Hi,

RE previous

Am trying to set up my Quadra's internal Matsushita CR-507-C CDROM 12x drive in an external case to connect to my TAM.

The drive appears to have ID3, which clashes with the TAM's internal CDROM.

The drive has pins labelled:

Parity/ID0/ID1/ID2/././Term Power

with jumpers on the first 3, and last pins.

What do I do to change the drives' ID? I have a terminator attached to the external drive case... is it needed? Causing a problem?

Cheers


Travis

(No, the TAM's scsi still hasn't re-engaged after trying various re-setting options after getting the new PRAM battery... but thought I'd give this a try, as my main objective is to install MP3s on the hard disk).

Hi try this
(Parity/ID0/ID1/ID2/././Term Power) copied from your post
you said you jumpers on thefirst 3 take the jumper of ID0 and put it on ID2 cant rember what scsi id it is, from what i remember ID0,ID1,ID2 control scsi IDs just play around with them just make sure its powered of, trial and error will get it in the end thats how i found out, i did write down, filed it in a safe place never to found when wanted

Thanks Pismo. Moved the ID0 to ID2... also removed the external scsi terminator from the box and it now shows up on SCSI Probe as ID6. Though the other information provided is garbled, and it will not mount. But that's a whole other story. Mmm, can see a moderator joining this post to my TAM related post any second...

Ok have found the piece of paper here is scsi settings
Scsi ID Jp0 jp1 Jp2
0 off off off
1 on off off
2 off on off
3 on on off
4 off off on
5 on off on
6 off on on
7 off off off this cant be used as it is resevered for macintosh
how is your cable conected terminator on the top conection

I had the scsi cable on the bottom, terminator on top... and it wouldn't see the drive. I swaped it over - still nothing. But when I left the cable on the top, and the terminator off, the drive showed up on SCSI Probe (but garbled, not mounting).

Your diagram fits the puzzle though - I moved the jumper on ID0 to ID2, and left the jumper on ID1, and it now comes up as SCSI ID 6. I think that matches one of my external drives, but at least now I have the list above to change it to anything I want Thanks.

Now I'm just trying to figure out how to disconnect the internal vertically mounted CDROM in the TAM so that hopefully the external SCSI chain will correct itself.

90% of what you need to know about SCSI is covered by the ID (from 0-7 or 0-15 depending, in your case the former) and termination.

The ID is controlled by three jumpers which use simple binary. To count from 0 to 7 in binary (Base 2 - that is, you reach "10" at a count of 2 instead of a count of ten in our regular Base 10) you count thus:

0
10
11
100
101
110
111

With leading zero's to make it easier to comprehend:

000
001
010
011
100
101
110
111

In old Macs, we know that the computer's ID is always 7, the main HD is 0, and the optical drive is 3. The counting system above directly translates to the pins on any SCSI HD or optical drive. A basic knowledge of binary is also very useful when having to Mac OS X/Linux/Unix file permissions.

Part 2: Termination:

So as to stop the SCSI signals being reflected back down the wire, SCSI chains require terminators - basically blocks of resistors that sit on the very end of the chain. Some devices have built-in termination, activated either via a jumper, or have removable resistor blocks near the connector.

Your optical drive appears to have jumper-controlled termination. You don't need a terminator if there's a jumper across the TERM pins. See if removing that and using a terminator makes any difference.

As for mounting - if you're using OS9 or earlier, Apple only included software to recognise brands of drives that it supplied with machines. You can get around this if you have the Apple CD-ROM version 5.3.1 extension which provided support for 3rd party drives. Later versions wont work.

Memory must be slipping forgot about Apple CD-ROM ver 5.3.1 thanks Currawong for recharging the grey matter,
Anyway cosmichobo it may be your lucky day i browsed though my garage and came up with a scsi Apple 24X model CR-508-C that came out of a black mac 5500/255 i know it works i had it in a external case leave me a message with you name and address and i free post it to you Monday it may as well have a new home

A couple of things:

1) if you need Apple CD-ROM 5.3.1, PM me.
2) SCSI is voodoo, and whilst I don't know the specifics of of the TAM's SCSI layout, the fact that it uses architecture more akin to a laptop than a desktop machine, I would put good money on the fact that the TAM does not provide its own TRMPWR signal.

If the latter is the case, and you have either an Apple-badged CD-ROM drive or the 5.3.1 driver, then you're going to need an active SCSI terminator block, or run without termination at all.

(Oh, if the terminator block you have been using is black, don't use it -- this is a special terminator for use with the IIfx only)


Brains