> > A very simple circuit is something that can be made quickly and
> > without too many components on a piece of board (the one with a lot of
> > holes pre-made in it)
> > dics
> 
> Most PIC programmers are pretty close to "very simple".

Agreed.

> 
> As others have pointed out, you can't get a programmer to program "all"
> PICs, but most of the circuits out there will program most of the PICs.

Also there is some debate about the necessity of needing to program
every PIC available. Many times one can get away with only tackling a
subset. For example programming only flash based parts.

> 
> There are really two kinds of programmers, the simple, and the not so
> simple.
> 
> The simple programmers are nice because they are supported by a wide range
> of free software.  Unfortunately, free software isn't always all that well
> supported, so when a new PIC comes out, you may have to wait a while until
> it gets supported, and you will have to do some hunting around to find the
> program that works with your programmer and the PIC you want to program.

Bingo. I'm trying to get out of the programmer software business and
leaving it to PikDev for Linux boxes.

> The other downside of the simple programmers is that they will not work with
> a USB port, even with a USB to serial converter.  As more and more PCs come
> without serial or parallel ports, this gets to be a bigger and bigger
> problem.  Further, more recent versions of Windoze make it hard to work with
> the ports directly, so you may have a hard time getting the software to
> work, or it may require you to do things that risk your system's security in
> order to make the programmer work.

Nice sharpshooting John. In addition with USB serial ports there are no
guarantees that you can syncronously control the modem control signals.
The only guarantees that you can make is that you can use the driver to
set and unset modem control signals, and that TX and RX work as per a normal
serial port. Other than that all bets are off.

So there are no guarantees that a NoPPP or JDM style programmer will work
with a USB serial cable.

I plan to get back to prototyping my Trivial BootStrap 555 PIC programmer
that's specifically designed for using only TX and RX which should guarantee
that it'll work with. My starting prototype is here:

http://www.finitesite.com/d3jsys/tbs555

But it is neither finished or fully tested. Another design along the same lines
can be found at www.piclist.org here:

http://www.piclist.org/techref/com/picnpoke/www/http/projects/prog.html

But at the end of the day it is going to be tougher.

BTW neither of the two programmers listed above would be for regular use.
They would specifically be designed to get a bootloader loaded or to move to
stage #2 below.
 
> The not so simple programmers have a PIC on the programmer.  The problem
> with this is that you now need to have a pair of programs, one for the PC
> and one for the PIC.  In general, this means that you are at the mercy of
> the supplier of the programmer.  Sometimes (as in the Wisp628) you can get
> the source, so depending on your programming skills you might not be totally
> at the mercy of the supplier, but when you want support for another PIC,
> then you either need to convince the supplier to add it, or you need to go
> buy a different programmer.  To an extent, this is even true of the pricey
> programmers from Microchip.

IIRC Olin's EasyProg had a mode where one could send bit-twiddle commands
so that it's possible to program new parts without changing the firmware.

> 
> If I were in your shoes, I would probably go build a simple, Tait-style
> programmer, grab a copy of WinPic (the one from DL4YHF), and try to be
> content with the list of PICs that are supported. But I have to admit, it is
> awful tempting to just go buy a Wisp or EasyProg (they're not very
> expensive) and let Wouter or Olin deal with the hassle of chasing after the
> programming algorithms.

Agreed.

BAJ
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