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Sixer problems

Well, once again the folks at AtariAge are smart.

The usual cause of this problem is accidentally reading from a write-only register.  On many systems, this will return the address you are trying to read from, but some will give garbage.  But it's an easy mistake to miss:

lda #13 ; loads the value 13 into the accumulator
lda 13  ; loads the value at memory location 13 into the accumulator
; (which actually is a write-only register, so on some systems will accidentally load 13 into the register, but others will load garbage)

There's actually a setting in Stella (the emulator) that lets you force it to return garbage when reading from these registers, so by setting that flag, I can reproduce the problem that happens on the sixers.  And knowing what sort of typo to look for, I can probably sort this out relatively quickly.
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Atari Anguna: bugs on a sixer

First, a brief bit of Atari history:  The original Atari 2600s had 6 switches on the front -- the power, B/W, Select, Reset, and one difficulty switch per player.  Later models moved the difficulty switches to the back.  All the Atari versions now have goofy names that the collectors call them.  The original "heavy sixers" were bigger and heavier than the "light sixers" but both are sixers (having the 6 switches).  You could also have a 4-switch "woody" (that still sported the awesome late 70's wood-grain), or the darker "vader".  Or poor saps like me have the cheap little re-released Junior.

Well, I had only tested Anguna on my Junior, and a 4-switch woody (and in the Stella emulator).  It worked fine, so I figured we were good (theoretically, all the models are supposed to work the same).

Well, I just found out that that's not the case.  The main character doesn't animate correctly on the sixers.  I'm not completely sure what t…

Why retro games?

Recently my friend Bryan asked the question "Have you written before about what motivates you to create retro games?"

I've somewhat hinted at it a few years ago, but there's a few reasons:

Nostalgia is one piece of it. I grew up playing Atari and NES, and so the idea of being able to make a quality game for the system I grew up with is really fun.  As a kid, I wondered what it was like to make games for these systems, and spent hours sketching game designs on paper.  It's fun to finally get to do what I dreamed about back then. (I've wanted to make a NES game ever since the system first came out. After 30 years of preparation, I finally feel like I can pull it off!)

Another factor is the challenge, and how different it is from my day-to-day work programming.  I like programming, but the change of being so close to the hardware is a nice change..  The problems are somewhat similar to what I might solve at work, but really different in actual code.  And learnin…

Starting the next game

Now that Spacey McRacey is done, it's time to move on to the next game: a large adventure game for the NES.

I've had two ideas in mind for awhile, either my Blaster Master-style metroidvania game that I've talked about before, or another Anguna sequel.  After asking around to see if I could find any artists interested in working with me, I found someone that's interested in doing the Blaster Masteresque game.  So that's where we're starting.

First steps involve picking some technology.  On the Atari, unless you were going for some crazy advanced cartridge with a co-processor on board (which was really rare back in the day -- I think Pitfall 2 was the only commercial game that did this), all the cartridges boards are pretty similar, other than ROM size and the exact method of bankswitching to map all that ROM to the limited address space of the Atari.  (Ok, some also had some RAM on board. But still, there wasn't all that much that was different).

NES cartri…

Testing on hardware

Everytime I title a post like that, it's never good news.

We moved across town, which primarily means that I've spent more time fixing up an old house (to sell) and a new house (to live in) than I have programming for fun.  But I also had space to set up a nice desk space for writing/testing my games, including my NES and Atari attached to an old little tube TV (thanks, Jake!)

After hours of frustrating with faulty Compact Flash cards (remember those?), I finally got my PowerPak working, so now I can test my game on the real Nintendo! (as well as play all my NES games without fighting with dirty contacts every time!)

Well, as usual, it didn't go well at first.  Spacey McRacey was a jumbled mess of flickering as it scrolled. It bounced all over the place.

With some advice from the fine folks at, I had a number of things to try, but none of them worked.  BUT simplifying things by disabling my split-screen scrolling (the status bar at the top is locked into place b…

NESDev Results and more

Well, Spacey McRacey got 14th place out of 18 games.  Which is really about where it belonged; there were some really high-quality entries for this competition!   They're now in the process of trying to figure out how to build the competition multi-cart, which you'll be able to eventually buy, with all these games on it.

In other news, we're finally getting close to the Atari Age release of Atari Anguna. It's taken awhile to get all the boxes/manuals/etc printed, but it's almost there!

And I've got a partner lined up for my next game, which will hopefully finally be my dream of a Blaster Master-inspired metroidvania for NES.  Well see.

Spacey McRacey done

Well, I've submitted my game to the competition.  I think that means I'm done.  You can download it and try it from

Now that I've already submitted it, my PowerPak arrived in the mail.  So I guess I can go back and test it on hardware now that it's already done.  We'll see what happens.

Now it's time to start planning my next project!