PC Enterprises 3.5" PCjr drive

[falter]

Picked this up recently:

https://drive.google.com/file/d/1KUJ...ew?usp=sharing
https://drive.google.com/file/d/1KZD...ew?usp=sharing
https://drive.google.com/file/d/1K_R...ew?usp=sharing

If I understand correctly, you could potentially have three floppy drives in a PCjr. I have two PCjrs - one unexpanded and one with the Quadram memory/floppy expansion unit. I'm thinking it might be difficult or impossible to add this to the latter, given cable length. I wonder if it would work anyway? Looking around for a manual - I assume the jumpers are important.

The two connected PCBs are interesting..

[KenEG]

The two connected PCBs are, I believe, a standard PCJR disk drive controller and an add on that enables it to controller a second drive. It is a different way to do the same thing the Quadram unit does. The tall sidecar of the Quadram unit serves the same purpose. There should be a slot in the bottom of the PC Enterprises for the stacked cards to fit through. It is clearly missing its power supply. You should be able to use a regular PC power supply or build a simple supply to power the floppy drive. The PCJR supply doesn't have enough wattage to handle two drives. I have the controller card to one of these, but nothing else. Someday I need to see if it works.

You should be able to find a lot more information at brutman.com

[falter]

Thank you!

I don't see any evidence of a power supply ever having been there - what I see is a standard 4 pin power supply cable that is branched into a Y. It sort of looks like the intent was to intercept the power connector where it goes to the existing drive, plug the power wiring for that into the Y cable, and then have one end going to the 3.5 and the other going to the original drive.

[KenEG]

You can try it that way, but I think the power supply went in the back left of the case. The narrow opening was where the power switch was and the one that is almost square is where the power cord plugged in. Some of these also added other features like RAM and DMA. Maybe this was a cheaper version that just added the floppy.