[sebhc] Re-creating actual floppies from archive

Dave Dunfield dave06a at dunfield.com
Wed Mar 15 05:45:20 CST 2006

> Hi Joe
>  .h8d are a hard sectored images. Use my utility
> in the utilities directory. You need to actually
> write the disk on a H89 with a hard sectored controller.
> You'll need a PC that boots to real DOS, serial cable
> and the H89 must have a serial board with the LP: port.
> You also need a hard sectored disk.
>  I just described this to someone else a few messages back.
> Using H89LDR9.ZIP.
>  Dave's site has some tools to handle emulation on the
> a PC and I think he has a way to transform h8d files
> to his format used by his emulator.
>  I doubt that PIE for hard sector HDOS would run under CP/M.
> Dwight

Ok - now I understand whats going on - the original message was
posted in response to directions on how to find ImageDisk on my
site, which caused me to think it was related to ImageDisk (or at
least something from my site).

Unless someone has abused the extension for other purposes,
.H8D is just a raw image of the binary content of the hard-sectored
disks. It does not contain the headers, and the data is in 1:1 (ie:
non interleaved) ordering.

I "invented" the .H8D extension name (not the file format) when I
created my H8 simulator - it goes along with .H8T which is a H8
Tape Image File. The format of the .H8D file is described in the
help for the simulator.

Since I don't have a disk controller in my real H8, I have never
actually read or written a physical disk to or from these images.
I obtained my H8DOS boot disks from the SEBHC archive, and
they were already in the format described - but originally named
with a different extension. Since then, I believe some others have
adopted the .H8D extension for this type of file.

All you should have to do is to format a disk and transfer over
each sector from a PC serially - and write them in order to the
disk, starting with the first sector on track-0 and continuing to
the end of the disk/image.

I have done a similar transfer program for NorthStar hard-
sectored disks, and it works exactly that way.

You can mount, boot and access .H8D disk images in my PC
based H8 simulator (available from my site, and also on SEBHC).

If I ever get a physical H17, I would write a little program that could
be booted as a tape image to read/write the disk images - Perhaps
Dwights program does this?

For soft-sectored disks, you should be able to use my ImageDisk
program. If you have a raw-binary image, you can use the supplied
BIN2IMD utility to add format information (which you will have to
know and specify), and then the main IMD program to write the
image to a physical floppy disk.


dave06a (at)    Dave Dunfield
dunfield (dot)  Firmware development services & tools: www.dunfield.com
com             Collector of vintage computing equipment:

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