Hi itsmoked and originator-
Hi itsmoked. No, it was the Carl's Jr. on Homestead in
Sunnyvale, but I know the Jack in the Box on El Camino!
If I remember my computer lore correctly, the guy that
designed the 8080 "jumped ship" and went over to Zilog to
create the Z80 CPU. THAT's very fuzzy in my memory so
that could be an urban legend.
Also, again if memory serves me right, the 8085 extra two
instructions were SID and SOD (serial in and serial out).
Not to a uart, but a pair of pins on the chip. And the
8085 was MUCH different than the 8080 hardware wise. It
used a multiplexed data/address bus. In some ways it
was easier than the 8080 designs.
Originator. Congratulations on the parallax. I went a
slightly different tack on my microchip stuff. I believe
that the "stamps" are PIC based with a little basic
interpreter. I could be wrong and someone please correct
me. However, I looked at the price of the stamps vs. the
cost of a plain pic available from Digikey, Mouser, or
a whole host of mail order catalogs. Microchip at the
time (and still may) gave away 5 PICs for people to play
with (although it took a LONG time to arrive in the mail).
The standard PIC that I use now is a 16F648A. They are
under $2.00 each in quantity 25 (the number that I usually
buy at one shot). I started out with the 16F628 and
home rolled a little programmer for it that uses the
parallel port of the PC to program. Maybe as mentioned,
the microchip assembler and simulator is free from the
microchip site.
The 16F6XX class of PICs are 18 pins, have an internal
clock so no crystal or resonator to mess with. In fact,
other than I/O, all you need is a small cap (0.01 uf)
across the supply pins and optionally a 10K pull up for
the reset line (optional, some programmers use RA5 as
an I/O rather than MCLR, mine doesn't). I use standard
push in proto boards for quickie designs and as a basis
for downloading (programming) the pic's flash memory.
So, with my laptop, a little 5V wall wort, and ICD2
(mentioned later), I can go do a lot of design at a
Starbuck's coffee shop (I've graduated from Carl's, no
power) and have some nice iced tea, have a nice window
to look out of, and people to chat with. Cheaper than
renting an office for sure. Add a logic probe and or
a little USB logic analyzer and I can do hardware debug
there too! Truth to tell, I haven't dragged the logic
analyzer out of the pouch at Starbucks (yet). But it's
there if I need it. Shoot I even do my PCB layouts there
now with the laptop. No more sitting in front of a $25K
workstation using Mentor for me!
Anyway, back to the pics.
For about $2.00 the chip then becomes a logic replacement
element and you can just about use them everywhere. One
wag said:
"Why use a 555 timer when you have a PIC!"
I use the assembler a lot, but I'm a grizzeld old fart when
it comes to programming. I've done Harvard architecture
programming for just about as long as a Von Neumann
architecture machines (that's why the PIC architecture is
so "bad").
However, after learning to use the assembler in little
projects and gaining confidence with the toolchain, you
might want to go to a C compiler for additional ease in
programming. I personally use the cc5x free compiler,
although I've heard good things about the free C compiler
from microchip (the other ones mentioned in the list I
don't have experience with). My choice for the cc5x was
that although they don't have "free" versions that generate
object modules greater than 1K words, they allow one with
a bit of dinking around, to LINK the modules for the full
8K words found in the standard "MAX" 16F series of PICs.
Another very popular PIC is the larger 16F877(A) chips.
These include much more I/O and 8 channels of A/D along
with the aforementioned 8K words of flash program store.
These require a crystal or resonator to operate with.
I typically buy these a couple at a time for about $7.00
each. Most of the time in 40pin DIP. All the pics have
various package designs, with surface mount and lead free
available. For prototype work where space is not an issue,
the DIPs work fine for me.
My final pic that I use is the 12F675. My "little guy".
No UART on them, but 3(4) channels of A/D decent ram and
for me, an 8 pin DIP configuration. Again, no crystal
and use the internal oscillator.
So, I have my 3 models and know them all pretty well. A
mini, midi, and maxie pic to choose from. There are
hundreds of different PICs available. One can go nuts
trying to learn them all. I suggest picking a couple and
learning them. Get to know them well, then if you have
a need for a different one, go to the new one as needed.
I personally "graduated" to an ICD2 debugger/programmer
but you might be just as happy doing the "raw" debug
mode (which you will find out about later). The ICD2 is
about $150 from Microchip (there are, I'm told, cheaper
knockoffs out there). I had to do a design for a
customer who wanted to program his pics and fab his own
boards. No problem. The design however, worked out best
with 2 pics in it, communicating with each other. So,
I got two of the ICD2s, one for myself and one for the
customer. I left one for him to do his programming with.
Saves a BUNCH of time.
There are even more expensive debuggers offered by
microchip, but I tend to only buy the tools that I need.
Again, YMMV.
Finally, there are some very good support groups for the
PICs out there. Two that come to mind and ones that I
monitor are the yahoo pic list:
although, of late, it's been much slower than it used to
be. I read the MIT piclist from gemane reader rather than
having it as a mail group. This is a group with some
real great contributors and although sometimes off topic,
there is good information to snoop through. My link and
reader for it is:
Of course, you can always ask questions here.
We oughta do a FAQ on this subject..... Sigh. Seems
like I remember writing this a time or two.
Best of luck. Keep us informed.
Cheers,
Rich S.
