It's been quite a while since I had a build environment for the DOS fractint. My last one was lost when my oldest home-built PC running Windows XP died (though the disks are fine). So today I finally decided to do something about it. I'm not going to give all the steps because I doubt they apply to many (if any) of you, but if anyone is interested, ask. I still have my original Windows XP professional disc, as well as a service pack 2 slipstreamed copy I made many moons ago (and have forgotten how that was done) and a service pack 3 upgrade I downloaded. 1. I installed my Windows XP SP2 DVD into Oracle VirtualDisk under Windows 10. 2. I upgraded XP to Service Pack 3. 3. I validated the Windows XP copy with Microsoft even though I still had 30 days. Tedious but no problems, had to copy a lot of numbers. 4. I copied my c and assembler compiler directories c:\c700 and c:\masm611 from the dead machine hard drive. Thankfully there was no need to reinstall since the originals are on on zillions of floppies, and I don't even know if they are readable! 5. I set environment variables for INCLUDE, LIB, and PATH for both the C/C++ and MASM611 6. I copied the source files for fractint over, deleted any object code, created a DOS window, and inside the source directory invoked makefrac.bat. Voila! After about a minute, everything compiled, and the fractint.exe executable ran perfectly. All the VESA video support worked fine under VirtualDisk, even better than on the old dead XP machine. This is a terrific environment for maintaining the DOS Fractint. Flush with success, I tried the same thing on an older Windows 7 machine that has Microsoft's built in XP Mode. I could not get it to work for reasons I don't understand (makefrac.bat gave errors). I have limited scientific interest in that platform since I have virtual XP under Windows 10 working. Next step will be to get an SDL build environment working. Note that for different reasons than Jonathan, I too have limited hours to spend on fractint, so there's no telling when I'll get to this. Jonathan has a demanding job. I am happily retired, with a very full life. I guess that's a good thing. That said, the above steps rebuilding the DOS version build environment took the better part of a Saturday, and I have SDL on my mind, so will try to get to it. Tim