jdrose

There are answers in this thread that may help you understand mirrored addresses better. http://www.atariage.com/forums/topic/192063-old-timer-new-to-2600-programming/

Very cool. http://www.flickr.com/photos/shee_rah77/2549473027 http://www.flickr.com/photos/redmeg8/4195480646 http://www.flickr.com/photos/cloudbustr/130977012 Computer: http://www.flickr.com/photos/laceyg/1528000599

That is good news, I have around 750 bytes free. What is the best way to convert a sample recording to 4 bit data suitable for the 2600 routine?

Regarding the VCS: I have never seen a comma between the 2 and 6. It's not a dollar figure. "Twenty Six Hundred" is the way to pronounce it. Cheers!

This is a difficult store to navigate but I did find a TIA listed. Might give them a call. (CO104444D - UM6525N ("TIA" 2600)) http://www.best-electronics-ca.com/custom-i.htm You may want to invest in a digital probe. Affordable, handy and easy to use. You are basically looking at on and off states of pins. Ones and zeros.

The Batronix looks good but, in addition to the price of the product, they want $60 to ship it. Approaching $300 for their basic EPROM programmer. Anything similar made in the states?

Thank you.

The vendor claims that the cartridges are unopened. Appears to be very nice lot. http://tinyurl.com/7qvse2c

I am interested in adding a two syllable spoken word to the intro page in my game. My inspiration is from Quadrun. First time I have heard speech Synthesis on the Atari 2600 VCS! Pretty cool. Couple of questions. Is the voice truly sythesized or is it a sample playback? If sampled, how many bytes does the playback routine code and sample data require? Thank you, JDR

Great article.

Seemed to worked just fine. For someone like me that has been exclusively in the Windows environment for last 15 years and not used to command line assembly this could be helpful. Just out of curiosity; why did you choose z26 over Stella as the emulator? Is Z26 more true to the VCS console?

Did you notice that eBay's stock description for the Atari VCS 2600 contains a serious error? They list the RAM as being 128KB. Don't we wish! (I guess the description writer couldn't wrap his brain around the concept of only 128 bytes.) --- JDR, wishing everyone a healthy and prosperous New Year.

I like the gameplay and the initial speed. Entertaining. The player slows down a bit much when the last trashcan is grabbed. I find it difficult to impossible to avoid the red dot. Scoring sometimes blocks out. Also would like to see the green playfield at least a line or two from the top. Keep at it. Looks promising.

Thank you! Great information.

Is there an "easter egg" or command that lets you display the values on demand in decimal, binary and hexidecimal? Not used to using decimal values.

Handy utility. Well done.

Excellent explanation. I understand "mirrored" addresses now. Thank you.

Very nice game! Thanks for posting. I used Stella to run it. The mouse control is a little iffy. Any DIY ideas on how to use a regular Atari joystick through the USB port so Stella can recognize it?

Thanks for the answers. The Harmony cartridge seems to be a very efficient way to test binaries quickly on the actual hardware. Thanks for that tip. +++ "Avoid deviating from the standard number of scanlines, that is 262 for NTSC and 312 for PAL." That's succinct. That helps in easing my mind regarding various TVs. I'll be programming for NTSC. +++ "Reset vector is at $1FFC (aka $FFFC)". Is that an example of a mirrored address? Or are you saying that the reset vector at $1FFC is pointing to $FFFC? (Sorry. Mirrored addresses are a new concept for me. Must have something to do with the way the 6507 addresses are mapped with only 13 pins.) +++ "You mean kernels? It's usually best to write them from scratch IMO." Sorry. Yes. Kernals. Thank you for the correct terminology.

Hello, I've recently become unemployed and have found myself without much money but with plenty of time. Been spending some of that time in thrift shops and discovered the 2600 in the form of a "Flashback 2" console. Way back in the day I did not have an Atari VCS 2600 system but many of my friends did. I recalled not being impressed with the machine at all. Especially after playing the uprights in arcades. The games on the VCS had terrible sound, Pacman flickered like mad and the graphics were blocky. Haven't given the system much thought in 33 years. After discovering the "Flashback 2" and titles like Missile Command, Saboteur, Pitfall and Quadrun I am willing to give this little system a second chance. Properly programmed it is quite capable of producing good sound and graphics. And more importantly, good fun! Since learning how the hardware is so limited I am even more impressed with the games: only 128 bytes of RAM, 4K of ROM, no OS/kernal graphics firmware, no video RAM, primitive drawing hardware, software must be raster timed, etc. My experience is programing the C64 and Atari 1040ST. The 2600 seems to be quite challenging. Looking forward to writing code for this machine. I guess I will use DASM as it has headers specifically for the 2600. Kind of wild though. Been a long time since I used any command line operated software. Just getting DASM running will be a bit of a challenge for me. LOL! I've read all the tutorials and documents I can find on programming the 2600 but I have a few questions that I could not find answers to: * I am guessing the 128 bytes of RAM are mapped in Zero Page. What addressed RAM locations are available to the programmer? * Is there enough room to write useful rewriteable code? * When turned on will the 6507 sometimes randomly be in BCD mode? Should I always do a CLD to make sure it is in binary mode? * Is the reset button a hard or soft reset? Does the hardware do a hard reset right after power up? * What are "mirrored" addresses in the 2600 memory map? How are they used? * Does DASM support undocumented, but often used, opcodes? * On a stock VCS and 4K cartridge what is the address of the first opcode to be run on power up? I am guessing $E000. * The VCS was introduced when all TVs were Cathode Ray Tube based. Any modification to code/timing needed to be made for modern TVs with LCD, Plasma, LED, etc. displays? * What make and model of PROM do you recommend for cartridges? * How do you get the binary code from the PC to the 2600 for testing? PROM burner each time or perhaps some type of DIY serial device? * Does anyone manufacture the handled cartridge cases, ala Air Raid, Enduro, anymore? Those are SO cool. * Any public domain graphic driver subroutines that handle drawing and raster timing efficiently? Best to write them from scratch for the specific game? * How much should a used 2600 VCS console sell for? Is it better to get the 7800? Any caveats to look out for when shopping for one? Thank you. --- JDR