in "target" mode without needing to hit "T".

Why does my PDQ always want to boot from HDI30 SCSI is simply a mystery.
I double checked that my internal IDE drive is marked as fixed in the settings. It's also selected in the startup menu as boot disk.

Until I can make the PDQ start normally while connected to a SCSI target disk, I'm really stuck.
 

3lectr1cPPC

Well-known member
I can set the startup device I think though for the internal drive. But all the PRAM batteries are dead or removed, so it doesn't remember after being unplugged.
 

Cedsrepairs

Well-known member
I'll try again to get into open firmware

there seems to be a "multi-boot" command, EVEN ON A WALLSTREET, that i'd like to try.

My pram battery has been replaced and works even for sleep mode. I also tryied COM-OPT-P-R to zap the pram.

I need to deal with one problem after the other. Clearly what I try to do combines many different problems and is super obscure.

If you confirm a wallstreet will always autoboot from scsi (which I didn't know), then my first problem is how to prevent this.
 

Cedsrepairs

Well-known member
If you could find what would prevent it from auto booting on scsi ( « D » does nothing here ) that would be great
 
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