Re: [cosmacelf] Re: I hate PICs.
- Doug Jackson wrote:
> My name is Doug Jackson. I have been active in the microcontrollerWelcome, Doug. Good to hear from you! My early microcomputer career was
> arena since 1982.
much like yours, and included TRS-80 model 100s and various 8080 and Z80
CP/M machines, as well as the 1802.
Later, I've used PICs and other newer micros in many projects for work.
At work, it's all about cost; they don't care how bad the micro is or
how expensive the development tools are as long as the end result is cheap!
> I have to admit that when I am solving a problem, I tend to useThere's no question that for professional engineers, the PICs makes
> whatever tool fits, and I do use a lot of PIC micros... Programming
> them is trivial - The instruction set is a bit bizarre, but that's
> what the compiler is for.
perfect sense. The problem is that if you were a teenaged kid, without
the years of experience or budget for development systems and software,
the PIC is a very difficult chip to get started with. They don't know
any programming languages, and as of the last census, only a little over
half of US households have a "computer" (which includes all types, many
of which are not suitable as microcomputer development systems).
If we expect to have software and hardware engineers in the future, we
need to have ways for them to get started early. Not wait until they are
in college, or working for some big company.
> For the ELF, you just need the ELF itself, but if I try to embed anFew ELFs had EPROMs. Most often, programs were stored in RAM, and stayed
> 1802 in a project, I still need something to program an EPROM, as well
> as the logic on the project to allow the 1802 to see the EPROM and the
> memory device. A solution that should have been solved with one
> component needs 4 at least.
there until you turned off the power. Programs were loaded by hand, or
from cassette tapes. The most common display device was an ordinary TV
set. You didn't need to know anything about programming; you could learn
as you go. The idea was that once you had the ELF, all you needed were
things you already had in the house, so the barriers to getting started
were as low as possible.
> As far as Forth, I have had renewed interest in Forth on the PICs - InI'll check it out. It must be entertaining how they run FORTH (which
> fact our sprinkler controller at home is built using a PIC 18F4455,
> running forth. Have a look at PICForth.
depends heavily on stacks) on a PIC (which effectively has no stack).
FORTH, Logo, and BASIC are all excellent "first" languages for
beginners. Assembler is tougher, but the 1802 is about as simple as they
I think PIC computers are fine for beginners *if* there is a high level
language to hide the horrors of PIC assembler. The Parallax BASIC stamps
accomplish this with their BASIC (which isn't really all that BASIC).
Novices pay $50 for a BASIC Stamp because they don't know C or assembler!
What I'd like to see is something physically like the BASIC Stamp (all
one "chip", even the power supply), but with some sort of front panel
interface so no PC is needed. And, with either a simple enough
instruction set, or a built-in high level language so beginners with no
programming experience can get started and learn it quickly.
The old $49 Sinclair ZX80 computer was about as close to this as I think
we've been. It had a Z80 CPU, ASCII keyboard, video output for a TV set,
audio in/out for a cassette recorder, and built-in BASIC.
Lee A. Hart | Ring the bells that still can ring
814 8th Ave N | Forget the perfect offering
Sartell MN 56377 | There is a crack in everything
leeahart earthlink.net | That's how the light gets in -- Leonard Cohen
- CamelForth looks interesting. It seems to be designed specifically for small implemented microcomputers.
I was looking at the source and it seems to be really well written code. It is documented well and has a number of nifty additional WORDS including some debugging ones.
--- In firstname.lastname@example.org, jporubek <jporubek@...> wrote:
> Very good summary of the current state of the hobbyist micro world,
> Mark. I'm usually a lurker in this group, but I couldn't resist the
> urge to weigh in with my opinions.
> I, too, don't particularly care for PIC micros and I'm not entirely
> sure why. Maybe it's because the original chips had next to no
> hardware support for a decent stack. I'm a big fan of programming in
> Forth for micros, and you can't do Forth without a real stack. Or
> maybe it was the weird, non-standard assembly language mnemonics,
> especially if you were used to the 6502/6800 style of mnemonics (or
> even 808x mnemonics). I know that PICs have come a long way since
> those early days, but I still feel a small sense of disappointment
> when I read an article in Circuit Cellar and discover that the project
> is based on a PIC. It's also a big reason why I keep telling myself
> I'm going to let my subscription to Nuts and Volts run out next time
> it's due.
> Like most people in this group, I got my start in micros with the RCA
> 1802, building my own improved version of the ELF with muxed data AND
> address displays and a hex keypad. I was enamored with all things
> COSMAC and acquired a VIP, a Studio II, and even an RCA Micromonitor.
> I then progressed to 6502-based computers with an AIM-65 and a
> Commodore 64 before assembling my first PC. I dabbled a little with
> the 8085 via a Radio Shack Model 100 and a Kyocera 85. I'd like to get
> back to all of them someday as part of my own mini-museum - maybe if I
> can ever retire!
> I like AVRs from what I've read about them, although I don't have any
> hands-on experience. A brief professional exposure to an 8051 project
> was painful, although this may not have been the 8051's fault - it was
> being over-taxed with bank-switched memory and the code I had to
> interface with was badly-written C spaghetti code. I have mostly
> pleasant experiences with 68HC05s, 680x0s and Coldfires.
> However, my current processor of choice is the TI MSP430. In some ways
> it could be claimed to be the cultural descendant of the 1802. Like
> the 1802, the MSP430 is designed for low-power applications, although
> modern semiconductor process technologies make the MSP430 a far lower
> power device than the 1802 could ever have hoped to have been. Like
> the 1802, the MSP430 architecture is based on 16 16-bit registers,
> although the program counter and stack pointer registers are fixed for
> the MSP430, unlike the 1802! There are versions of Forth available for
> both the MSP430 and the 1802 at http://www.camelforth.com There's
> even a version there that I ported for the TI eZ430-RF2500T low-cost
> USB stick development tool.
> Mark, your website looks really interesting, especially your
> 8085-based micro trainer. I plan to spend some spare time looking
> through all that's available there. Thanks for putting it up on the