Jonathan asked:
Is the BN math faster than BF?
BN is like integer math, only with a huge integer. It's fixed point with a lot of digits. It is faster than BF math. BF math also manages the exponent and so has more dynamic range. I'm at a disadvantage here because my development environment is not accessible so I can't look to check my facts ... I think fractint starts out with BN math and then uses BF math later when the zoom depth is greater.
What is Fractint doing different that allows it to work?
I don't know the answer to this.
Would there be any advantage to switching to Watcom for continued support of DOS Fractint?
The main advantages are that Watcom is now actively maintained open source so anyone could intstall the environment and help, and it supports both legacy memory modes such as we use and windows development. Theoretically one should be able to compile the DOS fractint and the WIndows 3.1 Winfract. But I wouldn't necessarily recommend that you look into Watcom, because it might take some work to port to Watcom (mostly figuring out overlay support) , and when you are done, you'd have what you started with - a medium model Fractint. We have a whole lot of choices of development environments we have investigated and could investigate. Having said that, I don't mean you shouldn't look into it, just trying to explain what Open Watcom is. The SciTech guys are maintaining Watcom. I recall their helping us in Fractint's early days. Changing subjects ... My symptoms on my old HP Pavillion with my Fractint environment are that it said the bios failed a checksum and it took me into the bios. I set the time and date and proceeded with the boot. It made it a fair way into the boot process and hung with a screeching sound. It boots OK to safe mode, and it boots a CD with Bart's PE (Windows XP) environment. I restored earlier images to no avail, so I don't think it's Windows update gone bad. The PC can't be too horribly broken. I'll pursue it a little while longer, but what I should really do is get MSC going on my XP machine. That won't be a big job. I haven't lost any data from my old machine because I am a backup fanatic, and in any case, I can still boot to modes that allow accessing the data. Unfortunately with these complications I can't quickly investigate the Winfract problems to help you out. Tim