Add absolute store instructions sta/sta2

2 files changed, 27 insertions, 9 deletions

diff --git a/src/main.c b/src/main.c
index 33f53c3..8dbaf45 100644
--- a/src/main.c
+++ b/src/main.c
@@ -134,8 +134,10 @@ init_uxn() {
         // 0x80, 0xff, 0x80, 1, 0x13, 0xa0, 0xaa, 0xbb,
         // 0xa0, 0xff, 0xee, 0x80, 1, 0x33, 0xa0, 0xaa, 0xbb,
         // LDA /STA
-        0xa0, 0x01, 0x05, 0x14, 0xa0, 0xaa, 0xbb,
-        0xa0, 0x01, 0x05, 0x34, 0xa0, 0xcc, 0xdd,
+        // 0xa0, 0x01, 0x05, 0x14, 0xa0, 0xaa, 0xbb,
+        // 0xa0, 0x01, 0x05, 0x34, 0xa0, 0xcc, 0xdd,
+        0xa0, 0xab, 0xcd, 0xa0, 0x01, 0x08, 0x15,
+        // 0xa0, 0xab, 0xcd, 0xa0, 0x01, 0x08, 0x35,
     };
     memcpy(uxn_ram + PAGE_PROGRAM, uxn_rom, sizeof(uxn_rom));
 }
@@ -143,7 +145,6 @@ init_uxn() {
 // TODO:
 //  - Division
 //  - DEI/DEO
-//  - Absolute load/store
 //  - Jump instructions (JMP/JCN/JCI/JMI/JSI/JSR)
 //  - OPr modes
 //  - OPk modes
diff --git a/src/uxn-core.s b/src/uxn-core.s
index 7307dce..c290d17 100644
--- a/src/uxn-core.s
+++ b/src/uxn-core.s
@@ -111,16 +111,27 @@ uxn_ret:
     strb    \a, [\off]
 .endm
 
-.macro zload8 dst, off
-    ldrb    \dst, [r7, \off]
+.macro zload8 a, off
+    ldrb    \a, [r7, \off]
 .endm
 
-.macro rload8 dst, off
-    ldrb    \dst, [r0, \off]
+.macro rload8 a, off
+    ldrb    \a, [r0, \off]
 .endm
 
-.macro aload8 dst, off
-    ldrb    \dst, [r7, \off]
+.macro aload8 a, off
+    ldrb    \a, [r7, \off]
+.endm
+
+.macro asave8 a, off
+    strb    \a, [r7, \off]
+.endm
+
+.macro asave16 a, off
+    add     \off, r7
+    strb    \a, [\off, #1]
+    lsr     \a, #8
+    strb    \a, [\off]
 .endm
 
 .macro rsave8 a, off
@@ -684,9 +695,15 @@ lda2:
     b       uxn_decode
 
 sta:
+    wpop16  r4, r5
+    wpop8   r3
+    asave8  r3, r4
     b       uxn_decode
 
 sta2:
+    wpop16  r4, r5
+    wpop16  r3, r5
+    asave16 r3, r4
     b       uxn_decode
 
 dei: