implemented NORMAL math routine, added more stubs

STATUS.md

@@ -177,13 +177,14 @@ Floating point mathematical routines - not official, but well known and broadly
 | Address   | Name         | Status   |  Remarks                                           |
 | :-------: | :----------- | :------: | :------------------------------------------------: |
 | `$B1AA`   | `FACINX`     | NOT DONE | convert FAC1 to 16-bit signed integer              |
-| `$B391`   | `GIVAYF`     | NOT DONE | XXX - no stub added yet                            |
+| `$B391`   | `GIVAYF`     | NOT DONE | 16-bit signed integer to FAC1                      |
-| `$B7B5`   | `STRVAL`     | NOT DONE | XXX - no stub added yet                            |
+| `$B7B5`   | `STRVAL`     | NOT DONE | imports string to FAC1                             |
 | `$B850`   | `FSUB`       | PARTIAL  | needs `FSUBT`                                      |
 | `$B853`   | `FSUBT`      | NOT DONE | subtract FAC1 from FAC2                            |
 | `$B867`   | `FADD`       | PARTIAL  | needs `FADDT`                                      |
 | `$B86A`   | `FADDT`      | NOT DONE | add FAC2 to FAC1                                   |
-| `$B9EA`   | `LOG`        | NOT DONE | XXX - no stub added yet                            |
+| `$B8FE`   | `NORMAL`     | PARTIAL  | not tested yet                                     |
+| `$B9EA`   | `LOG`        | NOT DONE | natural logarigthm                                 |
 | `$BA28`   | `FMUL`       | PARTIAL  | needs `FMULT`                                      |
 | `$BA2B`   | `FMULT`      | NOT DONE | multiplies FAC1 by FAC2                            |
 | `$BA8C`   | `CONUPK`     | PARTIAL  | not fully tested yet                               |
@@ -196,24 +197,25 @@ Floating point mathematical routines - not official, but well known and broadly
 | `$BBFC`   | `MOVEF`      | NOT DONE | copy FAC2 to FAC1                                  |
 | `$BC0F`   | `MOVFA`      | NOT DONE | copy FAC1 to FAC2, skips rounding                  |
 | `$BC2B`   | `SIGN`       | NOT DONE | evaluate FAC1 sign                                 |
-| `$BC39`   | `SGN`        | NOT DONE | XXX - no stub added yet                            |
+| `$BC39`   | `SGN`        | NOT DONE | evaluate FAC1 sign, to FAC1                        |
-| `$BC58`   | `ABS`        | NOT DONE | XXX - no stub added yet                            |
+| `$BC58`   | `ABS`        | NOT DONE | absolute value                                     |
 | `$BC5B`   | `FCOMP`      | NOT DONE | compare FAC1 with RAM location                     |
-| `$BC9B`   | `QINT`       | NOT DONE | XXX - no stub added yet                            |
+| `$BC9B`   | `QINT`       | NOT DONE | convert FAC1 to 32 bit signed integer              |
-| `$BCCC`   | `INT`        | NOT DONE | XXX - no stub added yet                            |
+| `$BCCC`   | `INT`        | NOT DONE | rounds away the decimal to make an integer         |
-| `$BCF3`   | `FIN`        | NOT DONE | XXX - no stub added yet                            |
+| `$BCF3`   | `FIN`        | NOT DONE | imports string to FAC1, ignores spaces             |
-| `$BDDD`   | `FOUT`       | NOT DONE | XXX - no stub added yet                            |
+| `$BDDD`   | `FOUT`       | NOT DONE | outputs FAC1 to string at $0100                    |
-| `$BF71`   | `SQR`        | NOT DONE | XXX - no stub added yet                            |
+| `$BF71`   | `SQR`        | NOT DONE | square root of FAC1                                |
+| `$BF74`   | `SQR2`       | NOT DONE | square root of FAC2                                |
 | `$BF78`   | `FPWR`       | NOT DONE | set FAC1 as RAM raised to the power of FAC1        |
 | `$BF7B`   | `FPWRT`      | NOT DONE | set FAC1 as FAC2 raised to the power of FAC1       |
 | `$BFB4`   | `NEGOP`      | DONE     |                                                    |
-| `$BFED`   | `EXP`        | NOT DONE | XXX - no stub added yet                            |
+| `$BFED`   | `EXP`        | NOT DONE | exponential function, e raised to FAC1 power       |
 | `$E043`   | `POLY1`      | NOT DONE | evaluate polynomial with odd powers only           |
 | `$E059`   | `POLY2`      | NOT DONE | evaluate polynomial with odd and even powers       |
 | `$E264`   | `COS`        | NOT DONE | cosine of FAC1 in radians                          |
 | `$E26B`   | `SIN`        | NOT DONE | sine of FAC1 in radians                            |
 | `$E2B4`   | `TAN`        | NOT DONE | tangent of FAC1 in radians                         |
-| `$E30E`   | `ATN`        | NOT DONE | XXX - no stub added yet                            |
+| `$E30E`   | `ATN`        | NOT DONE | arc tangent of FAC1                                |
 
 <br />
 

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