This page is about fitting an older PC with a CD-ROM drive. There are basically three types: Newer ATAPI drives, for computers from about 1994 on; older IDE drives with proprietary interfaces; and SCSI drives.
Older CD-ROM drives come with a special adapter card. If you have this,
installation should be unproblematic, too. You will find only single
and double speed drives. It's not as bad as it sounds, double speed is
fast enough for any DOS game that plays from the CD, even the latest
ones. The single speed drives can be opened with the power off and
are really my favorites.
Soundblaster 16 cards, and many compatibles, have a CD interface. If there is only one, it can only be used for a Panasonic drive. The driver is cdmke.sys, the line for the config.sys is:
DEVICE=\DIR\CDMKE.SYS /D:CDROM /SBP:220 /S:A
assuming your soundblaster is set to I/O port 220. DIR is the directory where you put the driver, /D is the name you give the drive and can be anything, the /S parameter can be set to N (single speed), D (double speed), or A (automatic). In automatic mode, the drive will play audio CDs at single and data CDs at double speed—the way it should.
There are two Soundblaster 16 cards with multi-CD support and interfaces for Mitsumi, Sony, and Panasonic drives. With the older CT1750/CT1759 you can set the port and the IRQ for the Mitsumi interface via jumpers:
Port address: 310 320 [340] 350 JP18 ON OFF ON OFF JP19 ON ON OFF OFF Mitsumi IRQ: 3 10 [11] JP20 OFF OFF ON JP21 OFF ON OFF JP22 ON OFF OFF
On the later CT2230/CT2239, only the IRQ is set. Obviously the CD is supposed to share the sound port, but I could never get this to work. As I found out later, a seperate driver is needed for the soundcard. This makes this setup not a very good idea. You tend to run out of memory more often than you run out of free slots.
One problem with these old drives is that they sometimes cease to work without apparent reason. I had built one into a 386, and it worked fine. Then I found and installed a Tekram cache controller, and suddenly the drive ceased to work properly. The driver still found it and a letter was assigned to it, but when I tried to actually read from a CD I got an error message you usually get when the CD is damaged. The drive and card worked fine when I put them into another computer, so there was nothing wrong with them. It was like some sort of resource conflict I could never fathom. Even when I took the cache controller out again nothing changed. It seemed there was simply no way I could have a CD in this computer.
Nor was this an isolated incident. I encountered exactly the same behavior when I put such a drive in one of my favorite computers, a 286 with an on-board hard drive controller. Again, the drive would be assigned a letter, but I could not read data CDs. Nevertheless I left it in, since it worked fine for playing audio CDs. Yes, even all the software CD players worked. Now imagine my surprise when I tried once again to read a data CD after a long pause and it worked like a charm. It was, as we say here, an astonishing case of voluntary self-repair.
I have no explanation for any of this, not for the sudden cease of function nor for the resuming. All I can say is: If it doesn't work, don't give up. Maybe it just will some day.
When run under DOS, SCSI offers no real advantages. It is faster only under multitasking operating systems. But SCSI cards are easier to find than cache controlers and might be an option when you want to equip an older computer with something faster than a double speed drive.
You will need two drivers, one for the SCSI host adapter and one for the CD-ROM drive. In many cases, a generic driver for the latter will do. Example, with an Adaptec AHA-1540CF card:
DEVICE=C:\SCSI\ASPI4DOS.SYS /D DEVICE=C:\SCSI\ASPICD.SYS /D:SCSICD1
Invocation of the MSCDEX/NWCDEX in the autoexec.bat is pretty much the same as with an IDE or ATAPI CD-ROM.
Generally unproblematic, but can be used only with motherboards whose BIOS supports this. Unfortunately, there is no real telling which boards do and which do not. The oldest I have found up to now are PS/1 and PS/Valuepoint motherboards with a BIOS from September 1993. The oldest drive I have found is from September 1994. It bears the strange inscription Double Speed Friendly™ on top of the case.
Under DOS, a generic driver should work with all brands. I, personally, prefer the oakcdrom.sys found on the Windows 98 startup disk. If you have more than one CD-ROM drive on your computer, it will assign a different letter to each.
If the BIOS of your motherboard does not support CD drives, you can still use one if you find a cache controller with CD support, for example the Tekram DC-680 CD.
The great advantage is that you can use any drive you want. Drives from 1998 on and later can read CD-RWs, however, DOS drivers can't.
No DOS driver yet is able to read CD-RWs (CD-Rs are no problem, if the drive can read them), nor CD-Rs above a certain size, which I couldn't figure out exactly yet. Possibly it's 512 MB. It is a wise idea to make installation of the CD-ROM drivers an option (prefix the line in the config.sys with a ?), since they will always use up some conventional memory and should only be installed when necessary.
Some CD-ROM drives require a caddy, which is sort of like a removable tray. The idea was to give the CDs a protective casing so you never had to touch them again, avoiding the risk of smearing and scratches. Of course this only worked if you had a caddy for every CD in your collection. This may have seemed a good idea when CDs were few, and mainly expensive databases. But the price of CDs was decreasing rapidly. The latest caddy drive I have yet seen is a Yamaha CD burner from 1997. Caddies are cheap, but difficult to find, most people probably threw them away. Except for curiosity, stay away from these drives.
| 1992-03 | 1 | 1h |
| 1993-05 | ||
| 1994-04 | 2 | 30min |
| ATA | ||
|---|---|---|
| 1994-09 | 2 | 30min |
| 1995-09 | 4 | 15min |
| 1996-07 | 8 | 7m30s |
| 1998-03 | 24 | 2m30s |
| 1998-08 | 32 | <2min |
| 1999-09 | 44 | 1m20s |
| 2000-08 | 52 | 1m10s |
| 2000-10 | 50 | 1m12s |
It is interesting that 16× drives seem to be comparatively rare, I have never seen one, while both 8× and 32× are quite common.