Retro addons: Cumana Oscar Parallel Port CDROM Drive

I recently wanted to find an easy way to transfer large files to my Archimedes A3010. In particular the data was on a CDROM image. I therefore wondered if there was a CDROM drive I could use with it. This led me to the Cumana Oscar drive. A drive which appears to be somewhat rare.

Parallel CDROM drives

The initial explosion of CDROM drives onto the market was before the time of USB installed in every machine. Before ATAPI was standardised the typical internal standards were “MKE” which was a proprietary standard and SCSI drives. The “MKE” interface looked like a parallel IDE connection, but connected to a special interface typically found on sound cards of the era.

When it came to external drives, you needed to use the ports found on the computers. For expensive computers you had SCSI, for everything else you had a parallel port. This is where Cumana came in.

Cumana CDROM

If you have ever owned an Acorn computer, you have likely seen the brand Cumana. They were popular manufacturers of drives, particularly floppy drives. But in the Archimedes era they also sold CDROM drives. Typically they were rebranded Panasonic drives.

The following is a news item inside the October 1994 Acorn User magazine.

The Cumana Oscar and Bravo were two different parallel port CDROM drives. The Bravo inside was a SLCD drive, which is another name for an MKE drive. Whereas the Oscar was an ATAPI drive. They were both initially released as a 2x speed drive, but later 4x and 8x versions of Oscar were released. My guess is Oscar drives later gained the same physical casing as described for Bravo, because my drive has a solid metal case. At £229 in 1994 that is £450 in 2023 money, ouch!

My Oscar

The drive I acquired is in pretty good condition, but the driver disk that came with it was not readable in any drive. This led me to finding out how rare this drive was. The model printed on the bottom is 242AP.

It has a parallel port Centronics connector to hook up to the PC parallel port, and a pass-through parallel port to connect a printer or another device to. It also has audio output ports for audio CDs.

Opening it up, we see a Panasonic CR-583 8x speed IDE CDROM drive, a circuit board for audio, one for data and a power supply.

When I found the driver disk was not working, I searched around for it. All the sites I tried had drivers for the Bravo drive, but none had the Oscar driver. As the two are different internal interfaces, the driver software is not compatible.

The good people at CJE Micros supplied me with the correct driver to download, both a disk image file and zip file with the utility. I have made these available on my Downloads page for anyone who hits this problem in the future.

Using the drive

When it comes to using the drive, it couldn’t be simpler. Just load !BootOscar.

This is the icon on my RiscPC. The !BootPSLCD is for the Bravo drive and will not work with the Oscar drive. This will instantly add the CDROM to the system. Here is a RiscWorld CD in the drive.

I believe this drive can also be used on PCs with the “Backpack” CDROM drivers. I have not yet been able to confirm this. UPDATE 2023-05-24: No, these drivers don’t work. The main PCB uses a an Altera chip so it likely uses a custom protocol that would need specific drivers.