IBM 6648 - Manual (Page 143)

CD-ROM drive jumper settings
CD-ROM and PC/CD-ROM drives use jumpers or tabs to set the drives as
primary (master) or secondary (slave). Refer to the drive connector labels or
the figures below for the drive settings.
AUDIO IDE INTERFACE
See Jumper
Settings Below
DC INPUT
R G G L 5V G G 12V 39
40 1
2
CD-ROM Primary (Master) Secondary (Slave)
40X : : : :
48X : : : :
BIOS levels
An incorrect level of BIOS can cause false error and unnecessary FRU
replacement. Use the following information to determine the current level of
Chapter 3. Types 6058/6059/6269/6578/6579 129