unignored readme

.gitignore

@@ -0,0 +1,5 @@
+*
+!*.rkt
+!old-code
+!README.md
+!.gitignore

README.md

@@ -0,0 +1,51 @@
+# zybino: LR35902ish racket language
+
+very early days for now.
+
+in the racket repl:
+
+```
+ (run-lines (list
+  (8b-ld-reg-imm 4 #x01)
+  (8b-ld-reg-imm 5 #x50)
+  (8b-ld-reg-imm 7 #x69)
+  (8b-ld-reg-reg 6 7)
+  (8b-ld-reg-reg 7 4)
+  (8b-ld-reg-imm 5 #x51)
+  (8b-ld-reg-reg 6 7)))
+```
+
+will evaluate to:
+
+```
+PC: $07, SP: $00, Flags: %00000000
+BC: $0000, DE: $0000
+HL: $0151, AF: $0100
+(HL): $01
+$0150 > $69 $01 $00 $00 $00 $00 $00 $00 $00 $00 $00 $00 $00 $00 $00 $00 < $0160
+```
+
+which is the equivilent of:
+
+```
+LD H, $01
+LD L, $50
+LD A, $69
+LD (HL), A
+LD A, H
+LD L, $51
+LD (HL), A
+```
+
+# notes
+
+register numbering is following how the LR35902 decodes instructions, as such:
+
+   * 0: B
+   * 1: C
+   * 2: D
+   * 3: E
+   * 4: H
+   * 5: L
+   * 6: (HL)
+   * 7: A