created scaffolding for import export code

src/bas/mlloader.bas

@@ -0,0 +1,36 @@
+10REM Main menu
+20CLEAR:CLS
+30PRINT "MACHINE LANGUAGE LOADER"
+40N=PEEK(&H7FFF)*256+PEEK(&H7FFE)-1
+50GOSUB 1000
+60IF N<256 THEN PRINT "user area: NOT RESERVED":GOTO 70
+65PRINT "user area: 0100H-";H$
+70PRINT "work area: ";FRE;" bytes"
+80PRINT "< Load   Save   Verify >"
+90S=0
+100K$=INKEY$
+110IF K$="L" GOSUB 2000
+120IF K$="S" GOSUB 3000
+130IF K$="V" GOSUB 4000
+140IF S=0 GOTO 100
+150GOTO 20
+999END
+1000REM Converts the value of N into a hex-string and stores the result in N$
+1010H$=""
+1020FOR I = 3 TO 0 STEP -1
+1030A=15:IF I=3 THEN A=7
+1040T=(N AND (A*(16^I))) / (16^I)
+1050IF T<10 THEN H$=H$+CHR$(T+48):GOTO 1070
+1060H$=H$+CHR$(T+55)
+1070NEXT I
+1080H$=H$+"H"
+1090RETURN
+2000REM Loads a memory area from file
+2010S=2000
+2999RETURN
+3000REM Saves a memory area to disk
+3010S=3000
+3999RETURN
+4000REM Compares a memory area with the file on disk
+4010S=4000
+4999RETURN