Silent Q

Posted By azog on July 31, 2012

Since I do not (currently?) have Internet access directly on my Falcon, and a floppy disk simply doesn’t cut it any more, the benefits of a CD-ROM should be patently obvious.

There are at least two different methods to attach a CD-ROM to the Falcon, using either IDE or SCSI.

The IDE solution is undoubtedly cheaper, but without re-casing the Falcon, attaching one would be a real hack indeed. You’d need an IDE cable with a 2.5″ plug for the Falcon, and one 2.5″ tap for the internal drive, as well as a 3.5″ tap for the CD-ROM. Then you’d need to bring that outside the Falcon box, and have attached to an externally powered CD-ROM. Messy.

The SCSI port is already external, so it’s easier to use, except for the fact that it seems SCSI CD-ROMs aren’t as common or cheap as as IDE versions. I eventually found an old Sun-4 unit at a price I was willing to pay.

Connecting it is fairly straight-forward. I did not have a SCSI terminator plug, so I figured to just give it a shot and see. Luckily, the CD-ROM works without a terminator. Not sure if that was just dumb luck, or if it’s really unnecessary. Or perhaps it’s something as simple as having only a single device on the chain. Be that as it may…

I have HDDriver installed, but it needed a bit of reconfiguration to recognize the SCSI device. The Falcon has two device busses, SCSI is bus1 and IDE is bus 2. The devices are noted in dotted format: device 1.0 is the first SCSI device, and so on. Device 2.0 is first IDE device. Some software will simply sequentially number the devices instead: 0 thru 7 as the IDE, and 8 thru 15 as the SCSI. I have to consider this type of translation later…

I enabled all the SCSI IDs, Just In Case. Otherwise, I’d need to go back in and enable them later, if I decided to add another device or change the ID number. Install the new config and reboot, and now it recognizes the SCSI device. Now what? When I try to “Add Devices”, a new icon does not appear.

I don’t understand how this whole thing works, but apparently HDDriver simply presents the SCSI layer to the OS, and then you need another driver to actually access it. Turns out this is a fairly common issue, and searching quickly gave direction.

There are a few options. One is a commercial product called ExtenDOS, which I may look into later, but for now, I found something called SPIN. Just google for “atari spin” and you’ll find links. I don’t want to link something that could potentially decay rapidly.

It’s a self-extracting archive, just extract it to a folder, look at the README. Basically you need to move everything to the AUTO and edit the CONFIG.SYS file, but it’s pretty straight-forward.

MetaDOS reads CONFIG.SYS to load the drivers. Not sure what the differences between a BOS and an XFS driver is. But here is my CONFIG.SYS for a single CD-ROM at SCSI ID 6.

SPIN_SD.BOS is the spin driver. The letter A is unrelated to GEMDOS devices, I guess they’re just sequential letters. The number 14 is SCSI ID 6 (0-7 is IDE, and 8 thru 15 is SCSI, and the SCSI controller is SCSI 7 or ID 15).

ISO9660F.DOS is loaded and identify the GEMDOS device, S to be connected to SPIN device A.

Once you reboot, if everything is OK, you’ll see MetaDOS loading and connecting the SPIN driver then the ISO driver.

NOW you can use GEM to add devices, and a new drive letter S should appear.

I plan to explore MiNT soon, but I think before I do that, I really want to look at ExtenDOS. It’s more recent than SPIN, has a graphical installer, and appears to support MiNT loadable device drivers.

Category: Retro computing
Tags: Atari