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Joined: 05/06/2004
Location: AustraliaPosts: 5189
| Posted: 12:55pm 20 May 2011 |
Good find Vasi, especially if the MMBasic can be uploaded into it.
Today I fitted a heat sink to the LM7805 regulator. Its recommended in the construction manual to fit a heat sink if you intend to run the Maximite on 12 volts or more, and I'm glad I took the advice, at 13 volts the home made heat sink gets warm. There's not a lot of room though. Be careful with the LM1117T regulator next door, its metal tab is at 3.3 volts, not a 0 volts like the LM7805. In other words, don't mount both regs on the one heat sink without insulating them.
I also fitted a piezo speaker to the audio output.
Spent a few hours porting a favorite old program to the Maximite. Porting software teaches you the differences in BASIC version, as you encounter errors and learn how the commands behave. One example, LOCATE A,B in QBasic locates a cursor on the screen, from where you can print text using the PRINT command. A is the row, and B is the column. If I wanted to print the letter A in the center of a 80*24 screen, I would use LOCATE 12,40 : PRINT "A"
The Maximite is different. Its LOCATE X,Y, where X & Y are coordinates in pixels. VGA screen size is 480,432, so to print A from dead center I use LOCATE 240,216 : PRINT "A". This also means, even though the manual says the Maximite VGA screen is 80 characters wide, 36 lines, you can in fact position text in pixel steps instead of character steps like the computers of old. Thats good. Also worth noting, each character is 6 pixels wide and 10 height.
The other trick is the Maximite is can run some commands in the background, like SOUND, to play tones. You need to allow for the fact the Maximite will start the command and move on to the next command before the first command has finished. So SOUND 1000,500 will make a 1kHz tone for 500mS, but SOUND 1000,500 : SOUND 2000,1000 will only make a 2kHz sound for 1 second. Its started playing the first sound, but then moved straight onto the 2nd sound before the first sound finished. SOUND 1000,500 : pause 500 : sound 2000,1000 fixes it, adds a pause after the first sound command, so it gets a chance to play before the 2nd sound starts.
This is just some of the stuff I learned while porting the little Connect Four game. Heres a screen shot.
I originally found this game on a Microbee demo tape, and remember spending hours playing it. You play against the computer, and it a tough competitor! I've ported it to GWBasic, QBasic and now MMBasic, and added a few features along the way. I don't know who originally wrote the original Microbee version unfortunately.
Anyway, for those who have received their Maximites, here's MMFour for you to have a go at. If you like it let me know.
2011-05-20_225000_MMFour.zip
Glenn
The best time to plant a tree was twenty years ago, the second best time is right now.
JAQ