(Partially) K007232 support

Chip ID is placeholder.

papers/doc/6-sample/README.md

@@ -25,6 +25,7 @@ as of Furnace 0.6, the following sound chips have sample support:
 - tildearrow Sound Unit
 - VERA (last channel only)
 - Y8950 (last channel only)
+- Konami K007232
 - a few more that I've forgotten to mention
 
 ## compatible sample mode

papers/doc/7-systems/README.md

@@ -12,6 +12,7 @@ this is a list of sound chips that Furnace supports, including effects.
 - [Generic PCM DAC](dac.md)
 - [Famicom Disk System](fds.md)
 - [Game Boy](game-boy.md)
+- [Konami K007232](k007232.md)
 - [Konami SCC](scc.md)
 - [Konami VRC6](vrc6.md)
 - [Atari Lynx](lynx.md)

papers/doc/7-systems/k007232.md

@@ -0,0 +1,9 @@
+# Konami K007232
+
+a Konami's 2 channel PCM sound chip was used in their arcade boards in 1986-1990.
+
+Its sample format is unique; the topmost bit is the end marker, and the low 7 bits are used for generating sound (unsigned format).
+
+# effects
+
+- Nothing for now