Reading various format 5.25" floppies on

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Mon Jun 16 17:03:19 2003

> Always start by being clear about whether you want to
> duplicate a diskette of the other ("alien") format
> read/write an image of the alien diskette

In general, if a PC (say) is capable of duplicating a disk, then it's
also capablie of recoridng and rewriting a disk image (this just involves
saving the data that would have been transfered from the source to
destination disks in a normal PC file of some suitable format). So this
is a simple-ish matter of programming

> read/write files from the alien diskette

This, again, can be done in software if the disk is physically readable,
but it involves and understanding of the filesystem involved...

> Use files from one program in another program

Again software, but geting documentation on application files can be
'interesting'...

> ON A PC, using the PC hardware, a PC CAN NOT READ ANYTHING other than
> "Western Digital" style MFM sectors on a PC, using PC hardware,

Even then you might have problems. There is an index timing problem that
means the Intel disk controllers can't read some disks formatted by real
Western Digital chips (if the first sector header starts too soon after
the index pulse, the Intel controller won't see it). Some clone disk
controllers mighy have got this right, some certainly haven't!

> The CONTENT of the file is another problem. Text files are no
> problem. But, many versions of BASIC "tokenize" the program for storage
> (replace every "keyword" with an abbreviation), and the tokens are not
> even the same from one version to another. But, as you said, you can

They're not even the same on related machines. The UK Dragon and the
TRS-80 CoCo are much the same machine (essentially the same hardware,
microsoft BASIC in ROM), but the tokens are assigned in a different
order. You can load a BASIC progeam saved in ASCII on either machine,
but not one stored in the (default) tokenised format.

> There have been some programs for transferring files from various MFM
> diskettes to and from PC, including:
> 22DISK
> Flagstaff (No longer available)
> Hypercross (TRS-80 only) (No longer available)
> Media Master (No longer available)
> Oswego Systems (HP only) (No longer available)
> Uniform (No longer available)
> XenoCopy-PC (Available only by personally contacting the author)
>
> Each handles a fixed finite group of formats. Most have provision for
> adding in additional formats yourself, but almost nobody ever succeeds in
> doing so, and after fielding too many "which numbers do I put in to make

I have mananged to add a new CP/M format (FTS-88 double density 8") to
22disk, I think.

Is it _possible_ to add formats to Hypercross? I have the original disks
and manaals for the Model 4 version, and it doesn't say it is. If it is,
what's the trick?

-tony
Received on Mon Jun 16 2003 - 17:03:19 BST