VOGONS


First post, by AB75

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So I have a Gateway 2000 486 DX2 66Mhz I bought new in 1993. It came with a Sony CDU-33a cd drive.
In the manual it says that newer models (the one I have) would come with the CDU-33a, not the previous
CDU-31a. Anyway, I remember it came with several CDs. So, I hook up this thing after 15 years and it works perfectly.
The cd-rom, soundcard settings still in the original working AUTOEXEC and CONFIG files, no errors during boot up.
The strange thing is, all the CDs I have from 1993 are in perfect condition and read fine one other systems
I have tried, older and newer. On my old 486 however, all except one are unable to be read. When I insert this one particular CD,
I can go through all directories and run the disc fine. All other discs however, I get "Not reading drive E:" when inserted.
I have tried many different settings and configurations as well as MSCDEX versions and all yield the same result:

replacing CDU-33a with several working condition drives from ebay.
replacing all cables (this was pointless as the cdu-31a works perfectly with these cables)
replacing several working soundcards with 34 pin interface to connect to cd-rom
using working soundcard with no 34 pin interface and using working cd-rom controller.
various CONFIG/AUTOEXEC edits (I am still familiar with DOS and have tried every IRQ,DMA setting, using QEMM/MEMMAKER etc.)

Now, I then bought a Sony CDU-31a from ebay and with my current AUTOEXEC/CONFIG files,
the cd-rom plays every disc perfectly with the rom drive connected to the 34 pin interface of the soundcard
as well as only connected to a separate controller card.

So as having literally trying every solution to get the CDU-33a to work with every disc, I still don't understand how
a cd-rom drive can only play one disc and not any others all from the same era and known to be working. I don't remember if these
CDs played on the 33a back in 1993, just discovered this recently. Normally, I would never put this
much effort into something like this, its just the fact that only one disc plays on it blows my
mind. Thanks.

CONFIG.SYS:

Lastdrive = E
Device = C:\DOS\setver.exe
Device = C:\DOS\himem.sys
DOS = HIGH
Files = 50
Stacks = 9256
Device = C:\SB16\DRV\csp.sys /P:220
Device = \DEV\slcd.sys /D:Sony_000 /B:230 /M:P /V /C

AUTOEXEC.BAT:

@ECHO OFF
C:\DOS\smartdrv.exe
prompt $p$g
PATH C:\WINDOWS; C:\DOS; C:\MACH32
SET TEMP = C:\DOS
COMMAND
SET BLASTER = A220 I10 D1 H5 P330 T6
SET SOUND = C:\SB16
C:\SB16\SB16SET /M:220 /VOC:220 /CD:230 /MIDI:220 /Line:220 /Treble: 0
C:\SB16\sbconfig.exe /S
C:\BIN\mscdex.exe /D:Sony_000
lmouse

Reply 1 of 6, by Mau1wurf1977

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Firstly, great first post! Very detailed and lots of information 😀

I'm just having a wild guess, but have you tried cleaning the laser / lens? Or cleaning the drive mechanism inside the drive? There is also usually a dial for calibrating.

It could just be that the disc, that works, somehow reflects the laser differently enough to work.

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Reply 2 of 6, by elianda

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I use the CDU-33A for two 386 systems and the drives work really well. They have problems though with newer CD-Rs, but that's an issue most old CDROM drives have.

I use SLCD.SYS 1.74d / MSCDEX 2.22 (which came with MS-DOS 6.00).
SLCD.SYS /D:CD1 /B:360 /C /K
MSCDEX.EXE /D:CD1 /M:10 /E

I think the default setting on the controller card is port 320.

Have you tried using a different port than 230 ?
Have you disabled IRQ/DMA usage?

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Reply 3 of 6, by AB75

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Wow, thanks for the quick response all. Yes, I did take apart one drive (33a) and cleaned the lens with a little rubbing alcohol, same result. I mean the drive was clean anyway. The 486 sat in plastic in a box in a clean environment (no smoking, cool temp, etc...). The hard drive has no bad sectors after 21 years. Also worth mentioning, the discs I mention are not CDRs, they are discs that came from Gateway when I bought this PC in 1993. The one CD that is able to be read with the 33a is "The Time Almanac 1990". On any other disc with the 33a, when I boot to C:, I insert a disc and then go to E: and when at the E prompt, user dir command and get the reading error. I have used both the Gateway SoundBlaster 16 install diskettes as well as the SoundBlaster 16 MCD install diskettes which came bundled with the soundcard and cd-rom drive. I also have a cd-rom controller that came with another cdu-33a drive. And yes, on the controller its port 320, and I have tried every IRQ, DMA setting and various ports (both on the soundcard as well as on the controller) and this one disc is only able to be read. But when I swap out and insert the 31a, whether the cd-rom drive is attached to the soundcard or attached to the controller, all discs are able to be read normally. I even ran the test that comes with the sound card software and no errors are produced with the 33a attached, as sound is output. I have not tried to disable DMA/IRQ. I wasn't sure that was possible as I thought a cd-rom and sound card always needed an interrupt. I did set DMA to 0, not sure if that's an actual channel or null, but it also worked with the 31A. Also, I have no conflicts as I have no printers or scanners or fotomans attached either. Also, I should of mentioned, I have tried both MSCDEX 2.20 and 2.21. The system came with DOS 6 and Windows 3.1, and I upgraded the ram to 64MB, and also tried this with MS-DOS 6.22. I just wish I could remember if the 33a worked with all these discs back in 1993. Thanks all.

Reply 4 of 6, by elianda

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DMA 0 is a valid DMA channel, however for simplest setup I recommend to remove all jumpers from IRQ/DMA on the controller card and just leave PORT. The driver should show something like "High-speed software transfer mode" then. CPU usage on reads will go up, but it will still reach 2x speed. So for DOS it is not as relevant.

Still I doubt that this solves the problem, where the drive can read one disc fine and doesn't read another one. This seems to be quite odd as the drive already works.

You could double check this by cloning the questionable CD-ROM to a CD-R that is compatible with the CDU-33A. But since those early CD-Rs are rare to get (dark green AZO) it's probably not worth it.

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Reply 5 of 6, by AB75

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One thing I was thinking of trying was installing Win 95 from the 31a, and then swapping out the 31a for the 33a and see if I can then access the drive. After that, yeah, I give up. I'll stick with the 31a, which I believe is 1x.

Reply 6 of 6, by AB75

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UPDATE:

Fresh install of Win 95 successful. 31A drive reads all discs fine. Swapped out 31A for 33A and the
same exact issue happens. Also, before the Win 95 install, I installed MS-DOS 6.22 again and tried
this version of MSCDEX with same result. I'm done and sticking with the 31A. Thanks all.

Adam