Retro addons: Big box o’ SCSI part 1

An oddity popped up recently which I ended up acquiring. An external box with 4 interesting SCSI devices inside and a SCSI card for a RiscPC. Time to dive in and see what we have…

All the devices

The box itself is unbranded, which is a shame because I can’t find anything about it at the moment. But it has a power supply and four drive bays. On the rear is a SCSI ID setter and two Centronics SCSI ports, the top one containing a terminator.

For those not familiar with SCSI, it is a fast and reliable method of communicating drives that was very popular with people dealing with things like video. SCSI can have more devices on a single cable (hence the need for SCSI IDs), but the cable needs to be terminated at the end.

From top to bottom in the drive bays we have:

• An HP DDS3 tape backup drive
• A Cumana proTeus drive
• A SyQuest 88MB cartridge hard drive
• A removable hard drive bay, no hard drive installed

As for accessories we have:

• A SyQuest 88MB cartridge in case
• An empty 88MB SyQuest case
• A Panasonic PD disc
• 2x 24GB DDS3 backup tapes, one in box
• A Cumana branded RiscPC SCSI card
• A SCSI cable to hook it all up

Inspection

I didn’t want to just power this thing up until I had at least inspected the power supply. I therefore opened everything up to see what was inside.

Most of the SCSI ID cables have not been wired up, the drives have had their IDs hard-coded with jumpers instead. The PSU looks file and everything appears to be quite clean. I’m guessing this wasn’t heavily used.

Power on test

I plugged everything in, powered it on and the drive lights started flashing and doing things, which is a good sign. I then installed the utility software on my RiscPC for the SCSI card, I’ve made this available on my downloads page.

Unfortunately when attempting to first run the software it hung whilst trying to detect the drives and wouldn’t return. My hazy past history with using SCSI told me to check the IDs and make sure everything was good there. Sure enough the proTeus drive and the SyQuest drive were both set to ID 1. I reconfigured the SyQuest for ID 2 and the diagnostics utility showed that things seemed to be working now:

Interestingly the proTeus drive shows as two drives, but I’ll get to that later. The good news is the drives can talk to the computer at least.

Cumana proTeus

This drive is one of the most interesting ones to me, because it is a technology I did not know existed. As with most Cumana CD drives, this is a Panasonic / Matshita drive that has had Cumana branding stamped on the drive door.

I found the following double page spread and news article about it in 1995 issues of Acorn User.

The proTeus drive is what is known as a PD drive, PD standing for “Phase-change Dual”. It is a re-writeable format that allows you to edit on a file by file basis rather than track or disc at once. The technology is the precursor to DVDRAM.

The tray allows for a regular CD or a PD disc which comes in a cartridge.

This is why it shows as two drives on the SCSI port, one a CDROM drive and the other the PD drive, which is more like a hard drive to the computer.

As a CD drive, it works great, but when I put the PD disc in it would try to spin up and then immediately eject it. Not ideal. I decided to disassemble to drive and see why it wasn’t loading in.

The right hand side of the last photo is key here. There is a belt-driven eject/load mechanism. The gear system uses a rack and pinion system to move the tray. Once the tray is pulled all the way in the gear system continues for a short while to twist the two white curved pieces of plastic. This lifts the entire mechanism up. This is also where the problem lies.

For a CDROM this doesn’t need to lift far and catches the disc without issue. But for the PD discs it has to rise up through the cartridge. This wasn’t happening, the belt was slipping before it rose far enough. The drive then ejected as it knew it wasn’t completely loaded.

I’ve ordered a replacement belt, but in the mean time I greased up the raising mechanism and re-assembled for now. After a few tried I got the drive to accept the disc. Unfortunately it doesn’t seem to be readable by my RISC OS installation.

Conclusion and next steps

I have a couple theories as to some history here based on everything I’ve found so far.

First theory is that this was cobbled together in the last 20 years, and whoever did it struggled to get it all working. The drive ID configuration would not work in the form I received it and you need a pin to change the external settings, so it is unlikely to be accidentally set the way it is.

Secondly, I think this box may have been hooked up to something other than a RiscPC. The DDS3 drive is a give-away here, I’m not even sure if I can get this running on the machine. The largest I think used were in the 1-2GB range. The fact that the RiscPC can’t read the format of the PD disc would also be an argument towards this theory.

I’ll be tackling things from multiple angles going forward:

1. I have some new belts coming to repair the Cumana drive properly.
2. I need to test the SyQuest drive to see if it can read the disk that came with it.
3. Find a way to read the DDS3 drive if I can. Based on what I’ve read, the TapeFS tool used for tape drives is not compatible with any DDS drive.
4. I have ordered a PCI SCSI card with the same 25pin connector so that I can try these drives on my Pentium 3 PC to see if I can figure out what format everything is in.
5. Once I know what works and what doesn’t I will likely swap out some of the drives to work with the RiscPC.

I’m interested to know what is on the media that came with this kit, could be some development data from a game studio, or could be nothing. Hopefully I’ll find out soon.