Re: [sdiy] My New Project - PCSYNTH

[Scott Gravenhorst]

=?iso-8859-2?Q?Roman?= <modular at go2.pl> wrote:
>just take any ISA card, cut the traces from edge connector, and 
>solder some wires from there to vectorboard glued to the ISA 
>card. 

Now you're talking _DIY_...  Ok, I may consider that.  All I need is one 16 bit word...  Since I
won't need to allow the device to write to the buss, it should be fairly safe.  One 16 bit latch
and an address decoder is all I need.  That's an awesome idea, and you know, I was just thinking
how nice it would have been if they had done memory mapped I/O (what I call the Motorola method)
instead of that Intel port crap.

And I've got two sh!tty ISA cards that I believe are burned out anyway.  

I'll have to see if there are any memory holes in the first megabyte that I can use for this.  Heh,
probably the monochrome video adapter area.  That probably means I'll have to manually set up the
memory map for DOS with an XMS/EMS exclusion for the block used by the DAC.  (this is a Windows 98
box part time, I'd like it to still be able to do that job).

>Roman
>
>> >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. > 
>
>

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