AS/400

I have an IBM AS/400 9404-F10. These are of the more uncommon variety as they were before IBM moved to the POWER architecture. As such there are not that many still around. This was a midrange machine in the AS/400 lineup.

My machine was made in 1994-1997 (the parts give discontinuity). Compared to the upper models, which were multiple racks of equipment, it is very small. It is considered a "deskside unit" by IBM. I find this hard to believe considering it is twice as long as my desk. A friend pointed out that IBM might just have really big desks!

Pictures

The card cage arrangement is as follows (left to right)

The PDU, this takes the voltages from the power supply from the PSU and breaks it up.

The MFIOP (multi function I/O processor), this card runs the show for the first half of the IPL before the CPU takes over. Then it acts as an I/O processor.

The twinax controller card, this card specifically breaks out into an 8 port connector brick. But I also have a card for two 4 port bricks which instead of one DB-15 connector has two DB-9 connectors.

Communications adapter, this technically is not needed but all the 9404s I have seen have had one installed. It essentially just allows for more communication lines

Blanks. These could be populated with any expansion cards, such as ethernet, token ring or more RAM.

Ram expansion card, this adds up to 24MB to the 8MB already in the CPU card. (8MB in the card and 2 more sets of 8MB in the expansion inserts)

CPU card. The D-shell connectors are for expansion chassis.

Restoration tips

This machine stores about a metric ton of foam in it. If you do happen to pick one up, I would recommend stripping it down to the metal frame and cleaning out all the foam. The worst part is the seal between the PSU's fan and the card cage. The foam will most often fall into the PSU itself requiring the PSU be taken apart. There are also 5 RIFA capacitors which need to be removed as they will smoke when power is applied, unlike other systems these ones need to be replaced.

Links and opinions

Would I recommend this to a collector? 100% NO. Unless you are very seasoned with the AS/400 this is very much the deep end. I made numerous mistakes which caused my life to be much more painful. This was due to inexperience and lack of manuals.

Helpful tools if you do have an AS/400

AS/400 Discord server also linked to Libera.Chat ##ibmi

SRC code finder (be warned that codes can vary from model to model)

AS400 CISC System Builder V1R2-V3R6 Redbook Gives feature codes of cards for CISC machine as well as lots of other useful titbits.

AS400 RISC System Builder V4R3-V5R2 Redbook Same as above but for POWER machines.