From: Tobias Girstmair <tobi@isticktoit.net>
Date: Thu, 4 Mar 2021 21:38:26 +0000 (+0100)
Subject: new version
X-Git-Url: https://git.gir.st/Chiptunes-pms150c.git/commitdiff_plain/14ba6899f4b523e8c7efa3ac47c3e65a666c2870

new version

code borrowed from attiny version
---

diff --git a/bsv.c b/bsv.c
index 23f7a5e..367610e 100644
--- a/bsv.c
+++ b/bsv.c
@@ -56,8 +56,21 @@ void g(void){
 	SET1	(notes_ix, 3)		} // ix += 8 <=> ix |= 8
 	IDXM	(acc, notes+notes_ix)
 	u8 result = ((i1<<8|i0)*acc)>>8;  // keep hi byte
-	//^TODO!
-	acc = result;
+	//^TODO! https://git.gir.st/Chiptunes.git/blob/d397f89:/foo.c#l83
+	//final: https://git.gir.st/Chiptunes.git/blob/f8e0502:/foo.S#l113
+	u8 a2 = 0; // can probably be overloaded onto mul3lo/hi
+	u8 a1 = 0; // -"-
+	u8 t  = acc; // note input (as returned by idxm)
+	for (u8 loop = 0; loop < 8; loop++) {
+		if (t & 1) {
+			/*(2) ADDC a2, i1*/	a2 += i1 + ((a1+i0)>>8);
+			/*(1) ADD  a1, i0*/	a1 += i0;
+		}
+		/*(3) LSR t*/	t >>= 1;
+		/*(2) ROR a1*/	a1>>= 1;a1 |= a2<<7;
+		/*(1) LSR a2*/	a2>>= 1;
+	}
+	acc = a1;
 }
 void main(void){
 	CLEAR	(i0)