Add experimental extract of Applesoft BASIC files

main.go

@@ -4,6 +4,7 @@ import (
 	"flag"
 	"fmt"
 	"os"
+	"strings"
 
 	"github.com/tjboldt/ProDOS-Utilities/prodos"
 )
@@ -68,7 +69,11 @@ func main() {
 		if err != nil {
 			os.Exit(1)
 		}
+		if strings.HasSuffix(strings.ToLower(outFileName), ".bas") {
+			fmt.Fprintf(outFile, prodos.ConvertBasicToText(getFile))
+		} else {
 			outFile.Write(getFile)
+		}
 	case "put":
 		file, err := os.OpenFile(fileName, os.O_RDWR, 0755)
 		if err != nil {

prodos/basic.go

@@ -0,0 +1,157 @@
+package prodos
+
+import (
+	"fmt"
+	"strings"
+)
+
+func ConvertBasicToText(basic []byte) string {
+	var builder strings.Builder
+
+	i := 0
+
+	for {
+		lo := basic[i]
+		i++
+		hi := basic[i]
+		i++
+
+		if lo == 0 && hi == 0 {
+			builder.WriteString("\n")
+			return builder.String()
+		}
+
+		line := int(basic[i]) + int(basic[i+1])*256
+		i += 2
+
+		fmt.Fprintf(&builder, "\n %d ", line)
+
+		for {
+			t := basic[i]
+			if t == 0 {
+				i++
+				break
+			}
+			if t > 127 {
+				builder.WriteString(getToken(t))
+			} else {
+				builder.WriteString(string(t))
+			}
+			i++
+		}
+	}
+}
+
+func getToken(token byte) string {
+	tokens := map[byte]string{
+		0x80: "END ",
+		0x81: "FOR ",
+		0x82: "NEXT ",
+		0x83: "DATA ",
+		0x84: "INPUT ",
+		0x85: "DEL ",
+		0x86: "DIM ",
+		0x87: "READ ",
+		0x88: "GR ",
+		0x89: "TEXT ",
+		0x8A: "PR # ",
+		0x8B: "IN # ",
+		0x8C: "CALL ",
+		0x8D: "PLOT ",
+		0x8E: "HLIN ",
+		0x8F: "VLIN ",
+		0x90: "HGR2 ",
+		0x91: "HGR ",
+		0x92: "HCOLOR = ",
+		0x93: "HPLOT ",
+		0x94: "DRAW ",
+		0x95: "XDRAW ",
+		0x96: "HTAB ",
+		0x97: "HOME ",
+		0x98: "ROT = ",
+		0x99: "SCALE = ",
+		0x9A: "SHLOAD ",
+		0x9B: "TRACE ",
+		0x9C: "NOTRACE ",
+		0x9D: "NORMAL ",
+		0x9E: "INVERSE ",
+		0x9F: "FLASH ",
+		0xA0: "COLOR = ",
+		0xA1: "POP ",
+		0xA2: "VTAB ",
+		0xA3: "HIMEM: ",
+		0xA4: "LOMEM: ",
+		0xA5: "ONERR ",
+		0xA6: "RESUME ",
+		0xA7: "RECALL ",
+		0xA8: "STORE ",
+		0xA9: "SPEED = ",
+		0xAA: "LET ",
+		0xAB: "GOTO ",
+		0xAC: "RUN ",
+		0xAD: "IF ",
+		0xAE: "RESTORE ",
+		0xAF: "& ",
+		0xB0: "GOSUB ",
+		0xB1: "RETURN ",
+		0xB2: "REM",
+		0xB3: "STOP ",
+		0xB4: "ON ",
+		0xB5: "WAIT ",
+		0xB6: "LOAD ",
+		0xB7: "SAVE ",
+		0xB8: "DEF FN ",
+		0xB9: "POKE ",
+		0xBA: "PRINT ",
+		0xBB: "CONT ",
+		0xBC: "LIST ",
+		0xBD: "CLEAR ",
+		0xBE: "GET ",
+		0xBF: "NEW ",
+		0xC0: "TAB ",
+		0xC1: "TO ",
+		0xC2: "FN ",
+		0xC3: "SPC( ",
+		0xC4: " THEN ",
+		0xC5: "AT ",
+		0xC6: "NOT ",
+		0xC7: "STEP ",
+		0xC8: " + ",
+		0xC9: " - ",
+		0xCA: " * ",
+		0xCB: " / ",
+		0xCC: " ; ",
+		0xCD: "AND ",
+		0xCE: "OR ",
+		0xCF: " > ",
+		0xD0: " = ",
+		0xD1: " < ",
+		0xD2: "SGN ",
+		0xD3: "INT ",
+		0xD4: "ABS ",
+		0xD5: "USR ",
+		0xD6: "FRE ",
+		0xD7: "SCRN (",
+		0xD8: "PDL ",
+		0xD9: "POS ",
+		0xDA: "SQR ",
+		0xDB: "RND ",
+		0xDC: "LOG ",
+		0xDD: "EXP ",
+		0xDE: "COS ",
+		0xDF: "SIN ",
+		0xE0: "TAN ",
+		0xE1: "ATN ",
+		0xE2: "PEEK ",
+		0xE3: "LEN ",
+		0xE4: "STR$ ",
+		0xE5: "VAL ",
+		0xE6: "ASC ",
+		0xE7: "CHR$ ",
+		0xE8: "LEFT$ ",
+		0xE9: "RIGHT$ ",
+		0xEA: "MID$ ",
+	}
+
+	return tokens[token]
+}