Date   : Thu, 10 Oct 1985 09:49:00-PDT
From   : STANLEY@USC-ECLB.ARPA
Subject: Re: A way to read 48 tpi disks on 96 tpi drives?

       
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    Date: 5 Oct 85 16:37:40 GMT
    From: ir320 <ir320%sdcc6.uucp@BRL.ARPA>
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    Subject: A way to read 48 tpi disks on 96 tpi drives?
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    Hello netlanders,
    
    I am getting a new computer and need to decide whether to get 96 tpi drives
    or 48 tpi drives.  I know I get double the storage with 96 tpi, but I also
    give up disk compatability with them don't I?  Is there a way I could
    read/write a 48 tpi disks on a 96 tpi machine.  (The system is question
    is the new SB180 system described in Byte.)  Can other systems write disks
    for these drives?
    
    John Antypas
    UC San Diego
    
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             --------------------
               
John,

You can read 48 tpi disks on 96 tpi drives by double-stepping the
head for each track; Heath H89's have been doing this for a long
time.  Writing in 48 tpi from a 96 tpi drive is another thing.
I've been told it can be done, and have seen it happen
occasionally on an IBM PC/AT, but my experience tells me it is a
very dicey business.  Reading can be done dependably, but not
writing.

                                ...Dick Stanley