From 47fa7a393cebb562a80dc6c3779c80df2854e3bb Mon Sep 17 00:00:00 2001
From: Rikard Nordgren <hrn@posteo.net>
Date: Mon, 17 Mar 2025 20:59:44 +0100
Subject: [PATCH] Add STRVAL

---
 STATUS.md                                    |  2 +-
 src/basic/,stubs_math/b7b5.STRVAL.s          | 20 --------
 src/basic/math/b7b5.STRVAL.s                 | 53 ++++++++++++++++++++
 src/basic/{,stubs_math => math}/b7b5.interop |  0
 strings/18608100000000                       |  3 ++
 strings/208CB64C                             |  3 ++
 strings/85248425                             |  3 ++
 testsuite/unit/math.vs                       | 12 +++++
 8 files changed, 75 insertions(+), 21 deletions(-)
 delete mode 100644 src/basic/,stubs_math/b7b5.STRVAL.s
 create mode 100644 src/basic/math/b7b5.STRVAL.s
 rename src/basic/{,stubs_math => math}/b7b5.interop (100%)
 create mode 100644 strings/18608100000000
 create mode 100644 strings/208CB64C
 create mode 100644 strings/85248425

diff --git a/STATUS.md b/STATUS.md
index 7d0716b9..422b7e4c 100644
--- a/STATUS.md
+++ b/STATUS.md
@@ -202,7 +202,7 @@ Floating point mathematical routines - not official, but well known and broadly
 | `$B391`   | `GIVAYF`               | PARTIAL  | not fully tested yet                               |
 | `$B3A2`   | `convert_Y_to_FAC1`    | DONE     |                                                    |
 | `$B794`   | `convert_u8_A_to_FAC1` | DONE     |                                                    |
-| `$B7B5`   | `STRVAL`               | NOT DONE | imports string to FAC1                             |
+| `$B7B5`   | `STRVAL`               | PARTIAL  | Only for 38k memory model                          |
 | `$B7F7`   | `convert_FAC1_to_ADDR` | NOT DONE |                                                    |
 | `$B849`   | `add_HALF_FAC1`        | DONE     |                                                    |
 | `$B850`   | `sub_MEM_FAC1`         | DONE     |                                                    |
diff --git a/src/basic/,stubs_math/b7b5.STRVAL.s b/src/basic/,stubs_math/b7b5.STRVAL.s
deleted file mode 100644
index 69acf4cc..00000000
--- a/src/basic/,stubs_math/b7b5.STRVAL.s
+++ /dev/null
@@ -1,20 +0,0 @@
-;; #LAYOUT# STD *       #TAKE
-;; #LAYOUT# X16 BASIC_0 #TAKE-OFFSET 2000
-;; #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
diff --git a/src/basic/math/b7b5.STRVAL.s b/src/basic/math/b7b5.STRVAL.s
new file mode 100644
index 00000000..49ebe76c
--- /dev/null
+++ b/src/basic/math/b7b5.STRVAL.s
@@ -0,0 +1,53 @@
+;; #LAYOUT# STD *       #TAKE
+;; #LAYOUT# X16 BASIC_0 #TAKE-OFFSET 2000
+;; #LAYOUT# *   BASIC_0 #TAKE
+;; #LAYOUT# *   *       #IGNORE
+
+;
+; Math package - converts string to FAC1
+;
+; 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
+; - https://www.c64-wiki.com/wiki/STRVAL
+;
+
+!ifdef CONFIG_MEMORY_MODEL_38K {
+; Only supported model for now since needs CHRGOT and FIN
+
+STRVAL:
+
+    ldx TXTPTR          ; Save TXTPTR
+    stx FBUFPT
+    ldx TXTPTR+1
+    stx FBUFPT+1
+
+    ldx INDEX           ; Move string address into TXTPTR
+    stx TXTPTR
+    ldx INDEX+1
+    stx TXTPTR+1
+ 
+    pha                 ; Save string length
+    tay
+    lda (INDEX),Y
+    sta TEMPF1          ; Save byte after string
+    lda #0
+    sta (INDEX),Y       ; NULL terminate string
+
+    jsr CHRGOT
+    jsr FIN
+ 
+    pla                 ; Retrieve string length
+    tay
+    lda TEMPF1
+    sta (INDEX),Y       ; Restore byte after string
+ 
+    ldx FBUFPT          ; Restore TXTPTR
+    stx TXTPTR
+    ldx FBUFPT+1
+    stx TXTPTR+1
+    rts
+}
diff --git a/src/basic/,stubs_math/b7b5.interop b/src/basic/math/b7b5.interop
similarity index 100%
rename from src/basic/,stubs_math/b7b5.interop
rename to src/basic/math/b7b5.interop
diff --git a/strings/18608100000000 b/strings/18608100000000
new file mode 100644
index 00000000..a7d8683d
--- /dev/null
+++ b/strings/18608100000000
@@ -0,0 +1,3 @@
+18 60 81 00 00 00 00
+
+CLC + RTS + Floating point number 1.0
diff --git a/strings/208CB64C b/strings/208CB64C
new file mode 100644
index 00000000..1a314d5f
--- /dev/null
+++ b/strings/208CB64C
@@ -0,0 +1,3 @@
+JSR $B68C + JMP fragment
+
+Call some place in ROM + jump fragment
diff --git a/strings/85248425 b/strings/85248425
new file mode 100644
index 00000000..872787af
--- /dev/null
+++ b/strings/85248425
@@ -0,0 +1,3 @@
+STA $24 + STY $25
+
+Store YA to well known zero page vector
diff --git a/testsuite/unit/math.vs b/testsuite/unit/math.vs
index 7f14b74e..410aa3cb 100644
--- a/testsuite/unit/math.vs
+++ b/testsuite/unit/math.vs
@@ -530,5 +530,17 @@ print "COMPARE"
 compare $61 $66 $1001
 print "END"
 
+print "TEST: STRVAL 200E-1"
+fill $61 $66 FF FF FF FF FF CC
+fill $22 $23 $00 $05
+fill $500 $507 32 30 30 45 2D 31 31
+r A=6
+r PC=$B7B5
+ret
+fill $1001 $1006 88 C8 00 00 00 00
+print "COMPARE"
+compare $61 $61 $1001
+print "END"
+
 
 q