IBM 5161 Expansion Unit
Some time back, I acquired an IBM 5161 expansion unit that adds extra capacity to the original IBM PC model 5150. The 5150 only had 5 expansion slots and two full-height 5.25″ floppy drives so it had limited space when hard disks started to appear. The IBM 5161 expansion unit could be purchased with one or two hard disk drives and added extra expansion slots.
The expansion unit was tied to the host 5150 computer through an extender card (in the host PC) and a receiver card (in the 5161 expansion unit). Between the two was a 62 pin cable that transmitted the bus signals back and forth.
The usual Extender card (part number 1501416) is in a 5155 portable computer, in my case. The receiver card (part number 1501426) is in this 5161 expansion unit. Here are some pics. Please excuse the dust. These were the original pictures from the auction.
In addition, I acquired a pair of extender/receiver cards that appear to be newer. I have not yet tried them. The Receiver card is IBM part number 1503902 and the Extender card is part number 1503905.
I will be trying these to ensure they are a proper pair.