Dionoid

Hi Darrell, thanks for the explanation on data streams. Question: what is the role of the DSCOMM data stream when moving data between 6507 and ARM, in context with DSPTR and DSWRITE? Another question: for my first CDJF project I've been pushing the limits of the ARM chip until it wasn't able to finish before the end of the VBLANK. I had to find out on real hardware, as I understand Stella doesn't take the ARM cycles into account. While I fixed the problem by optimizing my C code, I find it hard to figure out how much 6507-cycles my ARM code is actually burning. What do you normally do in a case like this? Thanks, Dion

And great decision to do the new Boulder Dash as a unlimited run, so that the original run (limited to 200 carts) still keeps its value.

It looks like there is still work to be done on the FPGA-implementation of the Atari 2600 in the Collectorvision Phoenix. From the short test on ZeroPage Homebrew's stream, I could see that even simple games have annoying glitches. Things I noticed : CTRLPF score-mode is not supported (i.e. where the left half of the playfield gets a different color than the right half) 48-bit sprites are messed up (i.e. where both player graphic registers use 3 close-copies to create a 48-bit wide sprite) If even these basic things don't work correctly, I doubt if this FPGA-implementation is ready for prime time. I think the MiST implementation of the 2600 has the same issues, so maybe this was copied over to the Collectorvision Phoenix?

Yes, I came across his port in the AtariAge forum. Impressive work, as the Arcadia Supercharger is not easy to program. However the tiles are using a single PF-pixel, and player graphics are only 4/5 pixels wide, which IMO doesn't look great on screen. Anyway, let's see how my version turn outs. At the moment it's nothing more than a rom showing a static screen, so I guess I have put my money where my mouth is 🙂

Below is a Stella screenshot of the CDFJ-game I'll be working on after I finish Tower of Rubble. The working title is "Fool's Gold", and it's a port of one of my favorite games on the Commodore 64. I wanted to make this port for the '2600 some time ago, but until now I didn't manage to cram it into a 76-cycle kernel and 128 bytes RAM (or even a Superchip with an additional 128 bytes). It's only a proof-of-concept for now, just to see if I can have the ARM create data streams for an asymmetric playfield. Apparently it works 🙂 About the "J" in CDFJ: I met John Champeau at PRGE 2019 just a couple of weeks ago, and he got me interested in CDFJ by giving me a 10 minute crash course. After that he provided me with a small CDFJ test solution, which basically shows the famous '2600 rainbow screen and a sprite that can move up and down.

This is very, very good news. Boulder Dash was one of my favorite games on the C64, and I can't wait to play the game on my '2600. Thanks for making this happening, Andrew and Thomas!!!

Here is an index to all the DPC+ARM blog posts by Darrell: DPC+ARM - Part 1, Virtual Machine and Linux DPC+ARM - Part 2, Guest Additions DPC+ARM - Part 3, VirtualBox update, Ubuntu update, disable Screen Lock DPC+ARM - Part 4, Cloning DPC+ARM - Part 5, C Compiler DPC+ARM - Part 6, DPC+ Cartridge Layout DPC+ARM - Part 7, 6507/ARM Exchange of Information DPC+ARM - Part 8, Multiple Functions DPC+ARM - Part 9, Functional Menu DPC+ARM - Part 10, Score & Timer display DPC+ARM - Part 11, Beginnings of the Arena Kernel DPC+ARM - Part 12, Gamepad Support Note that Parts 1 - 5 are about setting up a VM with the ARM compiler, which is probably outdated now. Maybe someone can create a Docker image containing a ready-to-go DCP+ARM development environment? And some other interesting related posts: The C RAM Review It's full of stars! Slick Kernel

Never mind my question on differences between DPC+ and CDFJ; I think this post by Darrell explains it all. And there is a wealth of posts by Darrell on DPC+ARM, which I just discovered and will read into the coming days. Great stuff!

Hi Darrell, thanks for starting this overview on CDFJ! After finishing my current game (Tower of Rubble), my next game will be using ARM, so the timing of your posts on CDFJ is perfect! 🙂 Two questions: I assume that second 2K (for C code and data) goes from $0800 - $0FFF, not $0800 - $1FFF. A typo, right? The difference with DPC+ seems to be the smaller ARM driver, leaving more ROM for your game, right? Are all the blogposts on DPC+ still valid, or is CDFJ different on essential parts? The CDFJ acronym is really hard to remember; too many consonants. Maybe call it DPC-2 🙂 ?

