IBM RS/6000 43P-240 specific notes

PrevUp

This machine (running AIX) is the centre piece of my home installation insofar as it is the central file server, i.e. it holds all user file systems and (almost) all application software for all my UNIX platforms. An AIX box is a perfect match for this task, due to its mature JFS and LVM, and ease of administration via SMIT. For this purpose I equipped the box with a second CPU card, a second SCSI adapter and a second 10/100 MBit NIC. External disk space is provided by a DEC StorageWorks tower with 7 disk bays.
The machine now lives its third life. Originally it ran GSI's payroll software (PAISY). After that it served in the Cave A counting room as a control computer for irradiation experiments.

Pixx

Front views:
front view, closed front view, open
Views inside, complete and with disk carrier and media cage removed:
view inside view inside,no disk
The rear side:
rear view

RAM

The DIMMs for models 140, 240 and 150 have FRUs as follows (excerpt from Install & Service Guide (pdf)):
  140 240 150
16MB 42H2772 (1-6) 42H2772 (2-8)  
32MB 42H2773 (1-6) 42H2773 (2-8)  
64MB 42H2774 (1-6) 42H2774 (2-8) 19L1808 (1-4)
128MB 93H6823 (1-6) 93H6822 (2-8) 19L1809 (1-4)
256MB     29L3302 (1-4)
The numbers in parantheses indicate how many of the respective modules can be installed. An even minimum number indicates that the modules must be installed in pairs of equal capacity.

The 43P-240 seems to be extra picky, in particular as far as 128MB RAM sticks are concerned, not all sticks which work in a -140 will also work in a -240. The following (OEM) sticks worked:

Tape drive

The machine originally had a DDS-2 (4/8GB) tape drive, IBM P/N 21H5154, FRU 58H3481, made be Seagate. As usual, it broke after a few dozens of backups. I replaced it with an HP C1537A DDS-3, hoping this will last longer. It also has a much larger capacity (12/24GB), better suited for a file server. An adapter is needed to connect the 50-pin tape drive to the 68pin internal SCSI bus of the 43P-240.
Note that the switches on the HP drive have to be set to be compatible with the RS/6000, as described here. Otherwise the drive will wreak havoc on the SCSI bus. It is also recommended to use the mounting rails coming with the HP drive, they will fit both, the drive and the media cage. The original IBM rail's screw holes don't fit the ones in the HP drive.
To swap tapedrives, one has to remove the whole media cage, unfortunately, but this is not too difficult.

SCSI controllers / SCSI IDs

The machine has two controllers, one onboard for the internal stuff (disk, CD-ROM, tape drive) and the other one as an extra card for the external disk storage. The SCSI ID of the onboard controller happened to be "6", which conflicted with the ID of the new tape drive. Unfortunately I realized that only at boot time, when this clash sent the box in an infite loop.
Remedy in this case:
  1. on boot press F1 as soon as the keyboard symbol appears on the screen. This will get you on the SMS menu
  2. Choose Utilities - SCSI ID
  3. Choose Default and Save, this will reset to ID=7
  4. It could be the bootlist is corrupt.
    Go back in the SMS menu (or reboot with F1 pressed as above), choose Boot and Change Bootlist. Use the Page Up/Down keys to navigate through the list in case it's longer than the screen can display.
    Choose the appropriate boot device and reboot.

Last updated: 16-Jun-2012, M.Kraemer