[rescue] Various machines for sale

[Dave McGuire]

On 1/8/25 23:44, Maciej W. Rozycki wrote:
>>> I had some HP Apollo 735 or 785 systems years ago that had SCSI
>>> connected floppy drives.  --  It was the same bus as the hard drives.
>>
>>     Later HP-9000 systems too, like the internal floppy drive on the
>> -382.  And many DEC workstations.
> 
>   In reality the DEC implementation just used an 8080-based microcomputer
> with the usual peripherals in a 5.25" half-height drive form factor to
> interface a standard PC FDC to SCSI.  I have one of those.

   ...and many earlier SCSI hard drives used an 80186 microprocessor 
(with its usual peripherals built-in) implementing the SCSI protocol and 
talking to a C/H/S hard disk. :)  Just like that package implements a 
SCSI mass storage device, so does DEC's (HP's, etc) floppy drive assembly.

>>> Also, what was the interface technology for floppy drives in older SCSI
>>> based Mac computers?  Did they have an IDE interface just for the floppy
>>> or was the floppy SCSI?
>>
>>     Neither.  Using IDE to control a floppy would be a challenge, as the
>> whole "design" (using the word loosely!) of IDE is centered around the
>> specific register layouts of an early Western Digital hard disk
>> controller chipset.
> 
>   Which was done with ATAPI though, which in turn is just SCSI-over-IDE.

   ATAPI is not using IDE to control a floppy.  Using ATAPI (as you 
stated) moves the SCSI protocol over the stunted IDE interface.

            -Dave

-- 
Dave McGuire, AK4HZ
New Kensington, PA