One of the biggest interface problems involved in designing Hexulator is that there aren't enough keys on the numeric key pad for all the digits and operators needed for a hexadecimal calculator.
Decimal mode key entry is straightforward: the keys work just as they are labeled on the key caps.
For Hex mode key entry, there are two strategies. One involved using the A,S,D, and F keys to represent the top row of keys (the operators). Z,X,C, and V represent the memory keys.
The other strategy involves using the <shift> key. When you hold down the shift key in hex mode, you can use the operator buttons on the numeric keypad. With a little practice, you'll be able to enter equations quickly using either mode (personally, I use the latter).
SYSTEM REQUIREMENTS:
Hexulator works on any Macintosh equipped with System 7.0 or above. A numeric keypad is required to access Hexulator commands from the keyboard, but PowerBook users can still use Hexulator by clicking on the buttons with the trackball.
Do I need to keep my 'Calculator' DA?
Hexulator can replace the calculator that came with your system software. There are only two circumstances in which you may prefer the latter:
• You use numbers larger than 2,147,483,648. This is the largest number that Hexulator can display in the decimal register. The calculator desk accessory can compute much larger numbers.
• You are very short of disk space or RAM: Thirty kilobytes here or there is no great concern for most users, but the calculator requires only about one quarter the disk space and a third the RAM that Hexulator needs.
For any other purpose, Hexulator is superior to the standard "Calculator" DA.
Hexulator recognizes the following conditions and will display the appropriate message in the decimal register. If the condition is such that the data shown is invalid, red marks will appear on either side of the registers and you will have to <clear> before you can continue.
Overflow Error: The value is greater than 0xFFFFFFFF. You cannot continue after an Overflow Error.
Decimal Over: The decimal register can display only numbers from 0..0x80000000 (0..2,147,483,648). From values between 0x80000001..0xFFFFFFFF, the decimal register shows the "Decimal Over" message. You can continue after getting this message, but no number will appear in the decimal register unless the value falls to 0x80000000 (2,147,483,648) or less.
Neg Num Error: If a subtraction operation yields a negative result, The hexadecimal register will display the message "NEGATIVE". No number will appear in the hex register until the value becomes greater than zero.
As the makers of the Intel Pentium chip can attest, it's very difficult to develop a 100% fault-free program. Since Hexulator is for use in developing software, it's very important that you can trust the results the program gives you.
If any calculation you make using Hexulator yields an incorrect result, please contact me (through e-mail, if possible) as soon as possible. Try to give me as much detail as you can: the equation that yielded the incorrect result as well as the program's settings (whether you were working in hex or decimal mode, the number of decimal digits of precision, etc...)
Also, please contact me if Hexulator seems to act strangely in any way. It has been stress tested on a number of platforms, but it is impossible for me to guarantee 100% compatability with every processor and every system.
Hexulator was developed on a PowerMac 7100 using MetroWerks CodeWarrior C, more than a few volumes of Inside Macintosh and, ironically, Hexulator itself.
