djmips

I'm pondering selling my Cuttle Cart 1 - the one that has the audio interface and is Starpath Supercharger compatible. It's a decently rare cart it is in fair condition and is cart only. I'm wondering what I should set the price at? Anybody interested? Should I put it up on eBay? see http://en.wikipedia.org/wiki/Cuttle_Cart and http://www.schells.com/cuttlecart.shtml

I've had this as a bug in the past. A good reminder.

The following is equivalent to your code ; replace the lower 4 bits of var1 with the lower 4 bits of var2 (without changing the upper 4 bits of var1) lda var1 eor var2 and #%1111 eor var1 sta var1 and doing it that way means you could also ; swap the lower 4 bits of var1 with the lower 4 bits of var2 (without changing the upper 4 bits of var1 or var2) lda var1 eor var2 and #%1111 tax eor var1 sta var1 txa eor var2 sta var2 And that technique is covered in Hacker's Delight with three variations. The variation I used was © The nomenclature is the + in a circle is XOR ; three vertical bars is ! XOR; a bar over the mask is a NOT

I'm not sure where my copy of this book is right now. I think in a box but Hacker's Delight by Henry S. Warren was indeed a delight! http://www.amazon.co...n/dp/0201914654 Looking at the Matters Computational book there is some overlap but the scope of Matters Computational is huge! nice. Also saw that there was his home page http://www.jjj.de/ and a page on the book with more good stuff. This is really a gold mine and yes, I knew much of this already but it's pretty neat to see it collated and presented. http://www.jjj.de/fx...ge.html#fxtbook I have to admit I started to get overwhelmed because you referred to it as a paper. This BOOK is free but it's also available in print: http://www.amazon.co...e/dp/3642147631

I first saw a paper about this back in the 80s and they dubbed this approach a superoptimizer I've thought about it over the years, writing a superoptimizer for the 6502 but never tried. It would be pretty interesting. Batari took a crack at one back in 2005/2006 - I downloaded it but it ran under DOS so I never tried it, I wonder if anyone else has made one? The problem is embarrassingly parallel but there's a lot of territory to search, I'm thinking if you could get a 6502 emulator into a shader program you could use the GPU to parallel process the problem.

Cool

True all this is but the ARM is almost like alien sci fi tech that didn't exist back in the day. Maybe if you had a time machine. It is very cool and I love it but at the same time even you know that it isn't as pure as a 4K single bank game. From there you start to get foggier because even as soon as go to large ROM sizes you are starting to venture into uncommon (for a 2600 cart) areas. There is a dial and it's based on personal preferences but I say that the dial is at 0 for the 4K single bank game and then you could easily includes all the common banking schemes and extra RAM that was actually shipped in games in the original era. As far as the other end of the dial? Where does it stop... An ARM + FPGA? At some extreme point you slip into only using the 2600 for the joystick inputs and the video is coming directly out of a HDMI port on the cartridge...

Thomas, where would be ready to release the Elite demo source code?

it is cheating. don't give in to the dark side!

Jordan posted the source code for Prince of Persia (Apple ][ version) on Github earlier this year. blog post http://jordanmechner.com/blog/2012/04/source/ source https://github.com/jmechner/Prince-of-Persia-Apple-II There's also his POP technical document here -> http://jordanmechner.com/wp-content/uploads/1989/10/popsource009.pdf He has released some notes about POP development as an inexpensive eBook. http://astore.amazon.com/jordanmechner-20/detail/B005WUE6Q2

cool, watched and enjoyed that. Nice work on all your games.

Hey there. Very cool! Love it. Nice to see another bBasic demake. This one is much more complete and I like how you've worked with the limitations. The sound is very good, that's key. It's fun! - David Galloway Mega Man 2600 guy...

This looks fantastic. Geek note - I was super excited at a Game Developer Conference cocktail gathering back in March because I was unexpectedly in a small group that included Jordan Mechner. We talked a bit about Karateka and Prince of Persia. I'd bet he'd be well impressed by this work you've done! They others in the group were the developers of Limbo which is another game everyone should try. Keep up the great work.

