[rescue] Sick Dreamcast hacker

[Dave McGuire]

On June 18, Joshua D Boyd wrote:
> I'm at a loss for what to do for sound cards though.  I'm increasingly
> unhappy with the SBLive!s linux support, but it appears that my only
> choises are to move back to ISA cards (I have a turtle beach card that
> is very well supported except for that ISAPNP thing) or move up to a
> RME DIGI card (rarely show up on ebay, usually expensive, requires a
> seperate $100 driver, and requires seperate AD/DA units).

  Argh. :-(

> At the moment it isn't too much of an issue, but I want to sooner or
> later set up an area for recording etc, and while Opcode on a Mac is
> great for recording, there are an increasing number of cool linux
> tools (effects that are almost fast enough for inline usage,
> accompanyment software, virtual synths, etc).  But, maybe things will
> change by the time I have the spare time to do something like this.

  I don't understand why there seems to be such a hole in the audio
I/O market.  It seems like it just hasn't advanced along with
everything else, except for the really expensive cards.

> I wouldn't argue there.  But then again, I can't really imagine ever
> making my own sbus or PCI card, so perhaps sometimes primitive is
> good. 

  Agreed 100%.

> >   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.
> 
> I'll assume that what you said is really hard since I don't know what
> duty cycles for square waves are.  Do you mean reduce the frequency
> 12-15% or what?

  Well right now it's a plain old 50% duty cycle square wave, and I need
to reduce the "on" time from 50% to (not by) 12-15%.  I'm using a
74HC123 retriggerable one-shot now (running about 28%) but I seem to
be at the chip's pulse width limit. :-(

         -Dave

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