Re: cool article, interesting quote
- From: Rich Grise <richgrise@xxxxxxxxxxx>
- Date: Fri, 28 Apr 2006 16:37:51 GMT
On Fri, 28 Apr 2006 01:14:12 +0000, joseph2k wrote:
Keith wrote:
On Sun, 16 Apr 2006 15:42:21 -0700, John Larkin wrote:
On Sun, 16 Apr 2006 22:14:47 +0000 (UTC), kensmith@xxxxxxxxxxxxxxx
(Ken Smith) wrote:
John Larkin <jjlarkin@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
[....]
Could any post-1970 CPU architecture be much worse than the 8048/8051
horrors?
IIRC, the RCA 1802 was after 1970. It makes the 8051 look advanced.
Actually, I don't think the 8051 is all that bad. As a CPU it's a mess of
asymetric instructions, but the hardware attached to it is rather nice.
All of the address spaces (as opposed to modes) are kinda hard to get
one's arms around but it all comes together. ...eventually. ;-)
I've done several projects with 8051s, embedded in $25M mainframes and
exposed to customer executives, high enough to trusted with the bank's
(in three cases FRB's) crypto master-keys), even.
Actually the 1802 has some really nice features, including an any use
register set, a regular instruction set ala RISC, and a few twists if you
can learn how to use them. It also happened to be relatively rad-hard as a
byproduct of the design and implementations. This is why it is in a lot of
satellites in preference to a lot of competitors.
I've never used an 1802, but if it's nostalgia week, one of my favorite
"small" micros was the 6502. 256 working registers, called "page 0", and
orthogonal, symmetrical instructions - the only drawback is that the stack
was fixed at 256 bytes on "page 1". Made a dandy encoder for a raw
keyboard, had N-key rollover and everything.
I've also done 8051 (8035, actually), and didn't like the timer at all,
but I was able to make it work.
Cheers!
Rich
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