Alternative Hardware Design for Floppy Interface

Andrew Lynch lynchaj at
Sat Oct 20 12:33:21 CDT 2007

At 01:42 PM 10/19/2007, you wrote:
>Grant Stockly wrote:
>>What do you guys think?  The thing has a peripheral expansion header.
>>We could hook a modern floppy chip to that, connectors for 
>>different drives, and off we go...
>What's the cost like? Is the board made up of separate components 
>(CPU, ROM, RAM, USB chip, buffers for I/O, Ethernet chip etc.)?
>I'd find Ethernet more useful than USB, and in an ideal world I'd 
>prefer a board where the functional areas are segregated (rather 
>than some complex and expensive single chip, where if disaster 
>strikes the thing basically needs throwing out and replacing as a 
>complete unit)

The base eZ80SBC from howard is $250.  Add $100 for the disk board...



By the time you add in all the costs of the CPU board with IO, case, power
supply, cables, documentation, plus the specialized disk controller, AND
write most if not all of the software this project is quickly going to
become uneconomical for all but the most patient and financially well off.

You could use a throw away old 486 or Pentium II computer with ISA and/or
PCI slots to provide any interface you'd like (ethernet, SCSI, ST506, USB,
whatever) for a whole lot less time and effort.  A double sided 48tpi floppy
drive will read practically any format given the right controller.  The same
can be done for whatever sort of drive you'd like to test.

I have made and am using a few bench stations for testing floppy drives,
ST506/ST412 hard drives, SCSI, etc for a small fraction of what the cost you
are proposing.  I am sure many others here are doing the same thing as well.

In addition, reusing old PCs effectively removes them from the waste stream
which is not only economical it is environmentally friendly as well.  Get a
small enough PC and they are portable assuming you choose standard interface
for peripherals like VGA, PS/2 keyboards & mice, etc.

On top of the above, as an added bonus much of the software is already
written.  You can use ImageDisk for soft sector floppy disks, SpinRite II
for ST506/ST412 hard disks, etc.

Respectfully, it seems like the proposals being discussed are reinventing
the wheel by developing and/or repurposing a new CPU and IO board rather
than reusing proven and cost effective solutions which already exist.

It is just my $0.02.  Best of luck with your project.  Thanks!

Andrew Lynch

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