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The older Mr. Cool

New version of Mr. Cool.  Or, old version — it doesn’t support the PCjr.

There are a couple of differences, this version loads the game into 90:0, while the PC/PCjr loads into 80:0…  This version also has a bug in the define keys routine. I was using 7/9/1/3 to move (keypad with numlock on), but if you choose those keys in this version, it won’t print the keys properly. They assume that you’re pressing a letter without actually checking, and then do an AND AL,0DFh to get the uppercase of that letter. However, that doesn’t work very well if you press anything other than a letter.

The PC/PCjr version does a CMP AL,61h (lowercase a), and doesn’t do the AND if the key pressed is “below” that.  Also, in the PC version, you can press Tab to get back to the selection screen. This doesn’t work on the PC/PCjr version, because for some reason, it does a different check.

The PC version just checks AL for 9 (tab), and if so, jumps to the selection screen. The PC/PCjr version first checks AL for 9, then checks AH for 0Fh (which is the scan code, and according to what I found online, the scan code for Tab is 0Fh), and if this is also set, it jumps away from running the selection screen.   I made a few updates to the DOSrip, along with the image file of this PC only version…

Now I have to eat and get ready for work 😉



About Trixter

I am a child of the early 1980s, defined by the personal computer explosion and post-modern style of that era. Despite that upbringing, I am not a Mac lover (although I don't hate them either). My hobbies are centered on a particular pocket of the Nerd universe that includes the demoscene, MobyGames, Mindcandy DVDs, and 8088/CGA assembler programming. There is a trend there -- see if you can find it in my writing. My parents made sure I witnessed the first launch of the Space Shuttle, and also the first broadcast hour of MTV (which, coincidentally, also included a launch of the Space Shuttle). I think that says a lot about who I am.

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