/************************** I2ICE TUTORIAL SCREEN #28 **************************/
menu=1
define literally P   = 'include scr.27 nolist'
define literally R   = 'include scr.28 nolist'
define literally RTN = 'include scr.28 nolist'
define literally N   = 'include scr.29 nolist'
define literally M   = 'include scr.2 nolist'
cls
/*******************************************************************************/
'                                                      ------------------------'
'The conversion from CHAR to VALUE should occur on    | SCR28: BUG EXPLAINED   |'
'lines 70 and 71 (shown below).                       | M = Go to main menu    |'
'  70  VALUE = VALUE + CHAR - ''0''                     | N = Next screen        |'
'  71  VALUE = VALUE /10                              | P = Previous screen    |'
'Let''s simulate three passes through these lines      | Q = Quit tutorial      |'
'that occur when you enter the ASCII-coded hex values | R = Rewrite SCR28      |'
'for 150 (CHAR, as a result, is set successively to   | SCR# = Screen desired  |'
'the ASCII-coded bytes 31, 35, and 30).  Note that     ------------------------'
'VALUE is initialized to 0 and the symbol ''0'' shown   '
'in line 70 equals the ASCII value for 0 (30H).       '
'  First loop pass     70   VALUE = 0 + 31 - 30 = 1'
'                      71   VALUE = 1/10 = 0'
'  Second loop pass    70   VALUE = 0 + 35 - 30 = 5'
'                      71   VALUE = 5/10 = 0'
'  Third loop pass     70   VALUE = 0 + 30 - 30 = 0'
'                      71   VALUE = 0/10 = 0'
'Now we know why VALUE is always 0.  Apparently the programmer switched the'
'two lines and divided rather than multiplied.  Lines 70 and 71 should be'
'  70  VALUE = VALUE * 10'
'  71  VALUE = VALUE + CHAR - ''0'''
'-------------------------------------------------------------------------------'