Author Topic: Optical Drive replacement on Power Mac 8500 with System 9.1  (Read 662 times)

Offline fsangre

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Optical Drive replacement on Power Mac 8500 with System 9.1
« on: March 03, 2017, 12:42:41 PM »
Hello you all from Spain (new member asking for help).

I have an old Power Mac 8500 I'm trying to keep working as a controller for a big pro scanner I often use, that requires a SCSI connection and System 9.

Recently I realized that the original CD-ROM drive (8X Matshita CR-8008) can no longer read CDs. It works mechanically, but after a long series of treatments with a special cleaning CD, I'm beginning to think that's done.

As the Optical Drive is needed for software installation and license renovation, I must implement some solution.

My first (obvious and preferred) option is to replace the internal SCSI drive, if I can locate and purchase a compatible one. And here comes my first questions:
Apart from the required SCSI interface, do you know what specs must have the "new" drive to work in my system? It'll be necessary to install MacOS 9 special controllers or the base System Extensions are enough?... and, Do you know some place where to buy it?

Another option is to install a USB PCI card and purchase an external USB CD/DVD reader.

And finally, I also have a Power Mac G4 with system 9 and a working optical drive but without a SCSI connection, so another option can be to install a PCI SCSI card to connect the scanner and retire the old 8500 friend.

Any advice on these? In those two cases, I have tried to find the PCI cards on Internet, but all I can find are second hand cards sold As-Is and, I'm afraid them comes without software I suppose is needed.

Thank you very much in advance.

Offline ssp3

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Re: Optical Drive replacement on Power Mac 8500 with System 9.1
« Reply #1 on: March 03, 2017, 01:19:44 PM »
Just find cheap, but not beaten-up Plextor 12TS or 20TS and away you go. Front bezel might require slight filing, but that's an easy job.
I've been running my 8500 with various Plextors since 1998 or so.

Offline fsangre

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Re: Optical Drive replacement on Power Mac 8500 with System 9.1
« Reply #2 on: March 04, 2017, 10:21:09 AM »
Thank you very much ssp3, I've made a quick search in eBay a found a Plextor PX-20TSi here in the EU. I suppose is one of the ones you mentioned. Can I also suppose that there's no need of extra system software to make it work in MacOs 9.1?

Again thanks for your advice

Offline ssp3

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Re: Optical Drive replacement on Power Mac 8500 with System 9.1
« Reply #3 on: March 04, 2017, 02:39:13 PM »
I think one needed modified Apple CD/DVD driver, but that shouldn't be a problem.

http://siber-sonic.com/mac/Vintage/CD_DVDdriver.html

Offline fsangre

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Re: Optical Drive replacement on Power Mac 8500 with System 9.1
« Reply #4 on: March 05, 2017, 04:43:09 AM »
There's a lot of useful info on that link.

By reading it, seems that the possible troubles of installing a non Apple CD/DVD drive are the bootability of their firmware, but also states the low probability of them.
Also recommends to have Apple CD/DVD Driver v.1.4.8 installed on System 9. In my case the Driver installed in the System 9.1 on the 8500 is v.1.4.3, but I have access to an Apple CD/DVD Driver v.1.4.7 from my PM G4 with System 9.2.2

So I'll go for it and get that Plextor PX-20TSi and cross fingers it will works smooth (seems probably it will be the case). I'll return here to share the experience.

Thank you very much again

Offline fsangre

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Re: Optical Drive replacement on Power Mac 8500 with System 9.1
« Reply #5 on: March 14, 2017, 06:59:07 AM »
Well, I'm back to share the news about my old PM 8500 SCSI CD-ROM drive issue... and unfortunately they are not good ones.

I've just received the Plextor PX-20TSi and realized that the connectors at is back arenīt the same as the ones in my old internal Apple CD-ROM drive. As you can see in the photo attached (old drive left, Plextor right), neither the SCSI connector, nor the AUDIO connector are the same, so as those are soldered to the controller board with the actual drive mechanism, I think the only possibility to make that Plextor work in my 8500 would be to connect it via some sort of adapter... that I think does not exist.
Totally my fault to not checking carefully the connectivity. I only say in my discharge that I previously haven't heard about different internal SCSI connector existence and the lack of extensive description or enough photos from the online seller.

So, back to square one. Well, the positive outcome of this is now a little more about SCSI internal interfaces, at a cost of 45€ + shipping  :-[

Offline ssp3

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Re: Optical Drive replacement on Power Mac 8500 with System 9.1
« Reply #6 on: March 14, 2017, 02:00:13 PM »
Hello fsangre.
As they say, "education costs money, ..." ;)
It looks that you've scored relatively rare Ultra Wide SCSI version of Plextor.
The good news are that it could be adapted to 50 pin cabling, since Narrow to (Ultra) Wide adapters exist, but the bad news are that UW device needs to be the last one on the Narrow SCSI chain with its termination activated. If I remember correctly, in 8500 the hard drive is last on the chain.
If you can change your cabling this way:
motherboard -> hard drive (termination OFF) -> Plextor (temination ON)
the you'll be fine.
Just pay attention to 50 pin to 68pin adapter form factor, so that it does fit and not interfere with 8500s power supply and other cabling.

Google for "scsi 68 to 50 adapter". From my experience, DataMate adapters are the most compact. Check this ebay listing: 322442924890

As to the audio connector, yes they are different, but the odd one here is Apple/Matsushita, not the other way around.
Besides, you've said that you need your Mac with working CD-ROM for some super-duper scanner (drum?) and not for playing audio. Wasn't it so?;)

Offline fsangre

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Re: Optical Drive replacement on Power Mac 8500 with System 9.1
« Reply #7 on: March 15, 2017, 06:12:31 AM »
Thank you ssp3. I always believed in the value of knowledge; but, same with other valuable things in life, problem comes when that value is translated to price  ;)

You're correct remembering me that to maintain audio capabilities of the CD-ROM drive isn't the main reason to replace it. But it will be nice if possible, even if the use of the PM 8500 now is, nearly exclusively, to serve (yes) an old Scanview drum scanner.

The narrow to wide/ultra wide internal SCSI adaptors do exist (thank you) so maybe it can be used to make that ultra wide Plextor drive work inside my system. I checked the eBay reference you mentioned, but it's a male (68 pin) to female (50 pin) adapter... It seems to me that I'll need a male to male adapter, as the internal SCSI cable and the Plextor drive both have female connectors. Anyway I've also located them.

Apart from the trick needed for cabling the internal sequence (two HDDs plus the Optical drive) to make the Plextor the last one in the SCSI chain, what worries me is to terminate it. On the old drive you have a bumper clearly identified to enable termination power, but in the Plextor, it seems that there's no such an option (or at least as long as I -barely- know). Will I need an internal physical terminator?