Re: ZIP Chip Heartbreak

[express@pro-nsdapple.cts.com (Jeff Goodman)]

I have almost exactly the same setup, and have had the ZIP8 for several
years now.  A few months ago I decided I wanted a new SCSI controller, I
had a Rev C card but it was starting to crash the machine from time to
time.  (Might have started happening when I spilled coffee all over the
computer, I'm not sure?)  Anyway, I was going to get a larger hard drive as
well, I was getting tired of trying to put all the Apple programs I like
and a large enough PCTransporter hard drive volume on a old slow 20 meg
hard drive.  Well, one of the first things I very quickly found out, is the
DMA thing the HS SCSI card does (I got a clue from reading the Tech Notes)
anyway, I learned that DMA transfers are very timing dependent.  The big
clue is just as in your case, by pressing escape you turn off the Zip Chip
all together, and then DMA transfers can take place like the HS SCSI card
wants.  I still liked the idea of having a new card, and the 8mhz zip makes
up for the loss of the DMA SCSI card.  The manual will tell you how to turn
DMA off, then run the zip with all slots as fast as it will go, it works
great that way for me.

Hope that helps
l
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Jeff Goodman
ProLine: express@pro-nsdapple.cts.com