Epson drives

Jim Scheef scheefj at
Tue Dec 28 20:26:10 CST 2010

HP did everything it could to shoot itself in the foot. After promising 
compatibility among the 100-Series machines, the floppy format produced 
by the 9114 driven by the HP110 Portable or the Portable Plus was 
different from the format produced by the HP150. There were clever 
format programs and device driver tricks to get around some of these 
incompatibilities as well as to allow the PPlus to make and use 3.5" 
floppies that could also be read and written by regular DOS machines. 
Sometimes I find it amazing that HP has survived!


On 12/28/2010 1:47 PM, Tony Duell wrote:
>> On 27 Dec 2010 at 14:45, Fred Cisin wrote:
>>> I saw multiple DIFFERENT upper limits (66 and 70) on discs (HP refused
>>> to call them "disks") that were supposedly the same format.
>> Indeed, the HP150 Series II floppies used 77 cylinders for data.
> Not really, this ia a drive unit and not system parameter.
> An HP150-II will use the 9121 signle-sided drive, where it formats it to
> 70 cylinders (and probably gives you 66 of them). I think an HP150 can
> use the later double-sided drives like the 9122 (and will format them to
> 77 cylinders), but it may need a BIOS ROM upgrade amd/or a later version
> of MS-DOS.
> -tony

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