If you already have an earlier version of the DIY Calculator running on your computer, then use the Start > Programs > DIY Calculator > Uninstall DIY Calculator command to remove it from your system. Next, download our new Setup.Zip (software version 4.0.9) file by clicking the icon to the left, select the Save Target As command (or equivalent) from the ensuing pop-up menu or dialog, save the file to the "My Downloads" folder on your computer, and then un-ZIP and install the little scamp. (If you haven’t installed the DIY Calculator before, you may wish to peruse and ponder these installation instructions.)

	The Official DIY Calculator Data Book: Click the icon on the left to download a compressed (ZIP) file containing an Adobe Acrobat version of the Official DIY Calculator Data Book. Amongst other things, Appendix D provides an introduction to the DIY Calculator's assembly language, while Appendix A describes the DIY Calculator's addressing modes and instruction set in excruciating detail. Also, in order to get up-and-running, it would be a good idea to check out some of the step-by-step demonstrations on the Demos page. But remember that the VERY BEST way to learn the DIY Calculator's assembly language – and also to discover how computers perform their magic in intimate detail – is to perform the step-by-step labs in our book How Computers Do Math (if you haven't already done so, why not Purchase a Copy from Amazon right now?)
	Workbench and Terminal (software version 4.0.7): This Adobe Acrobat document – which you can obtain by clicking the icon to the left – describes new Workbench and Terminal utilities that have been added to the DIY Calculator. The workbench contains a election of input switch devices and output display devices (including 8-bit LEDs and 7-segment displays. The terminal comprises a QWERTY keyboard input device and a console (screen) output device. See also the associated Workbench 101 laboratories provided on the Demos page.
	Data Gatherer (software version 3.0.0): This Adobe Acrobat document – which you can obtain by clicking the icon to the left – describes the Data Gatherer utility. Note that the output files generated by the Data Gatherer are intended for use by tools such as the Code Coverage and Code Profiler utilities which are discussed on the More Tools page
	BCD Instructions (software version 2.0.7): This Adobe Acrobat document – which you can obtain by clicking the icon to the left – first introduces the concept of Binary Coded Decimal (BCD); unpacked and packed BCD formats; and unsigned, sign-magnitude, and signed (tens-complement) BCD representations. Next, we introduce the DIY Calculator's new DADD, DADDC, DSUB, and DSUBC instructions, which are tailored to perform BCD operations on BCD data (the "D" prefix for these instructions stands for "Decimal").

Version 4.0.9:	01/16/2006	Small updates to the DIY Calculator's virtual QWERTY keyboard. The <Esc> key has been made non-sticky while the <Tab> and '*' keys have been "tweaked" (these keys generate codes of $1B, $0B, and $2A, respectively).
Version 4.0.7:	01/08/2006	DIY Calculator augmented with Workbench utility (switches and display devices) and Terminal utility (QWERTY keyboard and Console display).
Version 3.0.0:	09/18/2005	DIY Calculator augmented with Data Gatherer utility (also the problem with the calculator not terminating correctly has been fixed).
Version 2.0.7:	08/17/2005	DIY Calculator and Assembler augmented to support new Binary Coded Decimal (BCD) instructions.
Version 1.0.2:	01/01/2005	Original version of the DIY Calculator as supplied with the book.