CV 3.0/3.1 Prohibit Input of Period (2Eh) into Memory Window

ID Number: Q65241

3.00 3.10 | 3.00 3.10

MS-DOS | OS/2

buglist3.00 buglist3.10 fixlist3.11

Summary:

When viewing memory in byte format in a memory window in CodeView

version 3.0 or 3.1, you cannot change the value of a byte in memory to

the hexadecimal value 2E. The hex value 2E has an ASCII character

equivalent of the period ("."). In CodeView, a period is used to

display any nondisplayable character (for example, null, a carriage

return, control characters, and so on), which means the period

character can sometimes have special meaning to CodeView when it

appears in a memory window.

Microsoft has confirmed this to be a problem in CodeView versions 3.0

and 3.1. This problem was corrected in CodeView version 3.11.

More Information:

Because of the special usage of the period character in a memory

window, CodeView versions 3.0 and 3.1 do not allow periods to be typed

directly into memory. In CodeView 3.0, attempts to change a byte value

to 2E result in either the 2 or the E being entered and the other

digit being ignored, depending on which value you enter first. In

CodeView 3.1, both the 2 and the E are returned to their original

values once they have both been entered. If you move to the right side

of the memory window where the ASCII equivalents are shown and you try

to type in a period there, CodeView will also ignore that input.

If you switch the memory window so that you are viewing memory in

ASCII mode, actual periods can be typed in to any memory location.

However, there is a problem with this because ALL other periods on the

same line, which really represent various nondisplayable ASCII

characters, are all converted to 2Es.

If you are viewing memory in a format other than bytes or ASCII,

CodeView will allow a 2E to be entered. The workaround, then, if a

period needs to be entered into memory, is to choose a different

viewing mode other than ASCII or byte-mode, and then enter the period

in the desired location as the value 2E. You can cycle through the

available memory viewing modes by repeatedly pressing SHIFT+F3, or you

can select the desired mode from the Memory Window option on the

Options menu.

Additional reference words: decimal point dot 3.00 3.10