long term computers

From: Jim Brain <brain_at_jbrain.com>
Date: Sat, 26 Feb 2005 17:56:55 +0000

Ben Franchuk wrote:

> Ronald Wayne wrote:
>> On Sat, 26 Feb 2005 12:49:19 -0500, Mike <kenziem_at_sympatico.ca> wrote:
>>> http://d116.com/spud/
>>> this one was referened on the theregister recently
>> Ah yes, somebody was showing me rfPICs last year. Just imagine a
>> wireless webserver the size of a match head. :)
>> I remember thinking at the time, 'how does this thing compare to an
>> Apple II?' Of course the guy showing it to me didn't have the
>> slightest idea because he didn't know what a 6502 was.
>> So perhaps I should ask here: how would your typical 2005 vintage PIC
>> compare to a early-1980's vintage 8-bit microprocessor? From what
>> little I could gather the interface with the outside world is terribly
>> limited (something like four lines on the chip I was looking at, one
>> of which was special purpose) but that is slightly negated by the
>> thing having an, albeit miniscule, amount of memory on chip.
> From what I remeber from a quick look at them on the web looking for
> other stuff:
> They tend to be small-ish RISC computers. 128 bytes of ram
> 2k of rom and some I/O pins ... Hey wait that sounds like PDP-8
> again -- have we come full circle?
> Ben alias woodelf
A note that the Xgamestation uses a Ubicom SX52 (PIC compatible
instruction set, 80MHz operation.

For sheer speed, the newer parts win. The SX52 and some of the faster
PICs, for example, can emulate a complete 1MHz 6502 entirely in SW.

However, they have a number of limitations. Very small stack (SX has 1
level, I think PIC does as well), no self-modifying code (not a terrible
thing...), very limited access to RAM. Small code storage size.

It's probably more fair to compare the Atmel AVR 8-bit RISC line to the
6502. AVRs clock to 20MHz, have the ability to access 64kB of RAM in
one chunk, 128kB of code space, and suitable stack size. Still no
self-modifying code, but the rest stacks up well.


Jim Brain, Brain Innovations
brain_at_jbrain.com                                http://www.jbrain.com
Dabbling in WWW, Embedded Systems, Old CBM computers, and Good Times!
Received on Sat Feb 26 2005 - 17:49:20 GMT

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