[geeks] arcade collectors?

[Ken Hansen]

Not a hardware guy either (at least at this level), but I do remember that the early CPUs (and, I assume, current CPUs do as well) provided for "pairing" registers to accomodate data larger than the wordsize of the CPU.

Ken

-----Original Message-----
From: Brian Hechinger [mailto:wonko at arkham.ws]
Sent: Friday, June 29, 2001 2:08 PM
To: geeks at sunhelp.org
Subject: Re: [geeks] arcade collectors?


On Fri, Jun 29, 2001 at 01:55:05PM -0400, Joshua D. Boyd wrote:
> 
> Seems to me that MAXINT for an 8bit CPU should be 127 or 255.  Otherwise,
> it is usuing larger than 8bit registers, and that would mean that it
> wasn't really an 8bit CPU (IMO).  But, I've never tried hacking anything
> less than a 16bit CPU (8088 to be specific).

hmm, should i research this or talk out of my ass?  i'll talk outta my ass. :0

<mode="talk out of ass">

i'm not hardware pro or nothin, but do your registers need to be INT wide?
why not use 16bit INTs and 8bit regs, you only put stuff in regs if a) they
are 8 bit and b) you have an immense need to.  besides, if this thing is 6502
based, i thought regs were implemented in RAM, so you could therotetically have
16bit regs on an 8bit CPU.

or you could fake 16bit INTs in software, but that would probably cause
obnoxiously slow performance.

i could swear that most machine have instruction and mem sizes that differ, for
example 32-bit CPU with 64-bit mem addressing, could you actually do 64-bit
INTs on something like that?

</mode>

anyway, tear that apart and see what you come up with.

-brian
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