100 cls : rem  100 home  for Applesoft BASIC
110 roman$ = "MCMXCIX" : print roman$,"=> "; : gosub 170 : print decimal '1999
120 roman$ = "XXV" : print roman$,"=> "; : gosub 170 : print decimal     '25
130 roman$ = "CMLIV" : print roman$,"=> "; : gosub 170 : print decimal   '954
140 roman$ = "MMXI" : print roman$,"=> "; : gosub 170 : print decimal    '2011
150 end
160 rem Decode from roman
170 decimal = 0
180 predecimal = 0
190 for i = len(roman$) to 1 step -1
200  x$ = mid$(roman$,i,1)
210  if x$ = "M" then n = 1000 : goto 280
220  if x$ = "D" then n = 500 : goto 280
230  if x$ = "C" then n = 100 : goto 280
240  if x$ = "L" then n = 50 : goto 280
250  if x$ = "X" then n = 10 : goto 280
260  if x$ = "V" then n = 5 : goto 280
270  if x$ = "I" then n = 1
280  if n < predecimal then decimal = decimal-n
285  if n >= predecimal then decimal = decimal+n
290  predecimal = n
300 next i
310 return