Bare microdrive units.

[Dave]

I know a few of you have pulled microdrive units out of your QLs to use SD cards or microdrive emulators instead. I'm looking for a few microdrive units to upgrade/refurb into something next level.

If you'd like your microdrive unit to see a second life doing something next level, ping me and we can sort out a fair price and postage.

[bwinkel67]

I don't have any but I'm curious about the "next level" project. I had a project that's a little beyond my comfort zone, though I still want to give it a go. Basically I wanted to mount a tape head onto a cartridge and see if I could digitally emulate the digital tape and eventually see if it all could be shrunk into a standalone cartridge with like a CR2016 battery or something like that powering it. One of my colleagues did work on a competitor for microdrives back in the 80s (I believe Coleco Adams was working on that and he worked there).

[Dave]

I had an idea for placing a pin header beside the tape head. This would allow a microdrive cartridge to use the bay, and an SD card to use it too. You shouldn't have to give up your microdrives to use an SD card in the same bay.

The SD card would go in a 3D printed microdrive adaptor.

This is on top of my greatly improved microdrive board, which is functionally immune to noise from the QL itself.

Unfortunately, the ULA supply glut dried up so I can only make these from existing working microdrives. If I can find some of the ULAs I can make some from scratch - I have managed to source every other part.

[bwinkel67]

Kind of the same idea but a different approach. I like the feel of original microcartridges. Yours sounds more practical since you just have to integrate an existing SD card interface and make it accessible to the pin header. I certainly like the idea of a microcartridge case that then accepts SD cards, that's why i wanted to create one that just tricked the existing tape read interface to think it was using a tape. The advantage to yours is speed, since my approach would be more in the realm of vDrive where it runs at native speeds for 128K images.

Will your design be modular -- i.e. some sort of 3D printed bracket that places the pin header in an appropriate place and interfaces with an existing SD card interface? The problem with my approach is shrinking it all to fit into a microcartrdige and adding power, but still, if I get help from my colleague, maybe I'll explore it. I would think my initial prototype would have a bunch of wires hanging out...figuring out how to determine reads from writes was the tricky part (we talked about how that might possible work digitally).

[martyn_hill]

Hi Dave!

I LOVE your initiative here - if there is anything I can do to assist in developing/testing your improved MDV headboard design, please let me know.

I may have a couple of spare MDV units and I also have a couple of NoS MDV ULAs, ready to replace failed units.

If it proves easier, I have the means, components and experience to fit-out a couple of headboards myself, if you were willing to send over a sample headboard - as a potentially cheaper alternative to me shipping old units to you...

In anycase, good luck!

[stephen_usher]

For ease of use and longevity, would sprung pins be better than a pin header, with the SD carrier having contact plates onto which the pins press?

As for the ULA, I don't know if anyone has reverse engineered that one. It's probably quite simple.

[Derek_Stewart]

I normally do not use microdrives, as I use QLSD, Drive, Oqtadtive, MicroPicoDrive so from 5 QL I have 10 Microdrive units.

... they sit in a storage box.