Re: [sdiy] My New Project - PCSYNTH

[Scott Gravenhorst]

=?iso-8859-2?Q?Roman?= <modular at go2.pl> wrote:
>I can't see why the I/O instruction could be so slow.
>Have you tried to watch on the scope I/O CS line in the ISA slot?

No, but I do plan to test an Intel Pentium with the same program to see if this is common.  I'd
read that port operations are slow, but that is a bit slower than I expected.  My assembler book
lists "out" as a 13 cycle instruction, but 1.5 uS is FAR more than 13 uS at 133 MHz.  

>I'm assuming the Parallel controller may have some overhead.
>OTOH 586 is far more twisted than 8086 - the last one I know from the inside a bit.
>As for the sloppy edges - yes, it's because of EMI suppression. 
>They are usually 2nF caps to GND on the port outputs. 
>
>Have you considered making ISA card with DAC mapped to memory space instead of I/O space?

I think that would fix the problem of slow I/O, but I have no facility to make such a PCB.  I
always work point to point on pre-etched prototyping vectorboard.  That's how I will make the DAC part.




>Roman
>
>---- Wiadomo¶æ Oryginalna ----
>Od: Scott Gravenhorst <music.maker at gte.net>
>Do: synth-diy at dropmix.xs4all.nl
>Data: Sun, 05 Jun 2005 18:12:08 -0700
>Temat: Re: [sdiy] My New Project - PCSYNTH
>
>> I'm trying to do this with the lowest end hardware around. 
>> Literally junk, in my case, a Am-5x86/133 (which is really an
>> enhanced 486).  I'm also trying to do this without buying
>> *anything* because of my abject poverty.  I also want to stay
>> away from a Windows operating system.  I've been thinking
>> about doing this for some years, it is now time to try it. 
>> If it doesn't work, well then I'll try something else, but I
>> believe I can do this, even with slow I/O.
>> 
>> "tomg" <e4m at houston.rr.com> wrote:
>> >Hi Scott...  What if you could do it in software? 
>> >I'm talking about Synthedit. I used to run it on a 
>> >500Mhz with a SB Live.
>> >
>> >In case you think it might sound like crap. 
>> 
>> I would never assume that.  I just really don't like
>> programming in a Windows environment.  I've done it, I don't
>> like it.
>> 
>> Doing this the way I'm doing it makes it all mine.  The only
>> tools I will use are an assembler and a soldering iron to
>> build the DAC interface.
>> 
>> And thanks for this, I will keep this information handy as an
>> alternative in case this fails.
>> 
>> >Here's 
>> >a couple of tunes by Tim Conrardy performed on his 
>> >M42 (Synthedit) Vsti. That's not a SB live  :)
>> >http://www.algomusic.nl/products_M42.html
>> >
>> >http://www.algomusic.nl/mp3/Opuim.mp3
>> >
>> >http://www.algomusic.nl/mp3/M42%20Journey.mp3
>> >
>> >VSTi host - editor Free - $20.00
>> >http://www.synthedit.com/ 
>> >My free SC P-600 emulator. (synthedit)
>> >http://www.ele4music.com/vst/p-600.zip
>> >
>> >You'll need a VSTi  host or use Synthedit.
>> >Mini Host - Donation Ware...
>> >http://www.tobybear.de/p_minihost.html
>> >VSTHost - Donation Ware...
>> >http://www.hermannseib.com/english/vsthost.html
>> >
>> >After SE (synthedit) you can go C++, or 
>> >SynthMaker it's a  little of both... but not quite 
>> >ready..
>> >
>> >He didn't build these with SE but I really like 
>> >Antti's Augur & ASynth. - Donation Ware..
>> >http://users.tkk.fi/~ajhuovil/vst.html
>> >http://antti.smartelectronix.com/
>> >
>> >Didn't one of our guys write Vaz? Sorry I should
>> >remember....??
>> >
>> >Regards
>> >Tom
>> >
>> 
>> ---------------------------------------------------------
>> - Where merit is not rewarded, excellence fades.
>> - Hydrogen is pointless without solar.
>> - What good are laws that only lawyers understand?
>> - The media's credibility should always be questioned.
>> - The only good terrorist is a dead terrorist.
>> - Governments do nothing well, save collect taxes.
>> 
>> -- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
>> -- Linux Rex         | RedWebMail by RedStarWare
>> -- FatMan: home1.gte.net/res0658s/fatman/
>> -- NonFatMan: home1.gte.net/res0658s/electronics/
>> -- Autodidactic Master of Arcane and Hidden Knowledge.
>> 
>> 
>

---------------------------------------------------------
- Where merit is not rewarded, excellence fades.
- Hydrogen is pointless without solar.
- What good are laws that only lawyers understand?
- The media's credibility should always be questioned.
- The only good terrorist is a dead terrorist.
- Governments do nothing well, save collect taxes.

-- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
-- Linux Rex         | RedWebMail by RedStarWare
-- FatMan: home1.gte.net/res0658s/fatman/
-- NonFatMan: home1.gte.net/res0658s/electronics/
-- Autodidactic Master of Arcane and Hidden Knowledge.