Very Computer

When I was trying to install red hat into my old 486, it asked parameter

for the sony cdu-33a drive. I entered cdu31a=0x340,0 but it was not
working. Can anyone help? I have been mess around try to find a
solution.

If you have the CD-ROM working under DOS, look in the autoexec.bat or
config.sys (I can't remember which).  Look for the line that contains SLCD
something or other.  Your CD-ROM parameters should be there.

I had the same problem. Here is the solution directly from Redhat :

It has been found that the options for a cdu31a need some tweaking in the
install. Instead of auto probing for the cdrom, select "specify options". A
screen like the following should appear.

+---------------| Module parameters |---------------+
|                                                   |
| Module options:                                   |
|                                                   |
|   IO base, IRQ, PAS?:     cdu31a=_____________    |
|                                                   |
|   Miscellaneous options:  ____________________    |
:                                                   :
+---------------------------------------------------+

Erase the complete first input line (cdu31a=) and entered the following as
Miscellaneous options:

  cdu31a_port=0x360 cdu31a_irq=0 sony_pas_init=0

If your cdrom is on a Sony PAS

  cdu31a_port=0x360 cdu31a_irq=0 sony_pas_init=1

With these input everything should work perfectly. Auto probing the CD-ROM
drive will usually not be successful, but this might be caused by the not-
too-usual port address setting of the CDU33A.

Good Luck