WTB: Emulex MT-02 controller

Chuck Guzis cclist at sydex.com
Thu Apr 24 16:54:54 CDT 2008


Date: Thu, 24 Apr 2008 15:47:39 -0500
From: Jules Richardson

> Hmm, maybe the designers were sensible, and any critical timings are
> solely on the device response side - i.e. the host can take as long as it
> wants to process things, but the device must respond within a certain time
> period (and then just happily sits there until the host acknowledges).

QIC-02 is buffered via drive-local RAM, so it's not really fussy on 
the host-side timing.  These tapes are streamers, however, so you 
want to keep the tape moving; otherwise, it's back-up-a-piece-and-
take-a-running-start-at-reading-the-next-block.  Really slow--and 
hard on the tape.

> Of course none of this probably helps Chuck, who quite possibly doesn't
> want to be messing with designing hardware and writing driver software :-)
> It's just nice to speculate that it could be done once QIC interface
> boards are unobtainable...

Oh, Chuck has both QIC-36 and QIC-02 ISA inteface boards.  He just 
wants the convenience of not dealing with buggy NetBSD drivers (the 
Linux QIC-02 drivers don't work at all anymore) and not having to 
look for spare DMA and IRQs for the boards.  A QIC-02 host interface 
board is scarcely more complicated than an IDE interface.  OTOH, a 
QIC-36 interface is usually a full-length board, packed with a data 
separator, CPU, RAM and other logic.  From the CPU side, both appear 
as pretty much the same thing.

Cheers,
Chuck




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