Assigning SCSI chains

[SE30_Neal]

hi guys,

I’m looking to daisy chain SCSI peripherals to my SE/30, i’ve not done this before and could do with some advise as i notice some of the peripherals require assigning a scsi daisy chain number others don’t, i have the following:-

-Zip100 no scsi assignment number

-AVID external HHD has assignment number.

-Apple 300 CD-ROM has assignment number.

-None branded CD-ROM no assignment number.

-UMAX Astra 610 Flatbed scanner also  has assignment number.

i would like to set up the daisy chain to my SE/30 so questions are:

1.) do i have to set them up in any kind of priority order, ie those with auto numbering first or hhd first

2.) do i need to have them in order of the chain ie if say the avid hhd is first link in chain that must be 1

i know the last in chain requires a terminator which is fine as i have one.

any advice of setup would be most helpful.

thanks 

Neal

 

[Trash80toHP_Mini]

-None branded CD-ROM no assignment number.

That's the one you try first, installed by itself with no termination, Use SCSI-Probe to find out what its assigned number would be and whether or not termination is set. That you'll make the end of the chain if it's terminated if you don't wanna crack the case and fiddle with the drive itself.

-Zip100 no scsi assignment number

That sounds very, very bad. On the back of the case between two DB-25F connectors there should be two vertical switches, one tuns termination on and off and the other sets its SCSI ID to either 5 or 6. If you don't have those two switches something is wrong. If you have one Male and one Female connector it's a Parallel Port drive as worst case or a Zip-Plus which is another kettle of fish entirely, but best case if it doesn't look as described above. Don't recall the setup options for that on offhand.

Found a piccie:

from: https://ancientelectronics.wordpress.com/2013/11/13/odds-ends-trs-80-model-100-iomega-zip-drives-gravis-gamepads/

edit: forgot the conclusion! You'll be setting up the rest of the chain IDs so as not to conflict with the CD and the Zip IDs with the CD on the end of the chain if the SCSI-Probe test tells you it's terminated. If it's not, that first test above will yield a flashing "Bus not terminated" warning.

 

[SE30_Neal]

Hi trash, yes the zip drive i have is the bottom one in your picture with switches. I had connected the zip and none branded CD-ROM drive before but then wasn’t really sure where do go with adding the other 3 peripherals that have these assigned numbers on the back. From what I’ve read scsi chains can be up to 7 and some peripherals need to be manually set. I’ve not dealt with these peripherals with fixed numbers before as the CD-ROM i had it running to the zip which had inbuilt termination which worked fine with just those but I wanted to add my other items to the equation.

 

[Trash80toHP_Mini]

OK, your Zip is easily configurable, use the CD alone without termination and run SCSI-Probe to find out how it's configured. After that it's building blocks time. There should be buttons to push (which may need to be flipped up to do so) to rotate thru the IDs in sequence to set them to non-conflicting addresses to CD and Zip at 5 or 6 in the chain. Have fun!

SCSI-Probe is your friend. []

 

[SE30_Neal]

Ah ok thank so i need to stay away from channel 5 and 6. I don’t have a probe but can add one item at a time.

 

[chu-oh]

You should try and your hands on a scsi-to-ethernet adapter purely to see how far this can go.

 

[SE30_Neal]

Haha. I’m happy to add more to the chain for sure  although i do have a network card in zippy my little se/30 already lol

 

[SE30_Neal]

Haha. I’m happy to add more to the chain for sure  although i do have a network card in zippy my little se/30 already lol

damn not enough scsi cables

 

[SE30_Neal]

You should try and your hands on a scsi-to-ethernet adapter purely to see how far this can go.

It is a maximum of 7 peripherals, can you use 0 in a scsi chain to make it 8?

 

[Trash80toHP_Mini]

The Mac is at SCSI ID 7 and its internal HDD is SCSI ID 0 and 7 in this screen shot, so your chain limited to six additional peripherals. Boot drives are ID0 and CDs are usually ID3 IIRC.

macintoshgarden.plug

Ah ok thank so i need to stay away from channel 5 and 6. I don’t have a probe but can add one item at a time.

My bad, I wasn't clear enough in my explanations, it's a software utility. http://macintoshgarden.org/apps/scsiprobe Download it and use it to do the first test:

Hook the CD alone with no external termination up to the SE/30, run SCSIProbe and it will tell you what ID it's using and whether or not there's termination built into the box. Build from there. You only need to avoid 5 or 6 depending on the switch setting of your Zip Drive.

 

[SE30_Neal]

The Mac is at SCSI ID 7 and its internal HDD is SCSI ID 0 and 7 in this screen shot, so your chain limited to six additional peripherals. Boot drives are ID0 and CDs are usually ID3 IIRC.



macintoshgarden.plug

My bad, I wasn't clear enough in my explanations, it's a software utility. http://macintoshgarden.org/apps/scsiprobe Download it and use it to do the first test:

Hook the CD alone with no external termination up to the SE/30, run SCSIProbe and it will tell you what ID it's using and whether or not there's termination built into the box. Build from there. You only need to avoid 5 or 6 depending on the switch setting of your Zip Drive.

 Thank you trash, that is just what I’m after. I’ll download that. Brilliant 

 

[SE30_Neal]

The Mac is at SCSI ID 7 and its internal HDD is SCSI ID 0 and 7 in this screen shot, so your chain limited to six additional peripherals. Boot drives are ID0 and CDs are usually ID3 IIRC.



macintoshgarden.plug

My bad, I wasn't clear enough in my explanations, it's a software utility. http://macintoshgarden.org/apps/scsiprobe Download it and use it to do the first test:

Hook the CD alone with no external termination up to the SE/30, run SCSIProbe and it will tell you what ID it's using and whether or not there's termination built into the box. Build from there. You only need to avoid 5 or 6 depending on the switch setting of your Zip Drive.

Hi trash,

quick question if i may, i setup my se/30 and the bunch of scsi peripherals today as my 50pin scsi cables arrived. So far I’ve not had chance to setup my bridge computer or 2001 imac so haven’t been able to download the scsi probe software yet, hopefully all being well i’ds be able to do so tomorrow but as you can imagine last Saturday before xmas i’ve been some what busy thanks to my wife lol. Anyway, question is about the external hhd which i set to 1 on the back as in was first peripheral attached to the mac and now (if the external drive is on) the mac tries to boot directly from the external hhd (flashing floppy on screen) is that down to me setting the scsi number wrong or will i need to open up the hhd to change jumper setting to slave as you would on say a mid 2000s pc?  I may have to open the mac too and make sure its set to master as i never checked when i installed it. For reference its not the original quantum drive but a later 1994 1Gb drive.  I may have answered my own question there but wondered if it is just a setup issue before I disconnect it all and take screw drivers out? Thanks Neal

 

[Trash80toHP_Mini]

There's no master/slave setup confuzzlement in the SCSI spec. IIRC the Mac just boots to the lowest SCSI ID, which is why internal HDDs are set to ID0. Unhook the external drive and try setting your internal drive as the boot disk in the Startup Disk(?) Control Panel. Then hook the external back up and test again.

 

[Cory5412]

Is there a system folder on the external drive? If not, the system should pass over it once it has checked it.

If there is, another option to force a particular boot device is you may un-bless it by dragging the "System" file out of the folder and placing it elsewhere. When you do that, the Mac should go bakc to booting from your internal drive.

If you need to boot from that external hard disk again, re-bless the system folder by placing the system file back in, and then reboot. (Or, if all your OS installs have it, the Startup Disk control panel that jt mentions should also work.)