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I've updated examples.zip with the three new formats. As I already explained to JAC!, HR2 is one of the formats supported by Lepix. Ripek's email is in FAIL's README.

http://xasm.atari.org

Cool picture, but I'd prefer schematics.

AFAIK CMOS 65xx have single write cycle in read-modify-write instructions.

Any news?

Aren't you aware of online version of Energy which was released last week? The original ATRs are there, too.

phaeron: did you get my email I sent you last week?

I'd say last 3, so there are 7 colors.

The VSCROL trick (a.k.a. "9++/10++ mode") should work on POKEY timer IRQ. You just need to setup the POKEY timer very precisely. Better use $FFFE because of ROM IRQ routine overhead. Whether your IRQ routine needs STA WSYNC probably depends on presence of rare 7-cycle instructions in the main thread because IIRC you have 6-cycle window to do the VSCROL store. In any case, you should gain some cycles compared to DLI, at the cost of an allocated POKEY channel and your time spent to make it work. Cycle-exact POKEY interrupts have been on Atari800 emulator's TODO list since its creation. Also: checkout source code of Numen for a simpler DLI routine which doesn't need a variable and runs every 8 scanlines instead of 4.

This should be: lda 20 cmp 20 beq *-2 If the OS or the VBLKI interrupt is disabled, you can use: lda $d40b bmi *-3 lda $d40b bpl *-3

Faster, one byte shorter and not using X: sec rol @ sta bin lda #0 sed do_bit sta bcd adc bcd asl bin bne do_bit cld

12 years ago I've seen a program which could display this mode with interlace, so that one frame was RGBRGB..., next one GBRGBR... and next one BRGBRG... This program wasn't new at that time (I think it was made in late 80's). It could optionally use GR.15 instead of GR.9 for increased resolution at the cost of lower color depth. It generally looked much worse than APAC because of more flickering and less saturation (even on a TV). Unfortunately I can't remember the name of this program.

I've just implemented two-tone mode emulation in ASAP. It emulates SKCTL bits 3 and 7. Here is the recording from the new ASAP emulation: http://asap.sourceforge.net/dm2-asap.mp3

So it's simply 2-tone mode normally used for cassette recordings. Its schema is drawn in pokeydoc. What I still wonder is whether it's useful for normal music?

What do you mean by 2-tone-filter? 2-tone mode used for cassette recording? If so, I can add emulation of it in ASAP. Do you have any examples of it being useful for music?

Please consider that a 3D game doesn't have to be a shooter with a high frame rate. I did not release these files. They were compiled by someone from Numen sources (it's as easy as typing one "make" command once you have all tools installed). Actually there are more keys that work, for example: J - toggles jet pack (fly with A and Z) Space - open/close doors and use elevators 1-3 - choose a weapon (there aren't guns in Numen, but the code supports them) He still has the option to make a very good 3D game and take part at the yearly ABBUC Software contest. So he has the chance to win 500€ ( ~ 700 $ ) 500€ for a very good 3D game for Atari is completely nothing compared to the fun factor.

TXA/PHA pair takes 5 cycles, PLA/TAX pair takes 6 cycles. Another alternative is saving registers on page zero - it takes 3 cycles to save and 3 to restore.

Actually you might have used an older version, because this one is only six weeks old.

I have an idea of extending the SAP file format with new tags, so more information can be included in the file. I do not like the idea of storing the extra information in a separate STIL.txt file, because it requires extra configuration of players. The COVER tag is an equivalent of STIL's TITLE and ARTIST tags. The title is wrapped in double quotes and the artist (if known) is specified after "by". If the song is a cover of a cover, multiple COVER tags can be specified: COVER "Ghostbusters" by Roger Duijckaerts (ReD) COVER "Ghostbusters [from the movie]" by Ray Parker, Jr. COMMENT tag is any command wrapped in double quotes and specified in one line with a limit of 1024 characters or so. AUTHORSCOMMENT is a comment written by the music author. Does anyone have an idea of a shorter name? COMPO specifies the competition the song started in. GAME, DEMO and ZINE specify titles of productions the song was used in. If the name of the production is already specified in NAME, the argument can be omitted. SONG specifies that the following information applies to the specified zero-based subsong. What do you think?

I guess Miker meant "useful".

The "profile" command isn't very useful. It just shows which opcodes are used most frequently. In 2001 I wrote a real profiler for xasm and the emulator. Basically the emulator counted how many times instruction at a given address is executed and how many cycles it takes. You could run your code for a while and dump the result to a file. Then there was a Java viewer that displayed histograms (horizontal axis = memory address, vertical axis = cycles taken) and had a zoom function. There was also another program that took a xasm listing with function boundaries marked with the "| PROFILE" comment and printed percentage of time spent by the 6502 in each function. You can probably find such comments in source code of Numen's portal engine. The tools were just prototypes so I'm not going to publish them.

Atari800 2.0.2 is quite different from 1.3.6 the current "PLus" bases on, but most changes do not impact the Windows version at all, because they are about portability, character-mode user interface, monitor enhancements (already included in PLus), code cleanup and such. The debugger generally introduces much more overhead than the cycle-exact emulation. I believe this overhead can be greatly reduced in the next version.

GBA is simply not powerful enough to emulate these machines. I've read about a 2600 emulator for GBA with hand-optimized assembly code and the author wrote that there are serious problems with getting 100% speed of the 2600 and a decent framerate.

Intro It is a demonstration program that has a limited length. You should include the length when you say "intro", because 256-byte intros are very different from 64 KB intros. Popular intro limits in Atari 8-bit world are: 256 bytes, 1 KB and 16 KB. In PC world these are: 256 bytes, 4 KB and 64 KB. 256-byte intros have usually one effect and no sound. Well-written 16 KB or 64 KB intros can be indistinguishable from demos when you are watching them (see "dentro"). Demo Demo competitions sometimes have length limits, but these are high. For example, Atari 8-bit demos could be limited to 4 * 130 KB and PC demos to 16 MB (I'm not sure about the present limits). It is questionable whether an intro is a demo or not. When you say "Yesterday I was watching PC demos" you probably mean that you watched demoscene productions, including intros. On the other hand intros usually aren't shown in "Demo compo", except for when there are few full-length demo entries. Megademo Megademo is a demo that consists of distinguishable parts. Megademo parts have different soundtracks, different effects and often are made by different people. Also, often there's a visible loader so you have to wait for the next part to load. Trackmo Trackmo is a demo which runs continuously without breaks for loaders or rapid soundtrack changes. The design should be consistent and effect changes should be smooth. Megademos are considered "old-school" while all modern demos are usually trackmos. Dentro The term "Dentro" is used rarely and applies to "big" intros (64 KB usually) that look like trackmos.

Ah, yes, that's too much of course. ".cas" images are meant to contain the exact digital contents of tapes. As Kr0tki mentioned, the Atari OS really writes 132 bytes per record: two sync bytes (0x55), one byte of block type (whether it's the last block of file, etc.), 128 bytes of data and a byte of checksum. This is what is stored in ".cas" files, with headers naturally. I meant specific revisions specified by the user. I booted an ATR with a DOS, entered the monitor and saw the loading address of $0880 (a sector buffer of the DOS, as expected).