GW-BASIC : Line Numbering Practice 2

[kimpro82]

• Finally I've got GW-BASIC 3.23!

[kimpro82]

• Variances in Basic highest line numbers (retrocomputing.stackexchange.com)

  Line numbers are stored as a two byte word but the largest allowed by the input routines is 65529. Primarily because this is an easier limit to test rather than checking for overflow. The line number is converted from ASCII to binary a character at a time using a pretty standard algorithm. Start with a 16 bit value line = 0. For each digit multiply line by 10 and add the digit to line.

  To check if the line number is acceptable, compare line against 6552 before multiplying it by 10. This will guarantee the value is <= 65529 because a digit can add only 9 at most.

[kimpro82]

• Answers from Bing

  In GW-BASIC, an exclamation mark after a variable name indicates that the variable is of the SINGLE data type, which is a floating-point number with single precision. For example, x! would be a variable of the SINGLE data type.

  In GW-BASIC, when you use an integer constant like 10 or 20 in your code, it is automatically treated as an integer. However, if you want to explicitly specify that a number is a SINGLE data type, you can add an exclamation mark after the number, like 10! or 20!. Is there anything else you would like to know?

  In GW-BASIC, the SINGLE data type is used to store floating-point numbers with single precision. A SINGLE variable can store a number with up to 7 digits of precision and an exponent range of -38 to +38. The SINGLE data type is useful for storing numbers that require decimal places, such as 3.14 or 0.1234. Is there anything else you would like to know?

[kimpro82]

• Microsoft > Learn > Documentation > .NET > Visual Basic > Single Data Type

  This is not exactly GW-BASIC, but it is a descendant with some traces of its syntax.

  Type Characters. Appending the literal type character F to a literal forces it to the Single data type. Appending the identifier type character ! to any identifier forces it to Single.