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Roland Huisman
June 24th, 2017, 01:44 AM
Hi everyone,

Hard sectored disks are known to be difficult to write or make images off with a pc...

Paul Birkel mentioned (http://www.vcfed.org/forum/showthread.php?57716-S100-hard-disk-controller&p=460513#post460513) the Virtual Sector Generator (http://deramp.com/vsg.htm) to use
soft sectored disks in a hard sectored system.

I was wondering, if you make a simple device like this in de opposite way...
You read a hard sectored disk and the circuit counts the holes and put out just one pulse
to the PC like a soft sectored disk. Would it be possible to make and write images with a PC?
Or are you still missing a piece of data for the FDD controller which recognises a soft sector?

Regards, Roland

SomeGuy
June 24th, 2017, 02:41 AM
That would not work for transferring data to a hard sectored computer as the sectors would then not line up with the index holes.

I'm not aware that there is any current solution for this problem. Even the Kryoflux does not currently support hard sectored disks, every time that topic comes up on the KF forums, they complain that they don't have disks and hardware to test and develop with.

Chuck(G)
June 24th, 2017, 08:42 AM
A catweasel can handle this--it's not that difficult if you're not averse to writing some software. However, every hard-sectored floppy I've dealt with over the years has its own non-standard header format, a plain old PC floppy controller won't read them.

Actually, a semi-modern MCU could do this quite easily. All it takes is code.

glitch
June 24th, 2017, 09:24 AM
For North Star disks, you can use Dave Dunfield's NST (North Star Transfer). Everyone else is using it so any images you make will be useful to the rest of the community, too. I need to do a writeup on bootstrapping NST for non-North Star systems.

deramp5113
June 24th, 2017, 02:40 PM
I've written utilities to image numerous different hard sector formats to a PC (and vice-versa) using original hardware and a serial link to a PC. I can help with Altair 8" and 5.25" drives, the North Star single density and double density controllers, the Micropolis/Vector Graphic controller, and the Vector Graphic Tandon controller. I have a Heathkit and Polymorphic 8813 with their respective hard sector controllers I plan on restoring soon.

Let me know if you're working with any of these controllers.

Mike

Dwight Elvey
June 24th, 2017, 05:19 PM
I've written utilities to image numerous different hard sector formats to a PC (and vice-versa) using original hardware and a serial link to a PC. I can help with Altair 8" and 5.25" drives, the North Star single density and double density controllers, the Micropolis/Vector Graphic controller, and the Vector Graphic Tandon controller. I have a Heathkit and Polymorphic 8813 with their respective hard sector controllers I plan on restoring soon.

Let me know if you're working with any of these controllers.

Mike


Serial methods for both the H89/H8 and the Polymorphic 8813 already exist.
I wrote the base code for the H89 years ago. It has been upgraded and has a
nice windows interface now.
You load a simple boot loader that bootstraps the transfer program.
( takes about 50 bytes ).
It is available from SEBHC. You do need a working disk system on the
H89 or H8 and a serial board.
As for the Polymorphic 8813. There is already a transfer program
called ftp ( not the ftp most people know today ). It comes on most
system disk for the Polymorphic 8813. I've hacked its hand shake a number
of years ago and if you'd like I can dig it up. You do need a booting a
system disk on the Polymorphic 8813 though.
It was relatively simple as I recall. It is a file based transfer unlike the
H89 that is a true disk image transfer that doesn't require any
bootable disk on the H89. It just needs a hard sectored disk.
If you have a soft sectored controller on the H89 you can use utilities
like Dave's.
Dwight

deramp5113
June 25th, 2017, 05:35 AM
Dwight, do you happen to have a manual for the Poly hard sectored controller?

Mike

Dwight Elvey
June 25th, 2017, 06:23 AM
I don't think I have a manual for the hard sectored controller.
It is no all that complicated though. It is similar to others, it has a
synchronous serial port and a simple clock/data separator.
Any problems you might be having are more likely the disk drive.
I'd not fiddle with the Polymorphic 8813 much at the hardware level.
It had RAM issues when I got it and a blown power supply capacitor.
Someplace I have the schematic for their soft sectored controller.
It has a Z80 on it that I always thought was funny because it is
more powerful than the main CPU. It interfaces to the system, completely
different.
Back to the hard sectored. It is said that it is similar to the north star
controller but that there is something that makes them not fully
compatible.
Dwight

Roland Huisman
June 25th, 2017, 01:03 PM
For North Star disks, you can use Dave Dunfield's NST (North Star Transfer). Everyone else is using it so any images you make will be useful to the rest of the community, too. I need to do a writeup on bootstrapping NST for non-North Star systems.

Oh That is nice! I'm currently busy with my Northstar. Does that run under northstar dos or cp/m?
But I'm not sure I have Northstar DOS disks...

Thanks!
Roland

glitch
June 25th, 2017, 01:16 PM
It runs under North Star DOS, but you can use it to create a disk from scratch, so no worries if you don't have any North Star DOS disks!

mgarlanger
August 3rd, 2017, 07:35 PM
I wrote software for the Device Side FC5025, which will image heathkit hard-sectored disks. The code is up on github - https://github.com/mgarlanger/heath-imager

Dwight Elvey
August 3rd, 2017, 08:51 PM
Hi Mark
Is the chip a uP or a controller chip? Is it a sampling chip or
is it a typical floppy controller chip?
Dwight

tingo
August 4th, 2017, 02:24 PM
It is read-only: http://www.deviceside.com/fc5025.html

mgarlanger
August 5th, 2017, 09:01 PM
I think it's just sampling, it connects via USB, unique programming, nothing like a regular floppy controller. And as tingo mentioned, it is read-only.

Chuck(G)
August 6th, 2017, 08:36 AM
Just about any modern ARM MCU can do the job of reading--and writing can be accomplished by using the PWM facities of the ARM to essentially do the reverse.