Commodore 64 1581 .d81 disk image support?

[fzdravko]

Any chance for Commodore 1581 .d81 disk image support?

Thanks.

[keirf]

Tentative yes but depends as I thought 1581 had a custom serial interface to the c64 and the Gotek would not really be physically compatible?

[fzdravko]

Yes, it has custom serial interface for connection with c64, but internally 1581 have plain 3.5" floppy drive and connection to it (like amiga...).

P.S. I also have usb HxC Floppy emulator and it is working with 1581.

[keirf]

Oh I'm thinking of 1541 with custom formats and different internal drive interface. Do you have documentation for the d81 image and physical track format?

[fzdravko]

No, I don't, but I found this https://ist.uwaterloo.ca/~schepers/formats/D81.TXT

Also on HxC forum there is a mention that D81 is nothing special: http://torlus.com/floppy/forum/viewtopic.php?t=531

[keirf]

Okay please try the following firmware:

ff_132_1.zip

[fzdravko]

I tried it but it doesn't work. Just says "file not found".

[tomse]

Now that the issue is up, I guess the GOTEK isn't powerful enough to actually act as a 1581/1541/1571 drive which can directly be attached to the IEC port.? instead of having a shugart/pc interface port with the 34pin connector, i.e. pins 1-5 can be used as the serial/iec interface instead.

Sorry for the hijack I'll open a new issue if required.

[fzdravko]

Is the starting head possition selected by FlashFloppy firmware or 1581 operating system? I see that on Amiga starting possition is 40:0 and on 1581 is 39:1 (on HxC is also track 39 but on their software isn't show which head 0 or 1).

[keirf]

Are you sure the Gotek is connected right?

[Squirrel61]

@tomse I guess you're talking about sd2iec or similar solutions? In other words, it has already been made. So it's perfectly doable, but a waste of @keirf 's precious time. And besides, I think it would be an "either-or" solution, because I guess it will be impossible to have the Gotek support both the IEC bus and the normal floppydrive bus at the same time. I'm already wondering with al the additions @keirf is making, when the Gotek will be out of flash memory.

[tomse]

@Squirrel61 yes similar to the sd2iec, but where sd2iec isn't 100% compatible, far from it, a cheap and better solution could lie in a gotek. Yes there is also 1541 Ultimate which is close to 100% compatible this one doesn't support d81 files though.

If it's a waste of Keir's time only he can judge that.

[fzdravko]

@keirf Yes, it's connected right.

[keirf]

And jumpered right? I don't know whether you need a jumper at JC (selects PC style interface rather than Shugart). Also S0 vs S1 for drive select. Do you see the green Gotek led flash on drive activity? Do you see the track number change as the drive heads are driven by the host?

[fzdravko]

I didn't change any jumpers, will try that later. When 1581 and gotek are on and image file selected, when I restart c64 (turn off/ turn on) tracks go to 0 and then to 39:1. When command for dir is issued, error "file not found" is immediately shown, it doesn't even try to read.

I will try with different jumper config later today.

[keirf]

Actually I suspect the jumper configuration is fine, interface is Shugart which is the default (no jumper at JC). Also probably drive-select 0 is correct, so jumper at S0 only. I guess this is what you already have. Now I am suspecting the track layout within the image is different than what I expect. Let me check that,,,

[pdp11user]

The Commodore 1581 controller needs ready at pin 34 and drive-select 0:

interface =shugart / jc = open DS 0

Hope that helps!

[keirf]

Okay, looks like side ordering is flipped in a D81 image. Here is a new firmware to test:

ff_132_2.zip

[fzdravko]

It's working now.

Thank you!!!