DVK, UKNC (LSI-11 USSR) MY Disk

[kapitan-u]

Hi!

I'm wondering if HxC may consider implementation of DVK, UKNC MY disk support.
DVK and UKNC is a family of LSI-11 computers widely used in USSR.

MY format

MFM, 300 RPM, 250000 bps

Possible disk types:
5"25 40 tracks, 2 sides, Sector 512 bytes, 10 sectors per track, 409600 bytes formatted capacity
5"25 80 tracks, 2 sides, Sector 512 bytes, 10 sectors per track, 819200 bytes formatted capacity

format is almost compatible with ISO MFM, the only difference it has NO IAM index mark in the beginning of the track.
I have actual UKNC computer and bootable floppy. I have tried two methods:
- loading raw image (dsk file and profile is attached here)
- floppy disk dump
booth not working the same way. My assumption is that HxC is using standard ISO format in booth cases.
In order to get it working it will be enough just to drop IAM index mark. Please advise if it is possible.

Kind regards,
Oleksandr Kapitanenko

[kapitan-u]

PS: I can try host low level format on HxC, but I do not understand where to download:
"Some blank disk images with various density will be available for download on the HxC2001 website."
or how to create such blank images. Please advise.

[Jeff]

PS: I can try host low level format on HxC, but I do not understand where to download:
"Some blank disk images with various density will be available for download on the HxC2001 website."
or how to create such blank images. Please advise.

just create any raw blank image and format it with the machine. Nothing else is needed.

[kapitan-u]

My initial post contain errors, so once again:

MY format

MFM, 300 RPM, 250000 bps

Possible disk types:
5"25 40 tracks, 2 sides, Sector 512 bytes, 10 sectors per track, 409600 bytes formatted capacity
5"25 80 tracks, 2 sides, Sector 512 bytes, 10 sectors per track, 819200 bytes formatted capacity

format is compatible with ISO MFM (NOT compatible with IBM MFM) this is confirmed by source code research and
formatting actual floppy on PC using special software ukdsk+fdrawcmd in ISO mode - result floppy worked OK on target computer.
(3"5 FDD + HD floppy with closed HD window)

This type of formatting should work OK on HxC without any problems in two modes:
1. floppy disk dump
HxCFloppyEmulator on the same PC as ukdsk+fdrawcmd dumping disk OK, but resulting hfe does not work
I have created 14 рау files from dump with all possible interface modes - none is working
2. loading raw image
using config file attached here (not the original post, but here), resulting hfe does not work

It is worth to mention, that if I export 1 & 2 to XML - i receive two 100% identical files, which makes me confident about track/sector/side order in my raw dsk file

[kapitan-u]

I'm using SD HxCFloppyEmulator firmware upgrade v1.8.2.40
also tried host low level format with an empty image - do not work.

format works OK on actual floppy drive, on HxC it goes to read mode first and stop with an error

[Jeff]

I'm using SD HxCFloppyEmulator firmware upgrade v1.8.2.40
also tried host low level format with an empty image - do not work.

format works OK on actual floppy drive, on HxC it goes to read mode first and stop with an error

share the hfe file here.

[kapitan-u]

I'm attaching dump hfe here.
Other findings:
1. host controller is NOT using pin2 and is using pin 34, so I'm using now custom settings pin 34=low
2. I have very good documentation of host disk format in Russian and now I'm 100% confident, that standard ISO MFM should work.
3. Now I'm looking on electrical side. Controller has 200 ohm pull up resistors on input data lines, which is OK for Panasonic FDD, but too low for HxC.
Signals not going low enough for logical zero. After resistor replacement signals have good levels, Panasonic FDD is still OK, HxC still not working.

However, I have some progress: one of ten attempts system is able to read boot loader from first sector and I get «?BOOT-U-^I/O error» message on the screen.
It is definitely from disk, not from ROM!

Here is read data scope. Top one is Panasonic FDD and bottom one is HxC
horizontal scale 2 us

scope.jpg (22.26 KiB) Viewed 12485 times

[Jeff]

Please put here the HFE file formatted from this machine.
Also : Have you a schematic of this machine ?

[kapitan-u]

I'm unable to format. Machine tries to read first for some reason and newer goes to writing.
hfe from previous post is the dump of working floppy.
here is the schematics: http://retropc.org/biblioteka/0115.djvu
but it is very simple. There is just one IC and RD signal wired right to it.
IC К1801ВП1-097 is unique soviet development has no western equivalents.
I'm attaching detailed description of the controller and IC here. It is in Russian, but you can get the feeling how detailed it is.
I have read it, you can trust me, that the disk format is standard ISO MFM, which I also confirmed by creating real floppies.

[kapitan-u]

OK, pulse width hypothesis is dismissed.
I've tried to form short and wide pulses using monostable multivibrator SN74121.
Panasonic FDD is working in both cases and HxC is not in both cases.

[Jeff]

Your image use the Emu Shugart mode. Retry with the generic shugart.

[kapitan-u]

New dump in generic shugart mode - same result.

[kapitan-u]

Jeff,

May I mail you a working floppy for the experiments?

[Jeff]

Jeff,

May I mail you a working floppy for the experiments?

yes.

i sent to you my mail by email.

[Jeff]

Jeff,

May I mail you a working floppy for the experiments?

And what about the RPM ? the machine is using an 300RPM or 360RPM drive ?