FDDI, was: Re: [rescue] u2 drive trays

Michael Thompson m_thompson at ids.net
Wed Aug 20 16:17:56 CDT 2003

>> >>    Yeah that'd be neat...I just wish Qbus weren't so blasted SLOW.
>> >>
>> >>    Qbus was a introduced as a smaller, lower-cost alternative to 
>> >> Unibus,
>> >> which runs at TWICE the speed of Qbus.  (Qbus multiplexes the address
>> >> and data lines on the same backplane wires) If they really had to
>> >> discontinue one and keep the other, they should have kept Unibus!
>> >>
>> >>    So much for "newer" automatically being "better".
>> >
>> > XMI?
>> > VAXBI?
>>    But those *are* better.
>Yes, and they should have discontinued both UNIBUS and QBUS in favor of
>them both, but they were still doing QBUS until the end of the VAX
>development.  I would have loved to have a BA440-sized cabinet that used
>a 4000/700-speed CPU with a VAXBI or XMI bus instead of the QBUS.

There was a little issue with the $250,000 license fee to develop boards on
the VAXBI bus that killed its acceptance.

Michael Thompson
E-Mail: M_Thompson at IDS.net

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