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1356[Altair Computer Club] Re: Disk Drive

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  • ueoguy
    Dec 21 3:45 PM
      All,

      Here's some additional information I found on the site.....
      http://www.retrotechnology.com/herbs_stuff/d_altair.html

      The references to 'Tom' is Tom Sanderson...

      "There are versions of drives with a 50-pin interface and others with a
      Pertec interface. To identify drives by model and revision, Tom
      offered me the following "key to understanding the Pertec drive
      numbering system".

      "The first digit identifies drive motor type. A FD4xx number indicates
      a DC motor and a 5xx number indicates an AC Motor.

      The second digit identifies density. A FDx0x drive is single density
      and a FDx1x drive is single or double density. MITS used both FD410
      and FD510 drives, even though the MITS controller was only single density.

      The third digit is interface type. A FDxx0 is the "Basic" PRE-STANDARD
      Pertec interface an it is not 50 pins. A FDxx1 indicates a Basic
      interface with "Internal Daisy Chain". A FDxx4 number indicates a
      standard Shugart Interface. These drives were not used by MITS. Pertec
      used them in the PCC2000. They may be in the iCOM 3812,I'm not sure.

      An extension to the FDxxx number specifies Model Revision, for example
      FD514-06."

      Tom describes what he knows about the production history of use of
      these drives. "The original Altair drive was an FD400. Later
      production used a FD-510. I've also seen a FD-511 drive used with a
      FD-510 FD board. There are six versions of the FD-514. Changing
      versions required few component changes in addition to jumper changes.
      The FD514-06 revision provides a standard Shugart configuration.
      Another revision supported hard sector operation."

      So maybe Shugart and Pertec aren't as interchangeable as we first thought?

      I'm not sure if this clears anything up, or just muddies the water?

      Just Bob!....I have a headache!


      --- In altaircomputerclub@yahoogroups.com, "ueoguy" <ueoguy@...> wrote:
      >
      > Grant, et al
      >
      > I'm a bit late in responding to your post, but I have a bit of info
      > that might be of use. With regards to Pertec drives, the FD400 series
      > was the DC direct drive motor version used in the single disk DCDD
      > configuration, which was prone to a lot of heat related problems,
      > bridge rectifiers on the PS board melting the traces off the board,
      > and a stalled servo drive motor tended to fry the Tip 110/120
      > transistors on the drive itself, and overheating the motor windings.
      >
      > The FD500 series was more like the Shugart drives, with a belt drive,
      > and AC drive motor. They are most commonly found in the Dual disk
      > enclosure, and supplied with systems like the MITS 300 Business
      > System. That enclosure had an improved buffer board design, and even
      > the System controller boards used IDC cable and connectors, a much
      > cleaner design inside the Altair.
      >
      > I would really like to see a Shugart drive running on an Altair, but I
      > believe the only version that might work, is the SA-800-1"R". The "R"
      > suffix drives are the only ones that support "Hard Sectoring". The
      > SA-800-1 is soft sectored only, and has no jumpers for selecting the
      > number of sectors, 8, 16, 32.
      >
      > Another side comment, the Siemens 8" drives are supposed to be a
      > Shugart clone, so they may work as well!
      >
      > Just Bob!
      >
      >
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