- AtariTufty
- Beepinator
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- utz
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Re: Dubstep generator
Sounds surprisingly nice for being so simple.
start
ld b,1
ld hl,#4000
loop
ld a,(hl)
add a,b
ld b,a
ld (hl),a
out (#fe),a
inc hl
ld a,h
cp #58
jp nz,loop
jp startCould've easily shaved at least 3 bytes off, though 
I still would like to see a bytebeat interpreter for beeper one day. Or rather, bitbeat... I don't see how it could be done though, considering the thing needs to run in constant time.
Re: Dubstep generator
like this one?
http://www.pouet.net/prod.php?which=87664
- utz
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Re: Dubstep generator
Ah, yes, Serzhsoft delivers, as usual. Thanks for reminding me about that one, I forgot to check that out when it was released!
5 2021-01-08 16:40:12 (edited by cborn 2021-01-08 16:41:31)
Re: Dubstep generator
SherzhSoft s version is close to it
and can be shorter as well ??
;http://www.pouet.net/prod.php?which=87664
;digital opera in 22-2 bytes
;Serzhsoft, 2 bytes removed by cborn
start:
ad00 di
ad01 ld e,c ; c from basic call = start adres
ad02 ld hl,0x5800
ad05 ld b,h
ad06 ld a,(bc)
ad07 ld e,a
ad08 add a,e
ad09 inc bc
ad0a dec hl
ad0b cpl
ad0c out (0xfe),a
ad0e sub (hl)
ad0f ld (hl),a
ad10 cp (hl)
ad11 jr z,ad05
ad13 inc e ; 'e' will be overwritten and this 'inc' can be removed, OR the loop has to be re-rwritten so it will be increased..... a puzzle!!
ad14 jr ad02
oops sudden rewrite?
in lower memory its funky!!
;http://www.pouet.net/prod.php?which=87664
;digital opera in 22 bytes
;Serzhsoft
start:
ad00 di
ad01 ld e,c ; c from basic call = start adres
ad02 ld hl,0x5800
ad05 ld b,h
ad06 ld a,(bc)
ad08 add a,a
ad09 inc bc
ad0a dec hl
ad0b cpl
ad0c out (0xfe),a
ad0e sub (hl)
ad0f ld (hl),a
ad10 cp (hl)
ad11 jr z,ad05
ad14 jr ad02
6 2021-01-08 16:48:02 (edited by Shiru 2021-01-09 17:43:08)
Re: Dubstep generator
Great stuff!
As I understand, the amount of bits involved into an LFSR directly affects to the length of evolutions of the sound in time, while bits change density per second (like, how fast LFSR is counting) affects to the richness of the harmonic content. So here we have 6144*8 bits large LFSR, even though these bits may be used not the most efficient way. Overall it is just like a regular LFSR-based noise generator like in all old sound chips, but with tricky looped sub-periods (noise harmonics?) in it.
- utz
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Re: Dubstep generator
I've been wondering for some time if there is a way of replacing the usual 16-bit frequency counters with an LFSR or something of that sort. Feels like such a waste to spend 4 registers on a simple counter every time.