diff --git a/README.md b/README.md index 94f84c7..faf5988 100644 --- a/README.md +++ b/README.md @@ -12,7 +12,7 @@ * Manuals from Sam Coupe: https://velesoft.speccy.cz/samcoupe/saa1099/saa1099-doc5-en.png * Manuals from Sam Coupe: https://www.worldofsam.org/products/saa1099 -## Chip technical capabilitie +## Chip technical capabilities * 6 frequency generators, 8 octaves, 256 tones per octave, frequency range ffrom 31 Hz to 7.81 kHz * 2 noise generators, range from 61 to 15.6 kHz @@ -42,9 +42,24 @@ SAA1099 (Philips) CLK 8 11 D1 GND 9 10 D0 ``` + ## Tests * envelope test: https://www.youtube.com/watch?v=-ELEH-RX0JE -* + + +## Recordings from the real chip by Jepael +http://www.vogons.org/viewtopic.php?f=9&t=51695 + +### Noise +``` +SAA1099P noise generator as documented by Jepael +seed unknown, must be non-zero +18-bit Galois LFSR +Feedback polynomial = x^18 + x^11 + x^1 +Period = 2^18-1 = 262143 bits +Verified to match recorded noise from my SAA1099P +``` + ## Implementations * MAME https://github.com/mamedev/mame/blob/master/src/devices/sound/saa1099.cpp