Macintosh Plus Silverlining freeze

[Ike]

Okay... yet another problem with my macintosh pluses. lets see if this is fixable too!

So i'm very new to the scsi system of connecting external drives.

i bought a new SyQuest drive in scsi enclosure for my macintoshes, it came with 11 new 88mb disks.

set up the system to a mac classic and booted from a floppy disk (my classic has no hdd installed since it went bad a while ago)

before the happy mac icon and 'welcome to macintosh' screen, once the SyQuest drive was on, the mac would display a silverlining window with the chosen SCSI ID (0 in this case) and it would boot from the floppy... moved some system files to the cardrige and tried to reboot from the SyQuest without help of a boot floppy.

SUCCESS! :b&w: Booted right up and fast too !

Tried to hook this same system up to either of my working pluses... and it hangs on the 'silverlining' screen.

the text is a bit distorted and it just sits there with no disk activity at all

The window said Silverlining lite 5.7 iirc

Do you guys know this SyQuest drive system (SyQuest 200 MB C) or the additional requirements to get this working on a plus?

Thanks in advance, i hope you can help me

 

[onlyonemac]

If I'm not mistaken SCSI 0 is reserved for either the Mac or the internal hard disk (not present in this case).

 

[Ike]

also read that somewhere...

problem is, my classic boots right off it using ID 0 and my plus locks right up,

tried settings the id to for example 4, it shows the right ID on the splash screen using the classic as well as the plus... but the plus still freezes.

at least i know the id selector on the back of the external drive bay works

is this maybe a version of the driver that is not compatible with a macintosh plus?

 

[Scott Baret]

Really digging back deep here, it's been a long time since I've had a Plus up and running, but a few things to consider:

1. The Plus is one of two quirky Macs when it comes to SCSI (the IIfx being the other). I remember reading the Plus was designed with an earlier, not 100% compatible with all device version of SCSI. There are also issues with certain ROM revisions. Find which ROM version you have, as the two earlier revisions sometimes have some problems with SCSI devices (although I don't think what you're describing sounds like it could be a ROM-related issue, you never know what can still be discovered about these old Macs--funny how I say that just a few days after I said we had just about everything under the sun figured out).

2. It may be worth trying to format on a Plus. There may be some quirk in the Silverlining drivers. I've used Silverlining 5.5 before and have never had an issue, yet I've never really formatted drives for use on several different Macs. For a hard drive, the Plus does best with a 3:1 interleave ratio. Classics and SEs need 2:1 while other Macs (020 and up) can use 1:1. This is more of a performance issue than compatibility, however, and probably won't apply to SyQuest disks (though it could--I don't have a disk to test with--but it didn't seem to affect Zip disks when I used them with a Plus many moons ago). I also have an 80MB drive (Apple-branded) that I got with a Plus that only works on a Plus. When I put it on an LC, it wasn't recognized at all.

3. In regard to SCSI numbers--for future reference--the Plus scans down the bus from 6 to 0. This cannot be bypassed by the Startup Disk (Startup Device on System 6) control panel. In fact, the control panel doesn't even open on a Plus. (Again, this has to do with the Plus having an early SCSI standard on board). On Macs with internal hard drives, 0 is always the internal hard drive. There's also a SCSI number 7. DO NOT USE this one--it's reserved for the Mac itself.

I'd go ahead and try to format one of those cartridges on a Plus.

 

[beachycove]

Silverlining 5 (not 6, as I recall) has recommended settings for formatting on different machines. I don't think the one for the Plus is the same as for later Macs.

Digging a little deeper in Silverlining might offer a solution.

Edit:

I may be thinking here of Anubis, which dates from the Plus era.

 

[Ike]

Thanks for your very complete answers guys!

I am aware that the plus does not have the SCSI standard onboard because the standard released later, i think that can very much be one of the causes.

I'm going to try to format one disk on a plus itself. problem is that even when i boot from a floppy as soon as i insert the disk... the complete system also freezes...

and there is another quite problematic thing about SyQuest drive readers...

i have a drive made for reading 200mb disks... you can also read and write the older 88mb and 44mb... but i read somewhere that i can't FORMAT the older types of disk.

did not try it though.

i'm quite worried that the problem has nothing to do with the formatting of the drive YET. Because it just fails on loading the driver altogether.

also maybe interesting to know is that a new cartridge has like 3 or 4 partitions on it, the biggest off course being the partition that shows up and you can write your own data to.

also, is there an easy way to see which rom revision i have?

Can you also maybe give me a link to a short introduction on how and where the drivers for a drive are stored and how that works... i really want to get into that hoping to fix any future issues.

Come to think of it... i did not try the drive on my SE yet...

Edit: YUP, booted right up on the SE as well.

i'll stop typing now and keep you updated

 

[trag]

Do you have the drive terminated? I am assuming it is the only SCSI device connected to the Plus, which means it is at the end of the SCSI chain, which means it should be terminated. There are probably two SCSI connectors on the back of the Syquest drive. You use one for the cable. The other, if not used to connect to another SCSI device, should have a terminator installed on it.

