feat: Started working on a catalan numbers program

4 files changed, 71 insertions, 0 deletions

diff --git a/catalan/Makefile b/catalan/Makefile
new file mode 100644
index 0000000..596e512
--- /dev/null
+++ b/catalan/Makefile
@@ -0,0 +1,17 @@
+AS=xa
+FILES=catalan.a65
+VICE=x64
+VICEFLAGS=-VICIIfilter 0 +confirmonexit
+
+.PHONY: build execute run
+
+build:
+	$(AS) $(FILES) -o catalan.prg
+
+dump:
+	$(AS) $(FILES) -P - -o /dev/null
+
+execute:
+	$(VICE) $(VICEFLAGS) *.prg >/dev/null
+
+run: build execute
diff --git a/catalan/basic_starter.a65 b/catalan/basic_starter.a65
new file mode 100644
index 0000000..5242418
--- /dev/null
+++ b/catalan/basic_starter.a65
@@ -0,0 +1,32 @@
+/* PRG format
+ *   Contains two bytes of header data, address from which
+ *   the rest of the file will be loaded into memory.
+ * BASIC memory starts at addr 2048, we effectively place "10 SYS 2064"
+ * and an end of program after it. Then immedately afterwards
+ * we place our command on addr 2064.
+ *   When BASIC loads up, it runs "10 SYS 2064" and passes up execution there.
+ *   Then, when we return, we get a zero which indicates termination.
+ */
+
+/* The starting address is defined by the value (label or alias) "main".
+ * Since in basic we need to provide a decimal string, but we store a decimal value, we need
+ * to do this complicated convertion.
+ */
+#define main_addr_ch1 "0" + main / 10000
+#define main_addr_ch2 "0" + (main - main / 10000 * 10000) / 1000
+#define main_addr_ch3 "0" + (main - main / 1000 * 1000) / 100
+#define main_addr_ch4 "0" + (main - main / 100 * 100) / 10
+#define main_addr_ch5 "0" + main - main / 10 * 10
+
+.word $0801 ; Header -- addr 2049
+* = $0801   ; Program Counter
+
+.(
+	.word eol
+	.word 10
+	.byt $9e," "
+	.byt main_addr_ch1,main_addr_ch2,main_addr_ch3,main_addr_ch4,main_addr_ch5,0
+eol	.word 0
+.)
+
+// vim: noet ts=8 sw=0 lcs=tab\:\ \ 
diff --git a/catalan/catalan.a65 b/catalan/catalan.a65
new file mode 100644
index 0000000..5b544a2
--- /dev/null
+++ b/catalan/catalan.a65
@@ -0,0 +1,9 @@
+#include "basic_starter.a65"
+#include "kernal.a65"
+
+hello	.byt "HELLO, WORLD!",0
+
+main	print(hello)
+	rts
+
+// vim: noet ts=8 sw=0 lcs=tab\:\ \ 
diff --git a/catalan/kernal.a65 b/catalan/kernal.a65
new file mode 100644
index 0000000..40db36f
--- /dev/null
+++ b/catalan/kernal.a65
@@ -0,0 +1,13 @@
+#define putchar() jsr $FFD2
+
+#define print(str) .(                          :\
+	ldx #0       ; x = 0                   :\
+loop 	lda str, x   ; while (_1[x] != 0)      :\
+	beq end                                :\
+	putchar()    ;    putchar(_1[x])       :\
+	inx          ;    ++x                  :\
+	bne loop     ;    if (x == 0) break    :\
+end                                            :\
+.)
+
+// vim: noet ts=8 sw=0 lcs=tab\:\ \