The other day I got a Compaq Armada 7350MT sold for parts which lacks the hard drive connector:
Re: Bought these (retro) hardware today

It seems I have the right kind of connector in my parts bin although it was not a Compaq so I can't just check pinout to see what matches. The caddy used by Compaqs seems to be really rare and tough to obtain these days so buying one without the drive was a bit of a mistake. It seems that this 50 pin connector was used in the Compaq LTE series and many of the Armada series in the Pentium and Pentium II era:

Compaq don't seem to have documented the pinout anywhere but I found this: https://old.reddit.com/r/AskElectronics/comme … eige_connector/
That's a single sided flat flex PCB going into the 50 pin HDD connector and a 44 pin notebook IDE connector. Which is great because that means all the traces are visible in this picture.
I am assuming that the Compaq 50 pin IDE connector pinout is unchanged through the LTE series and the Armada series, but I don't see why they'd change the actual pinout since it's only really used to make the hard drive connector survive being inserted and removed many times. (and lock people into buying the Compaq drive packs to get warranty service...)

So I traced them out and it seems to make sense - the pinout is pretty logical:

Here's what I've got so far, the notable differences are that the connector skips the DMA, CSEL and IORDY pins.

Does anyone have a Compaq LTE or Armada laptop and could verify the caddy's connections?