[stella] Emulator Hazards

Subject: [stella] Emulator Hazards
From: crackers@xxxxxxxx
Date: Fri, 26 Sep 1997 23:39:37 -0400 (EDT)
Don't get me wrong. Using an Atari 2600 emulator on a PC is a big plus
for programming. It lets you see your results faster than going with a
real supercharger. But I've been discovering a few problems with relying
on an emulator only for 2600 programming.

1) Little mistakes that make you lose sync on a real 2600 often don't
   affect the emulator.

2) Emulator speed vs. real 2600 speed may be quite different depending on
   the type of machine you've got. Things that seem A-okay on my 486 are
   blindingly fast when played on a real 2600.

3) Colours look very different on a real 2600 as opposed to an emulator.

4) Default sprite positioning on the emulator isn't the same as it is on
   a real 2600. While working on my virtual pet I started my first two
   sprites out on the position they default to on the emulator
   (which is the far right hand side). Set up all my values to make them
   walk back and forth across the screen and when I played it on a real
   2600 everything was WAY off. The default sprite position on a 2600
   is actually about 1/3 the way in from the right. I suppose this is
   really my fault for being lazy. I should have put the sprite right where
   I wanted it from the start instead of relying on the default. But it
   seemed redundant at the time.

So you really DO need a supercharger if you want to be absolutely certain
that your programme will work as you intend it to on a real 2600.

In any case, I got all my bugs worked out and now my programme is working
as I wanted it to on supercharger and emulator (except, of course, much
slower on the emulator... I need a real computer). I've almost got the
video kernal finished, I'm still going over different ways to do the
stats screens but the critter screen is done. Once I settle down on a look
for the stats screen I can start work on the game logic.

There isn't much to these vertual pets, but my 2600 one will have a bit more
to it than the keychain ones. One of the advantages is the RAM to keep track
of the critters progress. With the keychain ones you can treat your pet like
crud and then satisfy all its needs just before it turns into an adult and
it will be the highest level. Mine will be able to keep track of how it was
treated over it's whole childhood.

I also think I may have found a way to attach a file to a message. I'm
going to try it out. If it works then my next message should have a
demo of what I've done so far. It doesn't do anything yet except
show the "need" sprite, "critter" sprite and "action" sprite (and the
critter sprite is dead to boot (and no he's not Kenny)).

I'm suprised I've gotten as much time as I have to work on this what with
the non-virtual baby having arrived. But my older son is at his aunts for
the weekend so here's hoping that I'll have more done by monday!

Also... for those of you out there who have been reluctant to programme
anything because you're intimidated by the difficulty of the 2600 or
a lack of machine language programming skill, there's really nothing
better than to just jump right into it and write a very simple programme.

Nick's "How To Draw A Playfield" demo code is a really good place to 
start as it shows you a simple example of how a 2600 draws a screen.
I was totally lost until I took a look at that programme and then
I began to understand the 2600 much better. And nothing will improve
machine language programming skills more than programming.

So just make a simple programme. It doesn't have to be a game or 
do anything fantastic. Just drawing a stable video image on the 2600
is something to be proud of.

And don't worry about making mistakes. I've been learning more about the
2600 from my mistakes than from my successes.

Also don't be intimidated by the presence of some really top notch
programmers on this list. They're all very helpful to new programmers.
They've answered all the many questions I've had on 2600 programming
in a kind and courteous manner.

So don't hold back, jump on in, the water is fine!

I tell you, I haven't been this excited about computers since I wrote
my first programme for the C-64.

                       (Having lots of fun from hell!!!)


Accordionist - Wethifl Musician - Atari 2600 Collector | /\/\
*NEW CrAB URL* http://www.hwcn.org/~ad329/crab.html ***| \^^/
Bira Bira Devotee - FES Member - Samurai Pizza Cats Fan| =\/=

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Current Thread
  • [stella] Emulator Hazards
    • crackers - Fri, 26 Sep 1997 23:37:08 -0400 (EDT) <=
      • Erik Mooney - Sat, 27 Sep 1997 10:02:29 -0400 (EDT)
      • crackers - Sat, 27 Sep 1997 15:30:02 -0400 (EDT)
      • Message not available
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        • crackers - Sun, 28 Sep 1997 14:17:09 -0400 (EDT)