Yes, I took VDUB's kernel plus Dan Boris's reverse engineering of the 1972 PONG and made a version that looks and plays like the 1972 arcade version. I think there's another thread with a more up to date version somewhere else and I have a more complete unposted version on my computer.

Everything is well for me. Turmoil would be the quick way to describe the last year. I moved back to Canada (Vancouver) and started a game company with a friend. Things went great and the game is coming along nicely, however, funds were limited and now, to pay my bills, I'm working back in 3D rendering programming at United Front Games in downtown Vancouver. I don't have a 2600 'project' right now. I have been spending time doing some odds and ends for the NES and for the Propeller embedded system. Most of my time in the last few months has been completely soaked up by the incredible challenge of working out a great renderer for DX11 that properly harnesses all of the CPU cores and the powerful GPUs whilst maintaining backwards compatibility with DX10 cards and older CPUs.

(I have no idea what he is talking about! ) To have an idea what he is talking about... well, when you are finished Ballblazer. Go check out this talk. http://www.pagetable.com/?p=53 There is a video somewhere there as well. Ah just go check it out. Also the 6502 talk http://www.pagetable.com/?p=517

That macro is a total 'waste of time' Hahaha actually pretty cool. Thanks. I'll add it to my quiver.

Yes, it is exquisite. Work of art.

I was curious how you planned on putting in the goal posts and ball?

If you want to try your hand at NES programming the easiest package that I've seen is the KNES library for CC65. http://kkfos.aspekt.fi/projects/nes/knes-library-for-cc65/ Very easy to setup. Good sample code in C. Works. And you can drop into 6502 when you want. I tried it and had it up and running within an hour. If someone needs help getting it working just let me know.

I've developed a few games for GB. It's been awhile. The CPU is an 8080 not a Z80. I used sdcc as well as assembly. The no cash emulator/debugger wasn't to bad. He made some custom opcodes so you may print to a window. That allows for some decent 'print' or trace debugging. I have some good library code somewhere. I wrote a sprite 'system's etc

Not that I am aware of. IIRC some people did some experiments with RSYNC, but to no success. But you can circumvent the problem in multiple ways. E.g. if you compare Vanguard's with Thrust's horizontal PF scrolling, the later does look much better (IMO ). Or you can try do use e.g. the ball for edge smoothing, or maybe even flicker the edges. I do like the delayed scrolling in Thrust which is an elegant approach given the coarse horizontal resolution of the playfield. Have you ever seen someone do a demo of playfield scrolling using the ball for edge smoothing? I think it would be a neat trick for sure. You would have to do leading edge and trailing edge so your design would have to accommodate that on each line you would have enough time and resources to cover up the leading edges and trailing edges for the entire width of the screen. I'm seeing your flicker the edges idea in my mind's eye as a form of anti-aliasing or time division multiplexing or pulse width modulation, and I can see how that would work but I don't think our eyes would be able to integrate this without some very irritating flicker side effects and I'm not sure it would be successful at conveying the smoothed edges appropriately. But the only way to find out... :-) But getting back to the RSYNC idea. RSYNC is documented as Reset Sync - resets the horizontal sync counter to define the beginning of horizontal blank time, and is used in chip testing. <- From Stella Programmer's Guide. Really? chip testing? RSYNC is also described in Andrew Tower's TIA Hardware Notes where he has discerned the function of the TIA partially using some published schematics. Here is Andrew's description: ref: http://www.atarihq.com/danb/files/TIA_HW_Notes.txt H@1 and H@2 are the two phase clock for the TIA which uses the 3.58 Mhz Color burst divided by 4.

You're welcome. Yeah from the descriptions sprites beyond the vertical borders required more precise timing compared to the top/bottom. This would tricky like a lot of 2600 programming. Nice C64 game. Wow your game is old school difficult like 'Crazy Balloon', 'Irritating Stick' or 'Marble Craze'. I hope that when you fail you have to start at the absolute beginning? Anything else would be a disappointment. :-) What do you think are the best / smoothest HORIZONTAL scrolling 2600 games?