I just learned about the Console command that changes the title of the window in VB 2005 or VB 2008. I wrote a simple calculator program as a Console application and added the instructions in the title, rather than repeat it on the output screen. I also added more console features that lengthen the screen and give the user option to scroll when reaching the bottom or clearing the screen. Program is designed to permit only valid inputs for the operators. Incorrect number inputs will return 0. Other features were added and improved as I edited the code later this evening.

Start a new Console application and copy/paste this code. It should automatically indent each line properly inside the IDE, but you will need to add more spaces in the title string (in place of the underlines) to separate the instructions for Space and Esc:





Module Module1

Sub Main()
Dim oper As String, first, num As Double, over As Boolean
Dim start As Boolean = False
Dim result As Double = 0
Dim ent As String = ""
Dim sresult As String = ""
Dim repeat As Integer = 0
Dim lresult As Long = 0
Dim row As Integer = 0
Console.WindowHeight = 38
Console.Title = "Console Calculator ---- Operators + - * / \ ^ Mod ___ Space clears; ___ Back restarts; ___ Esc exits"
Do
repeat += 1
over = False
If result = 0 And start = False Then
Console.Write("Enter the first number: ")
ent = Console.ReadLine()
Double.TryParse(ent, result)
Console.WriteLine()
Else
Console.WriteLine("The starting number is " & result)
Console.WriteLine()
End If
Console.Write("Type operator, space, Backspace, or Esc: ")
Do
oper = Console.ReadKey(True).KeyChar
oper = oper.ToLower()
Loop While ("+-*/\^m " & Chr(27) & Chr(8)).IndexOf(oper, 0) = -1
If oper = "m" Then
Console.Write("Mod")
Else
Console.Write(oper)
End If
Console.WriteLine(vbCrLf)
If "+-*/\^m".IndexOf(oper, 0) > -1 Then
Console.Write("Enter the second number: ")
ent = Console.ReadLine()
End If
Double.TryParse(ent, num)
first = result
Select Case oper
Case "+"
result += num
Case "-"
result -= num
Case "*"
result *= num
Case "/"
If num = 0 Then num = 1
result /= num
Case "\"
lresult = Convert.ToInt64(result)
lresult \= Convert.ToInt64(num)
result = lresult
Case "^"
result ^= num
If result > 1.79769313486231E+308 Or result < -1.79769313486231E+308 Then
result = first
sresult = ("Result is beyond upper or lower limit")
over = True
End If
Case "m"
result = result Mod num
oper = "Mod"
Case " "
result = 0
Console.Clear()
start = False
repeat = 0
Case Chr(8)
row = Console.CursorTop
Console.CursorTop = row - 4
Console.CursorLeft = 0
Console.Write(StrDup(160, " "))
Console.CursorTop = row - 4
result = 0
start = False
Case Chr(27)
Exit Do
Case Else
oper = " "
Console.Clear()
End Select
If over = False Then sresult = result.ToString
If oper <> " " And oper <> Chr(8) Then
Console.WriteLine()
Console.WriteLine(vbTab & first & " " & oper & " " & num & " = " & sresult)
Console.WriteLine()
Console.Write(StrDup(80, "="))
End If
If oper <> " " And oper <> Chr(8) Then start = True
If repeat Mod 4 = 0 And Console.CursorTop >= 34 Then
Console.WriteLine("Enter to clear screen, Tab to scroll to top, any other key to continue down...")
ent = Console.ReadKey(True).KeyChar
If ent = Chr(13) Then
Console.Clear()
repeat = 0
ElseIf ent = Chr(9) Then
Console.CursorTop = Console.CursorTop - 1
Console.WriteLine(StrDup(80, " "))
Console.CursorTop = Console.CursorTop - 2
Console.WindowTop = repeat * 9
Else
row = Console.CursorTop
Console.CursorTop = row - 1
Console.CursorLeft = 0
Console.Write(StrDup(80, " "))
Console.CursorTop = row - 1
End If
End If
Loop Until oper = Chr(27)
Console.WriteLine(vbCrLf)
Console.WriteLine("Press any key to Exit Console Calculator")
Console.ReadKey(True)
End Sub

End Module