Outside development welcome?/Source Code available?

[Jman]

Wow! Here I thought I was only one in the world that wanted to emulate floppy discs from an "alternative" device

I have an old machine (Varian SpectrAA 10) that uses 5.25" floppy to run. I used 3.5" to keep it running for a while but the 3.5" drives do not work reliably (only 1/20 drives I try work 100%) so, instead of fixing the 3.5", I want to emulate the drive with PIC (much like the stand-alone HxC SD floppy emulator).

The format of the disc is unknown at this point (Previous 3.5" mod didn't require knowledge of disc format). I am yet to discover this. From what I understand the HxC SDFE will probably be able to read custom formats but not write. I need to write also.

I am determined to give read and write ability to HxC SDFE for my disc type and will be grateful for the opportunity to contribute to the project.

My question is, will I be able to get the HxC source code for PIC so I can program write capability?

Thanks for your time and for contributing this wonderful project!

Regards
JMan
South Africa

[Jeff]

Wow! Here I thought I was only one in the world that wanted to emulate floppy discs from an "alternative" device

I have an old machine (Varian SpectrAA 10) that uses 5.25" floppy to run. I used 3.5" to keep it running for a while but the 3.5" drives do not work reliably (only 1/20 drives I try work 100%) so, instead of fixing the 3.5", I want to emulate the drive with PIC (much like the stand-alone HxC SD floppy emulator).

The format of the disc is unknown at this point (Previous 3.5" mod didn't require knowledge of disc format). I am yet to discover this. From what I understand the HxC SDFE will probably be able to read custom formats but not write. I need to write also.

I am determined to give read and write ability to HxC SDFE for my disc type and will be grateful for the opportunity to contribute to the project.

My question is, will I be able to get the HxC source code for PIC so I can program write capability?

Thanks for your time and for contributing this wonderful project!

Regards
JMan
South Africa

No the code source are not available, but which FDC are used in the Varian SpectrAA 10 ?

[Jman]

No the code source are not available, but which FDC are used in the Varian SpectrAA 10 ?

The FDC is an Intel 8272.

I am going to try Image Disk now to see if I can extract the disk image.

[Jeff]

No the code source are not available, but which FDC are used in the Varian SpectrAA 10 ?

The FDC is an Intel 8272.

I am going to try Image Disk now to see if I can extract the disk image.

Intel 8272 is an MFM (DD) / FM (SD) floppy disk controller, so Image Disk should be able to read these disk without problem.
If these floppies use the MFM (DD) format, the emulator already support the Varian SpectrAA 10 in Read and Write mode.

[Jman]

That is good news.

Image Drive hints that the FDC is using DD. I get lots of read and interleave error though.

Would it be possible to create an unformatted floppy image on HxC FDE then allow the machine to format it?

[Jeff]

That is good news.

Image Drive hints that the FDC is using DD. I get lots of read and interleave error though.

Would it be possible to create an unformatted floppy image on HxC FDE then allow the machine to format it?

Yes, With the windows software, use the "Load Raw Image", set the good geometry (sector size, number of sector per track, side , number of side...) and press the"Create Empty Floppy" button.
After this you can export this empty floppy to a hfe file.

[Jman]

That is good news.

Image Drive hints that the FDC is using DD. I get lots of read and interleave error though.

Would it be possible to create an unformatted floppy image on HxC FDE then allow the machine to format it?

Yes, With the windows software, use the "Load Raw Image", set the good geometry (sector size, number of sector per track, side , number of side...) and press the"Create Empty Floppy" button.
After this you can export this empty floppy to a hfe file.

Ok I might still have a problem then because I do not know yet what is the good geometry. Image disk gives 9 sectors, 300 rpm, 512 sector size, 250 kbps, 2 side and I guess it is 40 tracks but still get lots of errors. Are errors normal for strange disks?

[Jman]

Also I am wondering if PIC18F4620 will work in place of PIC18F4525? I etched the PCB today but my supplier does not have 18F4525

[Jeff]

Also I am wondering if PIC18F4620 will work in place of PIC18F4525? I etched the PCB today but my supplier does not have 18F4525

Yes this works.

[Jman]

Ok thank you for the assistance Jeff.

Im very new to world of floppies but I think maybe there is hope that I'll get it working . I analysed the images from Image Disk, I can see from the ASCII data that some correct data is being captured but with problems. Data will repeat within same sector and at nearby sectors (even nearby track). Very tricky for me to visualize what is the problem.

I noticed my FDC fails FDC test for 128 sector size. Maybe this is the problem. I report back if (when ) I find the answer.

[hesaan]

Hi I too have a Varian spectraAA 10 that I would love to set up, but no software. The machine won't boot up without it! Would it be possible to get hold of this in whatever format works.