[rescue] Sick Dreamcast hacker

[Dave McGuire]

On June 18, Joshua D Boyd wrote:
> >   ISA sucks sweaty donkey balls.  Think "edge-triggered interrupts".
> > It's also painfully slow.
> 
> I couldn't tell what the problems with those are.

  It means you can't share interrupts between peripherals.

> Yes, it is painfully slow.  But it still can be used for worthwhile
> things.  It is fast enough to stream flac files, or to play well
> compressed video.  Let alone being fast enough to read and store
> email, or whatever else.

  Yes, you make an excellent point as always.  It has been, however,
badly abused and misapplied to tasks it was never designed to do, and
isn't particularly good at...like LOTS of other PeeCee hardware.

> I was fine with ISA (speed aside) until people started trying to make
> it PnP.

  Agreed.  I can't tell you the number of time I've lost sleep over
3C509 cards.  Blargh.

> And the docs I have make it look easy enough to build cards for.

  That doesn't make it a well-designed bus. ;)

  The ISA bus was never designed to be a generic end-all be-all bus.
It's basically a physical extension of the 8088's bus with some
interrupt and DMA stuff tacked on, and not much else.  For what it is,
it's perfectly reasonable.  But compared to much more modern buses
like Sbus and PCI it's rather primitive.

  But yes, it's very easy to build stuff for.  In that it still has
tremendous value, in my opinion.

  So here I am trying to come up with a circuit to reduce the duty cycle
of a 460KHz square wave down to about 12-15% using a small number of
inexpensive components.  I like hacking electronics, but this part is
*not* fun.

      -Dave

-- 
Dave McGuire                       "*BURRRP!*  Mmm...tastes like cannoli,
St. Petersburg, FL                    smells like garlic!" -Sridhar