The Plus is different from other Macs in that it lacks motherboard termination for its SCSI bus. So, if you do not have the Syquest drive terminated, then your SCSI bus has no termination at all and that could cause the lock up you are experiencing.

On the Classic and SE, the logic board or the internal hard drive terminates its end of the SCSI chain, and while the last external device should be terminated, if there is only one external device and the cable is short it will probably work without termination. But on the Plus this doesn't work because in that circumstance, there is no termination at all on the bus/chain.

 

[onlyonemac]

I think what trag is trying to say-or at least what I've read before-is that you have to terminate both sides. I remember reading that it has to go something like this:

Plus-Terminator-First External Device-Second External Device-More External Devices-Terminator

That's right-there must be a terminator between the Plus and the first device.

 

[Scott Baret]

The advice is correct. I had almost forgotten that the Plus does not provide termination power.

There used to be terminators you could connect to the drive, then connect the cable to the terminator. The hard drive I got with a Plus had one. I'll try to illustrate it as best I can with text:

((MAC PLUS)) ----SCSI CABLE---> {{TERMINATOR WITH CONNECTOR}} ---> ((SCSI DRIVE)) ---plus a terminator on the other SCSI port on the drive.

 

[mcdermd]

A "pass through" terminator?

 

[onlyonemac]

I would describe it as "pass through"-if anyone knows where to get them!!!

 

[trag]

Yes, but what I am saying in this case is that I suspect that his Syquest drive has no termination at all on it. Never, mind the hard-to-find pass-through terminator. He probably doesn't even have the final termination block in the unused cable connector.

If that is the case, in theory, the Syquest should not work when plugged into the SE or Classic either. However, it does work, and that is because the cable is short and one end of the bus is terminated in the SE or the classic. Not the way it should be, but it will usually work.

On the Mac Plus, assuming the Syquest is not terminated, there is no termination anywhere on the bus at all. And that almost certainly will not work. Just plugging a relatively easy to find termination block into the unused cable socket on the back of the Syquest will probably get it working, assuming the Syquest is the only external device.

What I assume is happening now:

T:InternalDrive==Classic====Syquest

T:InternalDrive==SE====Syquest

or

T:SE====Syquest

Plus====Syquest

What the first two *should* look like:

Trive==Classic====Syquest:T

Trive==SE====Syquest:T

or

T:SE====Syquest:T

What can be done to make the Plus work:

Plus====Syquest:T

What the Plus really ought to look like:

Plus:T====Syquest:T Good luck finding a pass-through 25 pin terminator.

or

Plus====T:Syquest:T

And the Plus if more external devices were used:

Plus====T:Syquest===Drive===Drive====Drive:T

Where :T or T: is termination on the device adjacent to the text.

 

[Scott Baret]

Yes, a pass-through terminator. I had forgotten the name.

If only I were in Pittsburgh at the moment--I think I have at least three of them laying around.

 

[Ike]

Oh my god, away for a few days and BAM, Lots of information!

I have the end of the drive terminated with a pass though terminator!!

just tried it out with just connecting the terminator between the cable coming prom the plus and the drive connection, leaving open the port for the next device on the drive...

that makes no difference... (i don't have a second terminator yet so that is a bit of an issue )

weird thing is that i have exactly the same drive enclosure with a semi-dead quantum prodrive els in it... that will work just fine with the terminator only on the port to the next device once the drive wants to unpark. But that is maybe because the drive has the terminating resistor packs installed right?

Also tested the termination with an apple cd 300 plus, it did not show up when not terminated, it did however as soon as i added the terminator... so that visually made a difference.

It also showed up using the pass through terminator between the plus and the CD player.

 

[onlyonemac]

Ike, your post was hard to follow. Where exactly are the terminators? Please give a diagram in trag, Scott Baret, or onlyonemac SCSI notation .

 

[trag]

Ultimately, you may find that the problem is not termination related. However, until you are sure you have proper termination installed, you can't be certain that it is not termination. So get good termination installed, and if it doesn't work, it is something else.

 

[Ike]

okay so a weird thing just happened:

Had my classic boot form the internal HDD, with the syquest drive attached to the scsi port, the bottom port on the exclosure having a terminator.

Took the guts to load a copy of Lido just to see what it would do... Chose the easy setup and chose a disk icon, the disk started rambling away...

Strange -> a SyQuest 200MB drive is NOT capable of formatting 44mb or 88mb disks, yet is was just happily formatting (not initializing) the disk. Success #1!

After that i noticed the silverlining driver to be totally gone... rebooted the mac and it saw the SyQuest as a normal hdd without any boot logos.

Back to my plus, same setup using the drive with only one terminator on the end of the chain...

Kaboom! it showed me the 'this is not a startup disk' icon on startup, pushed in a floppy, it booted, i can see the drive on the desktop and it behaves like a normal harddisk.

Another problem solved

 

[onlyonemac]

You still haven't got a pass-through terminator???

It's about time you get one, then all your troubles will be gone.

 

[Ike]

no i have one, but only one. so i cant test it with a pass trough terminator between the plus and the disk and then ANOTHER terminator on the end of the chain.