Mike's PCjr Page

Hi,
I'm very interested installing one of these. I noticed that there are different ones.
I want to use 3.5 720kb flash drive, or is there a better set up that I don't know about?

I'm clueless about these.

Any help would be appreciated!

Paul

I'm just getting into these now, so here's the best of the info I have right now.

The Gotek units are all set up for a specific drive they are emulating (e.g. 3 1/2" 720k, 3 1/2" 1.44MB, etc.) and I believe that pretty much has to match exactly the type of drive you are replacing (it's hard coded in the Gotek firmware).

I am currently using a Gotek unit that has had it's firmware replaced with FlashFloppy which to my understanding removes this restriction. I have testing the one I have as a replacement for my 5 1/4" HD drive and am testing out using it to replace the main 5 1/4" DD drive. It seems to work for IMG images, but I am having issues getting HFE images to work for a DSDD disk. IMG would work for most things, I'm just interested in HFE as it will allow me to preserve any of my disks that have copy protection on them.

HxC also has a firmware update for the Gotek units but I'm not all that familiar with how well it works.

Did the PCjr ever support 3 1/2" disk drives? I was only ever aware of 5 1/4" DSDD and DSHD.

You could always look into a jrIDE if you want to hook up a compact flash card, or there is another project for an SDcart to read SD cards from the cartridge slot.
https://www.retrotronics.org/home-page/jride/
https://texelec.com/product/jr-ide-for- ... rotronics/
(Note, I believe I saw someone mention on these forums some work on a rev C to the jrIDE, however I don't know the details.)

https://www.raphnet.net/electronique/sd ... cLbGQKdLd4

No insight on the GOTEK specifics, but a 3.5" drive will run on the Jr:

• Only the double density data rate is supported, as that comes from the controller.
• The BIOS thinks it has a 360K drive because the BIOS thinks that all floppy drives have 2 heads and 40 tracks.
• DOS is actually smarter about the drive parameters, and will override the BIOS. This is due to the magic of the medial descriptor byte in the boot sector of each diskette.
• DRIVER.SYS can be told to create logical DOS drive letters that have the expected geometry.

So, while technically not supported it works. I've tested with a lot of 1.44MB drives and all of them have worked. (If a drive didn't work, it turned out not to work in other systems as well.) You have to use double density media though; using a 1.44MB diskette will not be reliable because the media is different.

I need to get a GOTEK ...

I have a Gotek that I flashed with HXC and it works great on the PCjr. The PCjr read/writes both 360k and 720k disk images with no issues. I added an OLED screen that is much better than the stock LED display.

http://hxc2001.free.fr/floppy_drive_emu ... reForGotek

PNKlett wrote:Hi,
I'm very interested installing one of these. I noticed that there are different ones.
I want to use 3.5 720kb flash drive, or is there a better set up that I don't know about?

I have a Gotek I bought off Amazon, and I put the https://github.com/keirf/flashfloppy firmware on it, and it's working great in my PCjr. I've only used 360k floppy images on it so far though.