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About Synthpopalooza

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    River Patroller

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  • Location
    knoxville, TN
  • Interests
    Atari and Amiga computers, Doctor Who, science fiction, 1980's electronic and new wave music

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  1. A short preview of Area 5 ice world theme from E.X.O. AUDCTL =$61 SKCTL=$8B 0 - $Ax saw wave modulation 1 - silent, frequency carrier 2 - $2x bell @1.79 3 - $Ax bass @15khz This is SKCTL two tone mode 1.79 + 15 khz. You get a nice high saw wave to use atop a deep $Ax square bass. Certain frequencies decrease the volume, I used this to put a delay echo effect in. Binary coming soon. exo-area5.wav
  2. I am still curious to see what you can do in 320B with Kangaroo mode. But yes, you guys should try to make a game. Even a port of Robbo would be great.
  3. On the above setting: I am going to attempt the famous Metroid title music in double POKEY, using the above SKCTL setting, which is perfect for those high pitched notes at the beginning.
  4. And then ... the E.X.O. title music: AUDCTL=$40 (1.79 mhz) SKCTL=$8B (two tone) 0 - $Ax frequency modulation 1 - $Ax - frequency carrier, lower volume 2 - $Cx bass (both RMT C and E) 3 - $Ax standard square wave In SKCTL two-tone 1.79, you get two note tables. One is the famous "Save to cassette" bell sound, and one is a higher pitched saw wave. By varying the frequency in channel 1, a volume slide/modulation effect can be had. This mode requires the standard 64khz clock, so you are forced to use standard $Cx for bass sounds and standard $Ax for any other musical tones. This is the title music for E.X.O., another original composition. The volume fade effect is used at the beginning, then the CSAVE bell comes in during the second part. Note table for this setting is available in my POKEY table on the 7800 Programming forum. exo-title.asm exo-title.s exo-title.xex
  5. So, more single POKEY experiments: I finally have a 98% documented note table for AUDCTL=$64 $2x distortion hi-pass with double 1.79 clock. AUDC0=$2x AUDC2=$00 AUDCTL=$64 v1.0.txt Here's how it works ... The first channel is the frequency carrier, and it takes values from my standard $2x @1.79mhz frequency table. The third channel is the modulation. Certain values will make a swirling guitar effect, while others make unpleasant noise. If (freq+4) mod 31=1 on the third channnel frequency, a solid tone is created. As this value goes down, the volume shifts down. This can be used to introduce echo effects into the music. If frequency in 3 = frequency in 0, a solid tone is also made. This is a very incomplete table. Other solid frequencies can be had. Anything with a * after it is the optimum swirling frequency for that note. Also included here is a sample piece: The Area 1 theme from an upcoming 7800 game called E.X.O. This is an original composition. Second channel is a $Cx bass while the fourth is a standard $Ax square wave, The table is very rough, and may have errors. Use at your own risk. exo-area1.s exo-area1.xex exo-area1.asm
  6. No. I had designed it to use $0x distortion (pink noise) but in PMP's code it accidentally got set to $Cx (saw wave) and made a buzz instead.
  7. Or that idiot on the Atari 8-bit forums who posted news about a Delorean racing game that'd use extra colors, then got butthurt about it when he got called on his bullshit and said he was stopping development on it because we were too mean to him, and instead work on an Amiga version. 😂😂😂
  8. Does the source still exist? I might try doing a POKEY soundtrack to it.
  9. Full title theme! Setup is: AUDCTL=$40 SKCTL=$8B (Two tone) 00 - $Ax @1.79 mhz ... frquency modulation 01 - silent ... carrier frequency 02 - $Cx ... bass (both mod 3 and non mod 3) 03 - $Ax ... standard square wave exo-title.wav
  10. The other modes (apart from the 4 color 160A and two color 320A) 320C ... is a 320 pixel mode, but has the limitation that every nybble must take its color from the same Px palette number. 320D ... is a weird one. Even columns are taken from one palette and odd columns from another. I did try an interlace experiment once where you swap character sets and also color palettes, to get a 320 pixel vertical line interlace, but it didn't look very well. So 320D is, at least to me, not of much use. DMA costs: 160A/320A has lower DMA overhead than 160B/320B. 320C DMA overhead matches to 320B, and 320D DMA overhead matches to 320A. This should be kept in mind when using these modes for actual in-game graphics.
  11. When you do 320B ... It works like Antic 4 on the XL/XE but with one caveat: 00 and 01 can't occupy the same nybble. It will result in both pixels being blank. There is a way to defeat this, by engaging what is called Kangaroo mode, by turning off transparency. The tradeoff for this is, 00 on your sprites will return the BG color, and not transparency. Also you get two palettes available instead of just one. Not usually used in game because of high DMA/MARIA costs, but can be used for static pictures/title screens.
  12. You should also try 320B. I did some experiments with interlacing that get about 70 colors in 160A, about 100 in 160B, and 20 in 320B. Its done by swapping charsets.
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