Turbodos on a Horizon 8/16 system

Dave Dunfield dave06a at dunfield.com
Wed Feb 21 07:51:14 CST 2007

> Continuing my story of trying to recover the contents of the hard drive 
> in my Horizon 8/16 system, I took Dave Dunfield's advice and wrote a 
> small program to read each sector from the hard drive and dump it.  30 
> MB of disk data at 9600 baud, printed as ASCII hex.  It took a while.
> The mystery remains -- what is it?
> There is no plain-text to be found anywhere ... not even accidental 
> sequences.  I thought that perhaps it is a lot of binary data.  Some of 
> it must be code.  Searching the hex for "CD0500" (which is "CALL 0005", 
> the CP/M call vector) has no hits.

I agree with Chuck ... this is probably as test pattern.

I converted your HEX section to binary, and ran it through about a dozen
disassemblers for various CPUs of the era, and found nothing that looked
like code.

Tried complimenting, reversing bit positions, and still nothing that looks
like code - tried droppng the high bit on all of these and didn't see any
recognizable text either.

Perhaps the former owned did a read/write hard drive test before
dcomissioning he system to remove his data from it? (or did a read/write
test when installing it, and never did get around to using it).


PS: Thanks for the N* TurboDos images, I've just put them up on the site,
    along with several other N* images that I have had pending.

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

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