Rule of Thumb (SN76489, SnoozeTracker)

[@4ofFive]

just realized the percussion at the start was actually dankpods destroying some buds with Scarlet Fire

[@srb2er]

i am now in love with yet another chiptune song why!!!11!1!!!1!!!!!

[@LunaOfTheStarsMusic]

You’ve seen rule of thumb Now get ready for, kid named finger

[@squarewave]

PKCELL-style. Funky af like usual, never give up!! :D

[@Evolution_BR811]

Sounds a lot like the Commodore 64

[@WindedCone]

P K C E L L P A R T Y

[@unyu-cyberstorm64]

If I could give your music *more than one* like per soing, I would.

[@pyra9345]

soing

[@unyu-cyberstorm64]

Very Nice

[@zaxolotl]

Is that Dankpods I hear at the beginning??? So awesome

[@dycedargselderbrother5353]

Has a Thomas Petersen/Laxity vibe to it.

[@TheEssem]

this is probably my favorite tune of yours now, nice job

[@Furmilion]

Woah, sure this is a nice song, it could perfectly fit as game's boss theme

[@nic0vide0]

“Oh, what a nugget this thing is!” (DankPods, 2023)

[@64Abstract]

better dub this genre now as pkcore

[@bl4z3pupz]

WAS THAT DANKPODS!?!?

[@eropzapolza]

omg amiga 8-bit

[@deadlyseed]

Bro speaking simolean

[@JFOX_6502]

OOOOOOOOOMG

[@dumbut]

sn76489 has samples?!?!?

[@NovaDXX]

Yes

[@stgigamovement]

The SN7 and AY series of chips (including clones) have a helpful bug in them in which if you change the volume while nothing is playing, the volume value will be outputted directly. So you can send samples as changes in the volume register at the cost of heavy CPU usage. On the SN7 and AY series, the volume register is 4 bits. Also it's worth mentioning that the AY series of chips has an internal volume envelope feature that doesn't require a sound to be played, AND can be set to a high enough frequency to get into the human audio range. Thus the AY series of chips accidentally can produce triangle and saw waves as well as tripulse and sawpulse waves with far less CPU use than you would need on SnoozeTracker. Both the designs of the SN7 and AY series originate in 1979. A year in which pretty much the only sampler synth in music was the ridiculously expensive Fairlight CMI. Meanwhile, the PSG chips of that era made by Texas Instruments and General Instrument support arbitrary PCM over the volume register. The CMI was 8 bit, and if you stringed multiple PCM channels together for one signal you can get 8bit output. Also, the 1979 Atari PoKEY and the 1977 Atari TIA are also the recipients of being able to play PCM over their volume register. So these late 1970s chip designs all have bugs in them and their clones that allows PCM playback over the volume register. The chips weren't intended to be usable as DACs, but nonetheless they can be used as DACs. This type of trick was known back in the day. Several games on various platforms with such chips tended to use this feature for speech in moments where CPU time and the task at hand wouldn't be destroyed by using the CPU to play brief samples. The C64 Ghostbusters voice sample is also played via this same type of trick on the C64 which has a similar bug. Pitfall 2 on the Atari 2600 uses a chip in the cartridge to generate 3 square waves and mix them down to a single 4bit signal that the game then writes to channel 1's volume register whenever spare CPU cycles are available. Many Commodore 64 games had stuff like percussion (which best survives being 4bit) played back on the older C64 SID's volume register. Before the OPNA/YM2608, people on the Japanese PC98 would use the volume register PCM trick on the AY-3-8910 clone that resides in the PC98 OPN series of Yamaha FM sound chips apart from the YM2612 in the Genesis. Even after the OPNA, some games still sent samples over the volume register to remain compatible with machines still using the original OPN. This trick works on ALL clones. The YMF297 (the OPN4, which is a hybrid of the low voltage OPL3 and OPN3, in the chip package of a low-voltage OPL3, and was made for late 90s PC98 machines that ran Windows) in its OPN3 mode (you have to toggle between OPN3 and OPL3 modes. You can't have OPL3 and OPN3 at once in a YMF297 because Yamaha was silly) still has the internal AY-3-8910 clone which still has the ability to be used as a DAC. For context, the OPN3 and OPN4 don't have the non-drum PCM of the OPNA. Also if using a YM2610B, which has 6 FM channels (the YM2610 of the Neo Geo has two permanently blanked so it wouldn't outfox the original OPN) and 7 PCM channels and 3 PSG channels, if you use the PCM trick on its internal AY-3-8910 clone, you end up with 6 FM channels and ten sample channels. The YM2610B was used in arcade machines, so ultimately they could have actually had the CPU to spare if using a sound processor (not uncommon in arcades) to have the full ten PCM channels the chip can do without impacting gameplay. Even the newest Neo Geo units (the Neo Geo had a very long life) still can do PCM out of the internal AY-3-8910 clones in their YM2610s, and even the brand new Sega Master Systems still made for the Brazilian market to this day still support the PCM trick on their PSGs that are clones of the SN7. So these late 1970s design quirks of the SN7, AY series chips, and the Atari 2600 TIA still exist today despite being completely accidental. An accident that allows samples on machines with far worse specs than the pioneer-of-samplers Fairlight CMI of 1979. The TIA in fact pre-dates the CMI by two years. Also if one uses pulse frequency modulation, technically you can get samples out of the 1976 Fairchild Channel F.

[@SolidEyeYEG]

Amazing, wrangling the SN7 like this

[@stgigamovement]

@@gameborge SnoozeTracker uses this trick

[@stgigamovement]

@@gameborge you're welcome!

[@hacktrixapii]

The iPod man! Really?

[@pschiptunes64]

Let me just get one of my AAAEEHs

[@Sian37]

PKCELLS STYLE BOIIII!

[@Ravalo354]

oh my pkcell..

[@Antiblue643]

what does dankpods say at the beginning?

[@RoshwyinsTaicoon]

"Get down on some PKCELLS, That's what I wanna know!" I think.

[@dvdvideo5013]

Sega Master System PCM

[@Flo_Resolution]

Noice

[@GGVIC25]

Z80?

[@FLDE]

Works better on a 68k

[@dycedargselderbrother5353]

@@FLDE This that the case? That Snoozetracker's reference CPU is a 68K rather than Z80?

[@sleeping_lugia]

@@FLDE Atari ST with SN76489, now selling at stores at only 799.99 dollars, 999.99 with a color monitor!

[@FLDE]

@@dycedargselderbrother5353 it’s actual SN7 register writes. Any CPU can write them, but a 68k would have an easier job

[@dycedargselderbrother5353]

​@@FLDE I get it now. Somehow I thought Snoozetracker was written against a reference, a z80 in particular. Now the criticisms of it being unrealistic make more sense.

[@misty_fogT-T]

owo