osiweb.org

I've asked on the Facebook Flashfloppy Gotek page about OSI support.

https://www.facebook.com/groups/flashfl ... 6684910565

I'm a little out of my depth so if anyone wants to join the conversation...it would be great to get a solid state floppy emulator working with our machines.
Realistically, how much longer can out floppy media last???

Phil

How is the progress with this Phil ?

Dave is looking at getting some Kryoflux dumps.

I have ordered a new kryoflux, as mine seems to have some issues (I was warned it may have problems when I got it.) I also got an adpater and parts for the 8" drive 50-pin cable, so I can hopefully make an 8" image as well.

Shame the original Kryoflx didn't work. Is it beyond repair?

Phil

Not sure if it is repairable. It's definitely quicker to replace than repair.

Hi all,
I've been looking at the Gotek floppy emulator and others for a while as an Amiga floppy drive, but the messages here piqued my interest so I decided to finally get one after looking at the FlashFloppy firmware project. Originally I didn't realize how many formats it supported, but it does already do FM emulation. I was able to set up the build environment and compile the current FlashFloppy source. I was also able to dig through my junk box to find some old parts to convert the pin header interface to an edge connector used on the 34pin 5.25" floppy drives. My C4PMF setup already has a data separator inline with two external PC 1/2 height drives, so I should be able to simply plug in the Gotek and go.

I believe I can encode an OSI dump image into an FM bitmap at least for OS65D since the disk layout and timing is known. Formats like hexdos should probably convert fine too since they're based on the same layout. It's all 8E1 serial data with a clock bit before every data bit. The FlashFloppy firmware already handles the correct I/O timing for 5.25" drives (and 8" more or less).

So I still have to do the initial conversion on the gotek drive. I have the PL2303HX cable ready.

The first step after getting the Gotek and OSI talking is to build an FM image FlashFloppy is happy with, or putting the code in the FlashFloppy file loader which is where it'll go eventually anyway. That should get read operations going, write will be a bit more tricky, especially back to OSI disk image format.

My long term goal would be to output separated clock & data since that is what the drives in real OSI machines do. On 5.25" drives I believe OSI uses pins 30 (normal Read data) for Clock, and pin 34 (normally Disk Change) for Data. Pin 34 is an output controlled by the gotek CPU according to the schematics I've found, but it is on a different port. I haven't looked deep into the inner workings of the firmware code/DMA etc. so I'm not sure if the data rate is sustainable on that I/O pin, but separating clock & data halves the bit rate out of the Gotek.

8" drives should work too with some tweaks. Physically connecting the Gotek to the 8" interface is probably the most tedious. A conversion board would probably make the most sense long term. FM data separation was a lot more common on 8" drives, I think Gotek would have to output separated clock and data to replace an 8" OSI drive.

Anyway, lots of things going on.
Cheers,
-Mark

Hi Mark,
Very excited to hear your thoughts. I will be following with much interest.
As for the conversion from 50 to 34 pin, you may want to look at the fd50to34 board that can be ordered cheaply from Oshpark...I have a few and they work well and keep things very tidy:

https://oshpark.com/profiles/NF6X

Please keep us up to date with any progress, and good luck.

Cheers

Philip

Thanks for the oshpark link. I have an 8" drive and that looks like just the thing for it. See there are some other interesting boards there too. Like the Gate array eprom adapter and CoCo Cart board Looks like I'll be ordering some board......


David

I finally created a couple of raw dumps (5.25"), and just posted to the facebook group for further guidance. Let's see what happens.