Hard sector format

[Jeff]

HxC appears to be interpreting the geometry although the data itself is unsurprisingly not correct.

According to your picture you have not imported the raw file correctly.

To read your kryoflux dump, drag and drop one of the kf .raw files on the main window. The importation processing time can be long, be patient...

[exidyboy]

To read your kryoflux dump, drag and drop one of the kf .raw files on the main window. The importation processing time can be long, be patient...

Yes you are quite right
Nothing but a sea of red now.
Thanks for taking a look though Jeff.

[Jeff]

Nothing but a sea of red now.

Not exactly : I see the odd or even tracks without red. This probably means that the disk have large tracks. place an empty file named "doublestep" in the raw files folder and reload the raw. The software will skip the inter-tracks "tracks".

Once done don't hesitate to enable more decoders : FM,MFM, HEATHKIT, Northstar...
It is possible that the software can't decode these tracks if this machine use an "alien" sector encoding, but at least you see if the disk dump appears "clean" in the track viewer.

Also please some post track view mode screens (one odd & one even track). These are quite usefull to figure out what is going on.

[exidyboy]

Not exactly : I see the odd or even tracks without red. This probably means that the disk have large tracks. place an empty file named "doublestep" in the raw files folder and reload the raw. The software will skip the inter-tracks "tracks".

If by large tracks you mean written by a 40 track drive then yes this is my assumption.
WIth the doublestep file (no extension) the results look very good.

Once done don't hesitate to enable more decoders : FM,MFM, HEATHKIT, Northstar...

I tried all those but the results don't look any different.

It is possible that the software can't decode these tracks if this machine use an "alien" sector encoding, but at least you see if the disk dump appears "clean" in the track viewer.

The controller is pure TTL so probably will not correspond with any of the profiles you have currently implemented but hopefully is close.

Also please some post track view mode screens (one odd & one even track). These are quite usefull to figure out what is going on.

Presumably you want the odd and evens before the double-stepping is applied?

[Jeff]

The dump appears good to me. The red lines are the sector write splices.

Please :

- Show me a track in track viewer mode.
- Enable all decoders available (you can enable all in the same time).

[exidyboy]

Selected tracks from 3 different discs:

Disk 33 Track 0 Side 0


Disk 33 Track 0 Side 1


Disk 37 Track 20 Side 0


Disk 37 Track 20 Side 1


Disk 49 Track 34 Side 0


Disk 49 Track 34 Side 1

[exidyboy]

Once done don't hesitate to enable more decoders : FM,MFM, HEATHKIT, Northstar...

Here is an interesting snippet from a 1985 Sorcerer newsletter.

[Jeff]

Yes interesting. So the format is supposed to be close enough to the northstar format. is there some technicals informations about the sector format somewhere ?

[exidyboy]

I have not been able to find any documentation yet although Dutchacorn (from earlier in this thread) had some timing diagram screen shots - but you guys were saying the timing couldn't have been correct for 10 sector ...

I take the excerpt from the newsletter article to mean that a CP/M system with a Northstar controller could read a Vista format disc if appropriate changed were made in the CP/M software.

Edit:
I believe the discs would have been written with an MPI B51 40 track drive single-sided drive.
205K formatted.
I realise that doesn't help you with the sector though.

[exidyboy]

Progress has been made on the sector format and preamble.
Focus is now on the checksum algorithm.

[exidyboy]

All the Vista hard sector discs for the Exidy Sorcerer have now been imaged and individual files extracted.

Thanks to Kryoflux for their work to add support for the hard sector format to their technology stack and for input into the format.

Thanks to Simon Owen for investigating a lot of time reverse engineering the Vista format and processing the Kryoflux preservation streams into raw images. The next release of Samdisk will support this Vista hard sector format.

Various contributors on VCFED has taken Simon's .raw files and extracted files using cpmtools/libdisk.

Technical documentation for the Vista system is still MIA but page 114 of the Sorcerer's Apprentice newsletter Vol 4 No. 6 (September 1982) contains some engineering details attesting to the rumoured proximity of the Northstar and Vista formats.
I'm sure those details would have helped Simon if they had come to light at the time.

The details might also assist in evaluating the feasibility of supporting hard sector disks in HxC on either current or future hardware.
See page 114-116 of http://www.bitsavers.org/pdf/exidy/Sorc ... ep1982.pdf
and source code of the conversion utility from page 126.

Thanks of course to Jeff and the contributors on this forum.

A great international team effort.

[rstek37]

I haven't been on for over a year due to a lot of things (and not even related to covid).

But I am still interested in NorthStar support. I have a Horizon and a ton of floppies which I would like to both archive and actually use primarily on my PC. I would secondarily love the ability to take files from my PC and write them on a 5.25" floppy on my P-III machine so that they could be read on the Horizon, or to use my PC to make copies of N* disks. Unfortunately for me most of the technical talk about how this can be done, I can only follow somewhat. I can offer to provide diskettes, SS and DS, in both N* DOS format and several variations of CP/M format (i.e., Lifeboat CP/M for N*, N* CP/M) DD and maybe QD. The N* controller and drives were very popular with IMSAI owners and there is still interest. E.g., Mike Douglas (deramp.com) developed the Virtual Sector Generator to allow the use of soft-sectored disks with N* controllers; Horizons show up regularly on ebay usually for $500-$900.

If there is any way I could be useful and help I will, but I am technically-challenged!

[Jeff]

FYI i have released "Pauline", a floppy drive simulator and high resolution floppy dumper based on an FPGA board (the de10-nano).

For sure this solution will work "out the box" with any Hard sectored machines. This solution doesn't have the memory size and write latency issues that all the low cost flash based floppy emulators have :

Demonstration (dump feature) :
https://www.youtube.com/watch?v=PZiyms6lo4U

All is open source :
https://sourceforge.net/p/hxcfloppyemu/ ... ine/trunk/

[rstek37]

Thank you for the info, Jeff. Unfortunately I don't know anyone who even uses Linux or could build a board given the files on sourceforge. If you know of someone (yourself?) who is doing a small run of these, I would purchase one and get a popular Linux release to install on a spare machine.

[Jeff]

Thank you for the info, Jeff. Unfortunately I don't know anyone who even uses Linux or could build a board given the files on sourceforge. If you know of someone (yourself?) who is doing a small run of these, I would purchase one and get a popular Linux release to install on a spare machine.

You don't need to have linux, you just need to write this image to the de10-nano SD card :

https://hxc2001.com/pauline/

You can control the board through a web page so no need to be an unix expert to use it

There is some batch was done :
(the one from the Musee Bolo :
https://twitter.com/danthedrac/status/1 ... 8901935105
)

i hope that Lotharek will start its production soon.