Re: annc: GS/OS AppleDisk5.25 Project

["Charlie" <charlieDOTd@verEYEzon.net>]

"Steven Hirsch" <snhirsch@gmail.com> wrote in message 
2OadnZ7TefVfQxfUnZ2dnUVZ_s7inZ2d@giganews.com">news:2OadnZ7TefVfQxfUnZ2dnUVZ_s7inZ2d@giganews.com...
> Charlie wrote:
>> "Steven Hirsch" <snhirsch@gmail.com> wrote in message 
>> fu2dnU05iqHEthfUnZ2dnUVZ_vSdnZ2d@giganews.com">news:fu2dnU05iqHEthfUnZ2dnUVZ_vSdnZ2d@giganews.com...
>>> Charlie wrote:
>>>
>>>> I'm not familiar with the Copy II Plus board but another interesting 
>>>> card is the PC Transporter.  It can read/write an Apple II 3.5" drive 
>>>> in either GCR with the variable speed (800K) or PC MFM with single 
>>>> speed (720K).  In this case though, I don't believe the speed is done 
>>>> in software.  If I remember correctly the PC Transporter somehow keeps 
>>>> the speed from varying in the drive.
>>>
>>> The PCT uses a real Apple drive to do 800K 3.5" diskettes AFAIK.
>>
>> Yes, you are correct.  I shouldn't have brought up the PC Transporter.  I 
>> was just referring to it as a curiosity because I believe it manages to 
>> do multi-speed and single speed (hardware rotational speed not software 
>> read/write speed) on an Apple drive.
>
> I'm sceptical that the PCT is doing anything special at all.  I'm of the 
> impression that the variable speed magic is simply built into the drive 
> itself

Well I won't argue the point since I don't have the PCT running at the 
moment.  Maybe someone else with a PCT can confirm/shoot me down.

> Unless I'm confusing this with the Unidisk 3.5 (original) the drive 
> presents itself as a sequence of blocks and completely hides the fact that 
> tracks and sectors are involved.

I believe you are referring to the Unidisk 3.5 drive which has it's own 
processor built in (a so-called smart drive).  An Apple 3.5" drive has none 
of that fancy stuff.

Charlie