implemented NORMAL math routine, added more stubs

c64/basic/,stubs_math/b391.GIVAYF.s

@@ -0,0 +1,20 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Math package - 16-bit signed integer to FAC1
+//
+// Output:
+// - .A - address high byte (XXX really, not the opposite?)
+// - .Y - address low byte
+//
+// See also:
+// - [CM64] Computes Mapping the Commodore 64 - page 107
+// - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
+//
+
+// XXX provide implementation
+
+GIVAYF:
+	STUB_IMPLEMENTATION()

c64/basic/,stubs_math/b391.interop

@@ -0,0 +1,3 @@
+This is an important floating point math routine, documented in many places.
+
+XXX - try to find real-life example

c64/basic/,stubs_math/b7b5.STRVAL.s

@@ -0,0 +1,19 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Math package - imports string to FAC1 - XXX: what about spaces?
+//
+// Input:
+// - .A needs to be loaded with string length
+// - string address in $22/$23
+//
+// See also:
+// - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
+//
+
+// XXX provide implementation
+
+STRVAL:
+	STUB_IMPLEMENTATION()

c64/basic/,stubs_math/b7b5.interop

@@ -0,0 +1,3 @@
+This is an important floating point math routine, documented in many places.
+
+XXX - try to find real-life example

c64/basic/,stubs_math/b9ea.LOG.s

@@ -0,0 +1,18 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Math package - natural logarigthm
+//
+//
+// See also:
+// - [CM64] Computes Mapping the Commodore 64 - page 113
+// - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
+// - https://codebase64.org/doku.php?id=base:kernal_floating_point_mathematics
+//
+
+// XXX provide implementation
+
+LOG:
+	STUB_IMPLEMENTATION()

c64/basic/,stubs_math/b9ea.interop

@@ -0,0 +1,3 @@
+This is an important floating point math routine, documented in many places.
+
+XXX - try to find real-life example

c64/basic/,stubs_math/bc2b.SIGN.s

@@ -3,10 +3,10 @@
 // #LAYOUT# *   *       #IGNORE
 
 //
-// Math package - evaluate FAC1 sign
+// Math package - evaluate FAC1 sign, to .A
 //
 // Output:
-// - .A - $00 for equal, $01 for FAC1 > RAM, $FF for FAC1 < RAM
+// - .A - 0 for FAC1 equal 0, 1 for FAC1 > 0, -1 for FAC1 < 0
 //
 // See also:
 // - [CM64] Computes Mapping the Commodore 64 - page 115

c64/basic/,stubs_math/bc39.SGN.s

@@ -0,0 +1,20 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Math package - evaluate FAC1 sign, to FAC1
+//
+// Output:
+// - FAC1 - 0 for FAC1 equal 0, 1 for FAC1 > 0, -1 for FAC1 < 0
+//
+// See also:
+// - [CM64] Computes Mapping the Commodore 64 - page 115
+// - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
+// - https://codebase64.org/doku.php?id=base:kernal_floating_point_mathematics
+//
+
+// XXX provide implementation
+
+SGN:
+	STUB_IMPLEMENTATION()

c64/basic/,stubs_math/bc39.interop

@@ -0,0 +1,3 @@
+This is an important floating point math routine, documented in many places.
+
+XXX - try to find real-life example

c64/basic/,stubs_math/bc58.ABS.s

@@ -0,0 +1,17 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Math package - absolute value
+//
+// See also:
+// - [CM64] Computes Mapping the Commodore 64 - page 115
+// - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
+// - https://codebase64.org/doku.php?id=base:kernal_floating_point_mathematics
+//
+
+// XXX provide implementation
+
+ABS:
+	STUB_IMPLEMENTATION()

c64/basic/,stubs_math/bc58.interop

@@ -0,0 +1,3 @@
+This is an important floating point math routine, documented in many places.
+
+XXX - try to find real-life example

