Gotek 800k disc images!

[retrogamer]

I have extended the functionality of my Gotek (set as Drive 1) with 800k double-sided 80-track disc images.

I've been swapping discs frequently in project work involving both Zen and Basic and the discs have soon filled with COM, OBJ, XBS and other such files. More space should help minimise this incessant swapping!

I recommend using DOS80 V1.0 (System 80 - 1986) as it has a configuration tool to set Drive 1 to 80 tracks. Run CONFIG and follow the prompts to set each drive to single/double sided with either 40/80 tracks as required. CONFIG then saves the modified system tracks to your boot disc in Drive 0 so this step is not required again. BACK80 confirms how your system is configured every time you format and backup.

XtalDOS 2.05 (System 5 Plus - 1987) also works fine but you'll need to patch the disc using MOS (see the manual) if you want 80 tracks on Drive 1 as the default is 40 tracks.

I've not yet found or been able to generate an 80 track DSK image that would verify. CPCDiscXP can generate over 20 formats but none have 10 sectors per track with appropriate numbering for the Einstein.

Turns out a DSK image wasn't critical as an empty HFE image worked a treat with FlashFloppy! I used an image (double_density.hfe) from the FlashFloppy GitHub.
https://github.com/keirf/FF_Images/tree ... /Empty/HFE

The image is not formatted so you'll need to use BACK80 to format up to 790k Total with 128 directory entries on the Einstein. Once created, you can copy this formatted image to easily generate new discs as required.

I've used VERIFY.COM (my version is V4.0) by typing VERIFY *.* to check the integrity of all the files created.

Only downside I can see is that you'll need a DOS reboot (with a XtalDOS 1.3 boot disc) to go back to accessing normal DSK images on the Gotek!

Have fun

Richard

[Lardo Boffin]

Very interesting thanks.

I was looking at System 80 as it suggests that it is a bit faster and when compiling C faster disc access is a bonus.

My gotek is plugged into my external drive port but boots as drive 0 (the power is disconnected to my physical drive 0 so it is ignored) - any idea if I will still be able to do this?

Using HFE images is a great idea! I had to use these on my beeb to save Action Replay files to gotek.

[retrogamer]

Don't foresee a technical problem with booting from a Gotek with an 800k disc.

But with only one drive set to a different format, you'll not be able to access any normal DSK files so copying from one format to another on the same drive will not be possible

That's why I set the jumpers to configure my Gotek as Drive 1 so I've got two drives with both formats concurrently accessible.

If you really want to keep your Gotek as a replacement Drive 0, perhaps you could use a cable to connect two Goteks externally! Drives 2 and 3 default to 80 tracks under System 80. You'd need to set the jumpers to configure a second Gotek with a different format as an additional drive. See https://www.tatung-forum.co.uk/viewtopic.php?f=3&t=84 for further information.

Yes, the formatter includes sector skewing so it has a faster access time on a physical disc (up to twice as quick - see the review in Einstein User December 1986). I saw the skewing with a low level HFE disc editor when I checked the sector ID information after formatting. Fascinating to see the physical properties of what is actually a non-physical disc.

If you want to try for even more speed, there's an empty HFE in the same folder on GitHub that looks like it spins a fifth faster than the usual 300rpm (it has the 360 suffix)! I've no idea if rpm actually affects the operation of FlashFloppy, but it might be worth investigating

Richard

[Lardo Boffin]

At the moment I only have one gotek. My tatty does have a physical drive 1 installed. Could I boot:

Drive 0 gotek 800K
Drive 1 normal 3” floppy

Also would it be possible to post a blank 800k image please? Would be greatly appreciated!

[retrogamer]

Yes this should be possible! I can't replicate your setup but tested this by copying the DOS80 system tracks from a 800k disc to a 3" floppy which then booted fine.

Use BACK80 to copy a DOS80 system disc from your Gotek to a floppy.
Configure your drives by running CONFIG from the floppy. DRIVE 0 Gotek will be option D (DS-80) and Drive 1 option A (SS-40).
Select the HFE blank from GitHub on your Gotek and run BACK80 from the floppy to format the Gotek disc.
Lastly, use DOSCOPY to copy the DOS system tracks from the floppy to the Gotek.
Then you should be able to boot to 800k from the Gotek.

Selecting a different DSK and rebooting the Einstein should (in theory) boot to a different DOS! I can't test this so take care as I don't want to be responsible for you losing all your files

The system tracks on my blank formatted disc wouldn't work on your system - the configuration is different as my drives are the other way around! Given four drives (0-3) and four formats (SS-40, SS-80, DS-40, DS-80) that's a lot of different configurations

Richard

[Lardo Boffin]

Not doing very well here!

I ended up removing my 80 column card as it was randomly writing characters all over the screen. Kind of hard to follow instructions...

I copied System80 to a floppy in drive 1. I ran CONFIG and set 0 to D etc. and then when it says write DOS to... I select drive 1. It whirs away, and says OK.

If I then run BACK80 it tells me that drive 0 is still single sided 40 track. I have tried this with two different floppy discs now.

I tried formatting 0 on the gotek just in case but it was just 40 track.

Thanks for the detailed instructions though!

Doh!

[Lardo Boffin]

I will give the same a go when I get chance to get my other tatty down from the loft.

I wondering if it just doesn’t like - wasn’t programmed to expect drive 0 being 800k? I.e. the option was put there but never tested?

[retrogamer]

I can see the issue. Easily fixed ...

Essentially, DOS is loaded by the system from Drive 0, so the new DOS also needs to be saved to Drive 0 (to a blank DSK in the Gotek) so it gets booted. But you're right to save the configuration to Drive 1 so you can copy it to the Gotek later.

The easiest way is achieve this is to run CONFIG twice with exactly the same parameters, once for each drive.

You should then see 80 tracks for Drive 0 (although you and I know that the DSK image really has only 40 tracks!!). Reboot from this drive if 80 tracks doesn't show up in BACK80, but don't DIR or do anything else with this disc image as your system tracks and formatting are not aligned on this DSK.

I expect the computer will hang once you've formatted the HFE image as the computer will probably try to boot from this disc and it doesn't yet have a system track! Yikes!

If this happens change back to the DSK image on the Gotek, reset the computer and reboot the system so that you can then use DOSCOPY to copy the system tracks from Drive 1 to the HFE image in the Gotek. You should then have a bootable 800k disc in Drive 0. Booting from the Gotek should save considerable wear and tear on your actual drive!

Trying to reformat your DOS booting drive was never going to be an easy option!! Fingers crossed

Richard

[Lardo Boffin]

Thanks! I now have a bootable 800K image for drive 0.

D32BFD5B-6D08-4CDA-B841-961EA50B8C49.jpeg (3.98 MiB) Viewed 16596 times

It didn’t crash after formatting the HFE image so went very smoothly thanks.

[Lardo Boffin]

Here is a blank 800K image.

It assumes that drive 0 is 80T double sided (800K) and all other drives are 40T single sided.