Thread by @TubeTimeUS

here's a weird object! it's some kind of foot pedal with an IBM logo. is it for a sewing machine? electronic synthesizer? what do you think? 🧵

it's got a cursed connector! what IS that?

amazingly enough, I found something with the mating connector on it! but what is it?

it's an IBM Executary model 224. basically a dictation recorder. it comes in a fancy leather case with a handle.

to connect it to external power I had to remove the case. let's see if it works.

oh wow it works! the voice is not mine, whoever owned it before me must have recorded this.

normally it runs off this really weird 11.2V battery. but the battery is over 40 years old and is totally dead, although amazingly enough, it hasn't leaked!

(in contrast, i've had brand new duracells leak even before their "best by" date. garbage.)

hey what's this piece of paper rolled up and stuffed in the battery compartment???

it's the maintenance record! looks like it was last serviced in 1980.

to take it apart we push this button on the back.

the cover slides back so you can see the tape!

it's a infinite loop of tape that is quite wide. the head can be moved around with that little lever. normally it is driven by a worm gear.

to remove the tape you push the little catch at the end, and the entire head assembly swings up.

and here is the tape. looks like it's been in the same position for a few years, lol

by pushing a little catch underneath the grey metal cover, you can pull it all the way off.

take out 4 screws and you can access the little rubber belt. they tend to turn into goo, so i am very lucky this one is intact.

the belt is marked "NEUTRIFLEX" and "69017"

i'm trying to make a replacement out of TPU, just in case.

it looks OK and seems to work. at least i have a backup plan now in case the original belt fails.

removing some more screws exposes the electronics inside. there's a lot of point to point wiring, and some lacing tape as well. it's actually pretty messy.

the capacitors appear to still be OK. so that's nice.

no pic, but i found IBM part numbers on the transistors! there are some in plastic packages and others in round metal cans.

it's a pretty cool old gadget. i'll leave you with this picture of the (equally cursed) connector designed to mate with the connector at the beginning of the thread.