c64/basic/,stubs_math/bc9b.QINT.s

@@ -0,0 +1,19 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Math package - convert FAC1 to 32 bit signed integer
+//
+// Output:
+// - $62-$65, big-endian order
+//
+// See also:
+// - [CM64] Computes Mapping the Commodore 64 - page 115
+// - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
+//
+
+// XXX provide implementation
+
+QINT:
+	STUB_IMPLEMENTATION()

c64/basic/,stubs_math/bc9b.interop

@@ -0,0 +1,3 @@
+This is an important floating point math routine, documented in many places.
+
+XXX - try to find real-life example

c64/basic/,stubs_math/bccc.INT.s

@@ -0,0 +1,17 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Math package - rounds away the decimal to make an integer
+//
+// See also:
+// - [CM64] Computes Mapping the Commodore 64 - page 116
+// - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
+// - https://codebase64.org/doku.php?id=base:kernal_floating_point_mathematics
+//
+
+// XXX provide implementation
+
+INT:
+	STUB_IMPLEMENTATION()

c64/basic/,stubs_math/bccc.interop

@@ -0,0 +1,3 @@
+This is an important floating point math routine, documented in many places.
+
+XXX - try to find real-life example

c64/basic/,stubs_math/bcf3.FIN.s

@@ -0,0 +1,23 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Math package - imports string to FAC1, ignores spaces
+//
+//
+// Input:
+// - .A needs to be loaded with first char of the string
+// - Carry flag must be clear
+// - string address in $7A/$7B
+//
+// See also:
+// - [CM64] Computes Mapping the Commodore 64 - page 116
+// - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
+// - https://codebase64.org/doku.php?id=base:kernal_floating_point_mathematics
+//
+
+// XXX provide implementation
+
+FIN:
+	STUB_IMPLEMENTATION()

c64/basic/,stubs_math/bcf3.interop

@@ -0,0 +1,3 @@
+This is an important floating point math routine, documented in many places.
+
+XXX - try to find real-life example

c64/basic/,stubs_math/bddd.FOUT.s

@@ -0,0 +1,21 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Math package - outputs FAC1 to string at $0100
+//
+// Output:
+// - .A - address low byte
+// - .Y - address high byte
+//
+// See also:
+// - [CM64] Computes Mapping the Commodore 64 - page 116
+// - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
+// - https://codebase64.org/doku.php?id=base:kernal_floating_point_mathematics
+//
+
+// XXX provide implementation
+
+FOUT:
+	STUB_IMPLEMENTATION()

c64/basic/,stubs_math/bddd.interop

@@ -0,0 +1,3 @@
+This is an important floating point math routine, documented in many places.
+
+XXX - try to find real-life example

c64/basic/,stubs_math/bf71.SQR.s

@@ -0,0 +1,20 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Math package - square root of FAC1
+//
+// Note:
+// - transfers FAC1 to FAC2 and falls through to SQR2
+//
+// See also:
+// - [CM64] Computes Mapping the Commodore 64 - page 117
+// - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
+// - https://codebase64.org/doku.php?id=base:kernal_floating_point_mathematics
+//
+
+// XXX provide implementation
+
+SQR:
+	STUB_IMPLEMENTATION()

c64/basic/,stubs_math/bf71.interop

@@ -0,0 +1,3 @@
+This is an important floating point math routine, documented in many places.
+
+XXX - try to find real-life example

c64/basic/,stubs_math/bf74.SQR2.s

@@ -0,0 +1,20 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Math package - square root of FAC2
+//
+// Note:
+// - loads .5 into FAC1 and falling through to the exponentiation routine
+//
+// See also:
+// - [CM64] Computes Mapping the Commodore 64 - page 117
+// - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
+// - https://codebase64.org/doku.php?id=base:kernal_floating_point_mathematics
+//
+
+// XXX provide implementation
+
+SQR2:
+	STUB_IMPLEMENTATION()

c64/basic/,stubs_math/bf74.interop

@@ -0,0 +1,3 @@
+This is an important floating point math routine, documented in many places.
+
+XXX - try to find real-life example