Hi Darrell, thanks for the great info! I'm on Windows, which also works fine for compiling. JohnC helped me setting up my dev environment, for which I installed some GnuWin32 tools like make, grep, awk and the core-utils packages (which contains commands like 'rm') What is the benefit of using the Linaro ARM compiler, instead of the 'GNU Embedded Toolchain for Arm' from https://developer.arm.com/ ? I tried both, and both seem to compile the example. Is it only about the size of the resulting ARM bytes? Thanks, Dion

Portland Retro Gaming Expo 2019 was a blast!! It was a pleasure to meet Albert and his wife, John Champeau and his brother Paul, and of course James and Tanya from ZeroPage Homebrew. Here are some photos of Amoeba Jump being sold at the AtariAge booth. The box and cartridge labels look great! Thanks to Nathan for the artwork and Albert for the high quality printing and cartridge production.

A new version of Tower of Rubble is now available. This is the exact same version that was demoed at the AtariAge booth on PRGE 2019. New in this version: Two player simultaneous mode! (press the 'select' button until '2 player vs.' appears in the middle of the screen) Players can not pass each other, so you can block the other player in order to get him/her squashed by a falling piece of pebble or one of the laser beams 🙂 The first to score 10 points, wins! The game now slowly ramps up, so in the beginning you're always able climb neighboring blocks (thanks to @Thomas Jentzsch for the tech suggestion). And: the higher your score, the more difficult it gets! The game ROM-size increased to 8K (using bank-switching), as I need the extra space for two-player mode (including player-vs-AI) and things I'll be adding to the game in the future (extra sound fx and text). I'm open to feedback/suggestions, especially on the two-player mode! Download the latest v0.4 version from the original post here:

Seller is still offering these illegal homebrew carts on local eBay: https://www.ebay-kleinanzeigen.de/s-bestandsliste.html?userId=51058993 I've reported the item; let's see if eBay kleinanzeigen does something about it.

I also reported that one. How long does it usually take for eBay to take action on reported products?

That's really clever! I never would have thought about using a RAM-based dumper and storing it on a SaveKey. Steps 2 and 8 are kind of a mystery to me: How did you know what bankswitching scheme PP was using? And if that bankswitching scheme was unknown until now, how do you get Stella to understand and run it?

Hmm, I think the rule-blocks will be more difficult to use if the words are not written out. Maybe I'll give it a try sometime; for now I've too many projects on my To Do list already 🙂

I was just playing the popular Indie puzzle game 'Baba Is You', which I think would really fit this '2600 tile engine. https://hempuli.itch.io/baba-is-you

Yes, please! I'm a first-time attendee. Name: Dion Olsthoorn AA Handle: dionoid Location: Leiden, The Netherlands

@Albert I'm going to change my plans and visit the PRGE this year; I got green light from both work and my family! 🙂

August is also not very convenient for me. Bummer. @Albert: do you also sell PAL cartridges on your booth at PRGE? Or is it NTSC only?

Portland Retro Gaming Expo 2019 is getting close, and so is the official cart-release of Amoeba Jump! I don't have a bucket-list, but if I had one, it would certainly contain "- Make an Atari 2600 game and get it released on physical cartridge and with a nice box" Thanks to Albert and Nathan for making one of my dreams come true. You guys rock! I'm planning on going the PRGE next year in 2020, so it would be nice to meet some AtariAge friends then! Here is a peek at the box for Amoeba Jump. Nathan Strum's artwork caught the spirit of the game very well.

Excellent suggestion, Nathan. Work in progress... In the coming release this "player vs. AI" will be disabled, as I want to keep that feature exclusive to the cart release.

Hi, I noticed that the Stella emulator shows a refresh-rate of 59.5Hz when running PAL60 games. While I assume that is the correct refresh-rate, I don't understand the reason for this. Where is that .5Hz lost?

The brothers Gary, Dan and Steve Kitchen all worked at Activision for some period of time; pretty unique.