I asked this in alt.sys.pdp8, but didn't get the answer, so I will try here: When I got my PDP-8/i (oh so many years ago), it came with a supply of flip-chip spares. Among them are 24 M750s, which I can't find any info about, except the phrase "Line I/O Control". What are they for? They aren't for any of the 8/i's built-in options, so there must be an external option that calls for them? Is there a reason for me to keep so many of the things? Thanks! Vince