c64/basic/,stubs_math/bfed.EXP.s

@@ -0,0 +1,18 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Math package - exponential function, e raised to FAC1 power
+//
+//
+// See also:
+// - [CM64] Computes Mapping the Commodore 64 - page 117
+// - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
+// - https://codebase64.org/doku.php?id=base:kernal_floating_point_mathematics
+//
+
+// XXX provide implementation
+
+EXP:
+	STUB_IMPLEMENTATION()

c64/basic/,stubs_math/bfed.interop

@@ -0,0 +1,3 @@
+This is an important floating point math routine, documented in many places.
+
+XXX - try to find real-life example

c64/basic/,stubs_math/e30e.ATN.s

@@ -0,0 +1,17 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Math package - arc tangent of FAC1
+//
+// See also:
+// - [CM64] Computes Mapping the Commodore 64 - page 211
+// - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
+// - https://codebase64.org/doku.php?id=base:kernal_floating_point_mathematics
+//
+
+// XXX provide implementation
+
+ATN:
+	STUB_IMPLEMENTATION()

c64/basic/,stubs_math/e30e.interop

@@ -0,0 +1,3 @@
+This is an important floating point math routine, documented in many places.
+
+XXX - try to find real-life example

c64/basic/math/NORMAL.s

@@ -0,0 +1,100 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Math package - normalize FAC1
+//
+// See also:
+// - [CM64] Computes Mapping the Commodore 64 - page 113
+// - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
+// - https://codebase64.org/doku.php?id=base:kernal_floating_point_mathematics
+//
+
+// XXX test this
+
+NORMAL:
+
+	lda FAC1_exponent
+	beq normal_end                     // branch if our float is 0
+	
+	lda FAC1_mantissa+3
+	beq normal_by_byte                 // branch if we can move the whole byte
+	
+	and #$80
+	bne normal_end                     // branch if already normalized
+	
+	// FALLTROUGH
+	
+normal_by_bit:
+	
+	// First check the current exponent
+	
+	lda FAC1_exponent
+	cmp #$01
+	bne !+
+	
+	// Exponent is 1 - just mark the whole number as 0 and finish
+	
+	lda #$00
+	sta FAC1_exponent
+	rts
+!:
+	// Multiply the mantissa by 2
+
+	clc
+	rol FACOV
+	rol FAC1_mantissa+0
+	rol FAC1_mantissa+1
+	rol FAC1_mantissa+2
+	rol FAC1_mantissa+3
+	
+	bcc NORMAL                         // branch if next iteration needed
+	rts
+	
+normal_by_byte:
+
+	// First decrement the exponent by 8, but not below 0
+	
+	lda FAC1_exponent
+	sec
+	sbc #$08
+	bcs !+
+	lda #$00
+!:
+	sta FAC1_exponent
+	beq normal_end                     // branch if our float reached 0
+
+	// Now multiply the mantissa by 8 by moving the whole bytes
+	
+	lda FAC1_mantissa+2
+	sta FAC1_mantissa+3
+	lda FAC1_mantissa+1
+	sta FAC1_mantissa+2
+	lda FAC1_mantissa+0
+	sta FAC1_mantissa+1
+	
+	lda FACOV
+	sta FAC1_mantissa+0
+
+	lda #$00
+	sta FACOV
+	
+	// Now check if mantissa is not 0
+	
+	ora FAC1_mantissa+0
+	ora FAC1_mantissa+1
+	ora FAC1_mantissa+2
+	ora FAC1_mantissa+3
+	
+	bne NORMAL                         // not 0 - branch to next iteration
+
+	// Our mantissa reached 0 - mark exponent as 0 and finish
+	
+	sta FAC1_exponent
+
+	// FALLTROUGH
+
+normal_end:
+
+	rts

c64/basic/math/b8fe.NORMAL.jmp.s

@@ -0,0 +1,7 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+// Just a compatibility jump - our routine is longer than original one
+
+	jmp NORMAL

c64/basic/math/b8fe.interop

@@ -0,0 +1,3 @@
+This is an important floating point math routine, documented in many places.
+
+XXX - try to find real-life example