Toshiba CDROM

picture (42 kByte): Toshiba with external case picture (77 kByte): Four Toshiba in a PC case

Not many CDROM drives work on a Sun3. One of the rare exemptions is the Toshiba 3401. The trick is: The drive must be modified to use 512 byte sectors instead of 2048 byte sectors. The Toshiba 3401 does have two solder pads on the bottom of the controller board.

The drives shown here had no case and no chassis, only the naked drive and the controller board. Heiko Krupp saved a hundred of them from the trash. Well, if you collect old computers you stop wondering what other people throw away.

To "insert" a CD into these naked drives, you need a metal ring which centers and holds the CD on the spindle. I use the tin rings of worn 3.5" disks. I tear off the plastic disk and remove some metal rest at the middle hole with a screwdriver. Then i put a CD onto the drive and the tin ring on top of it. The spindle is magnetic and it pulls the tin ring towards it and thus the CD is fixed and centered in between.

The second picture shows four Toshibas in a PC case. To access more than one CDROM drive on the same SCSI string, you have to modify the kernel. SunOS expects only one CDROM with SCSI-ID 6. Obviously sun was forced to do so because the CDROM driver doesn't like tape devices (it simply hangs here). But if you want CDROM drives and no tape drives, make the following modifications to the kernel config file:

controller      sc0 at vme24d16 ? csr 0x200000 priority 2 vector scintr 0x40
tape            st0 at sc0 drive 040 flags 1
tape            st1 at sc0 drive 050 flags 1
tape            smt0 at sc0 drive 050 flags 3
disk            sr0 at sc0 drive 060 flags 2
disk            sr1 at sc0 drive 050 flags 2
disk            sr2 at sc0 drive 040 flags 2
disk            sr3 at sc0 drive 030 flags 2
disk            sd0 at sc0 drive 000 flags 0
disk            sd1 at sc0 drive 001 flags 0
disk            sd2 at sc0 drive 010 flags 0
disk            sd3 at sc0 drive 011 flags 0
disk            sd4 at sc0 drive 020 flags 0
disk            sd6 at sc0 drive 030 flags 0

Tip: CDROM drives from Plextor have a jumper (usually called Block) to switch from 2048 byte blocks to 512! These drives can be used on a Sun3 without voiding the guarantee.

New driver: The CDROM driver of SunOS 4.1.1 cannot handle the rock-ridge extension (ISO 9660). Heiko Krupp does have a modern CDROM driver for the Sun3 on the Sun3/3x-Archive.

Copyright 1999-2007 Peter Koch