-=> Mike Ross said to Greg Mayman
 -=> about "THOSE OLD EXPENSIVE [1/2]" on 01-04-03  22:34.....

 MR> I could never understand the point of an Eprom emulator. I mean if the
 MR> program works why not simply burn the eprom and be done with it. If it

Of course, if it works, it would be stupid to do anything else.

 MR> has a bug then simply erase the eprom and start again.

That word "simply" as in
(1) simply put the EPROM in the UV eraser, switch on, wait 20-45
    minutes (depending on the eraser),
(2) simply plug the EPROM into the blower, and blow it,
(3) simply plug it back into the equipment and try again.

That is not counting the time it would take to work out where the
software MIGHT have gone wrong and write a correction that MIGHT
work, although this could easily overlap the erasure time.

What we are talking about here is half an hour MINIMUM just to
check out one single change, to see whether it has fixed the bug.

 MR> Why the need for an emulator that may cost hundreds of dollars?

Because to track down a bug may take MANY "change-this-and-try-
it" cycles, often 20 or 30 or more in the case of software that
runs to only a few hundred bytes.

It also helps to be able to halt the program at various points so
you can check that each part of the code is working properly,
rather than let it all run and try to guess which stage it is
going wrong. So that means add breaks temporarily to the code,
and removing them later.

What you need is a way to change one thing and try it RIGHT AWAY,
and if it doesn't fix the fault change something else and try it,
and so on.

One emulator that is listed in the Radio Spares catalog lets you
do just this, changing stuff "on the fly" and testing it
IMMEDIATELY.

Then when you've got it right, you can blow an EPROM with code
that you KNOW will work.

This beats repeatedly inserting an EPROM and removing it so you
can erase and reblow it, and then having the pins get damaged
before you're done!

From Greg Mayman, in beautiful Adelaide, South Australia

... Violence is the last resort of the incompetent - Lorne Bozinoff
___ Blue Wave/386 v2.30

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