PC/Apple/etc. Cards Worth Keeping/Storing

[Tony Duell]

> 
> Tony Duell wrote:
> > There was no separate TechRef for the CGA card. The hardware is covered 
> > in the normal Options and Adapters Techref. 
> 
> ...which I don't have :)  Oh well, hopefully there's electronic copy somewhere.

I've never seen an electronic copy of any of the Techrefs, I am not sure 
if IBM would explode if somebody started distributing them, either. 


> 
> > It's supported by the 
> > standard mainboard BIOS, the source lising of which is in the 
> > machine-specific techrefs.
> 
> I don't have that either, but I've disassembled my own BIOS and found that it 
> is nearly useless to me -- for example, there are instructions that take longer 
> to execute out of RAM (4 cycles per byte opcode) than ROM (2 cycles) -- so it's 

Rememebr the true-blue IBMs didn't shaddow the ROM. The BIOS ran from ROM 
all the time.

But the BIOS code is often pretty badly written. The RS232 driver in 
particular is a good example of how not to do things!

To be fair, I have much the same comments about the hardware. When I got 
my TechRefs, I went through all the schematics, and exclaimed at 
approximately 2 minute intervals 'They did WAHT???'

-tony