I don't want to sound condescending but why can't these systems be rewritten in a modern language? Now is obviously not the right time to do this; I am wondering are there technical limitations to do his?
Here's some simple COBOL code: http://www.csis.ul.ie/cobol/examples/Conditn/Conditions.htm identification division. program-id. letters. data division. working-storage section. 01 Char PIC X. 88 Vowel VALUE "a", "e", "i", "o", "u". 88 Consonant VALUE "b", "c", "d", "f", "g", "h" "j" THRU "n", "p" THRU "t", "v" THRU "z". 88 Digit VALUE "0" THRU "9". 88 ValidCharacter VALUE "a" THRU "z", "0" THRU "9". procedure divisio…
sub letters
dim char as string
do
char = inputbox("Enter lower-case character or digit. No data ends.")
select case char
case "a", "e", "i", "o", "u"
msgbox "The letter " & char & " is a vowel."
case "b", "c", "d", "f", "g", "h", _
"j" to "n", "p" to "t", "v" to "z"
msgbox "The letter " & char & " is a consonant."
case "0" to "9"
msgbox char & " is a digit."
case else
exit do
end select
loop
end sub
(This example is actually LibreOffice Basic, as I'm not on a Windows machine right now, but it should be the same in VBA and VB6.)