From: Brian Ketterling (tweel8502_at_hotmail.com)
Date: 2003-10-29 00:54:53
Hi -- With a little closer study I guess I've answered my own questions -- thanks, Willi and John, for being a sounding board and helping me focus! I don't know if anyone else will ever be interested in passing big numbers back and forth between BASIC and ML, but... It turns out that the routine at BC9B is called by BASIC's INT() function. It literally turns the f.p. number into a binary integer, then converts it back again to f.p. I was wrong about the format of negative numbers. It doesn't flag them with the MSbit, but instead does a complement-thing, e.g.: -1 = FF FF FF FF -2 = FF FF FF FE Also, INT's floor-function operation (+1.1 becomes +1, -1.1 becomes -2... always downward) is built into the first conversion routine at BC9B. So, negative numbers could be a hassle, but for passing positive 4-byte integers to BASIC, it looks like you just have to preload $62-$65 with the number (highest byte first), LDY #0, then jump into INT with JSR $BCD5. The result will be in FAC1. -- Brian _________________________________________________________________ Surf and talk on the phone at the same time with broadband Internet access. Get high-speed for as low as $29.95/month (depending on the local service providers in your area). https://broadband.msn.com Message was sent through the cbm-hackers mailing list
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