TITLE: ADVENTURES INSTALLING A TRANSMISSION IN A BUTTERFLY
SUBTITLE: JOYSTICK TO GEAR-SHIFT, A SLICK GEAR-CHANGER
PURPOSE:
- Discuss programming methods used to reduce size of four-speed routine for AVR Butterfly in AVR machine language.
-
1. BACKGROUND
2. CRIPPLED BUTTERFLIES
3. QUESTIONS ON LIFE IN THE FAST LANE
4. BIRTH OF A TRANSMISSION
5. A MATCH MADE IN HEAVEN
6. A TIGHT CURVE IN THE ROAD
7. SHARING A PIECE OF ARSE
8. REDUCTUM AD ABSURDUM
9. CONCLUSION
10. FEED-BACK AND COMMENTS
- Many moons ago when Atari 800's and C64's ruled the earth and I was a novice programmer. I ran across a programming technique I call a cascade, although it's more like a ladder or stair. I can't remember where exactly, but I think I saw it while browsing either the original IBM BIOS ROM code or the Atari 800 O/S ROM where a series of checks was being made and an Error Code variable was incremented at each step.
What I great idea I thought. Not only does it save on memory, rather than having to load a value for each error condition (2 bytes), all that was required was a single INC. And the error code would indicate how far you got into the setup before things went awry to boot!
Although not exactly the same, I use a similar technique at some point in the following discussion.
- Some of the programming techniques I use in this and other posts may be outside normal programming practices and offensive to conservative programmers.