Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watmath!clyde!cbosgd!ihnp4!ptsfa!ames!think!husc6!mit-eddie!apollo!tbg From: tbg@apollo.UUCP Newsgroups: comp.sys.ibm.pc Subject: 256 colors on Model 50 Message-ID: <35f56031.d5c4@apollo.uucp> Date: Thu, 9-Jul-87 12:00:00 EDT Article-I.D.: apollo.35f56031.d5c4 Posted: Thu Jul 9 12:00:00 1987 Date-Received: Sun, 12-Jul-87 01:23:53 EDT Organization: Apollo Computer, Chelmsford, Mass. Lines: 44 Keywords: Progress Report Thanks to all those who have been responding with info on the 256 color mode on the VGA. Right after I sent my original query I saw and bought the Technical Reference for the 50/60 (my dealer had no idea how to get one) and it confirmed my hunch that mode 19 (decimal) was correct. Unfortunately the information on programming the DAC to initialize the pallette (so I can select what 256 I want to display) is not great. I tried doing it from Turbo-C without any success. A note in the technical reference manual says something about there being routines in the BIOS to do this for me... ...so, it looks like I need to keep hacking away and/or try to find the new BIOS technical reference. I tried this routine (reproduced from memory; I don't have a printer at home yet) in Turbo-C: load_lut(index,red,green,blue) char index,red,green,blue; { disable(); /* disable interrupts */ pokeb(0,0x2ce8,index); /* write index addr into pel register */ pokeb(0,0x2ce9,red); /* note: "0x2ce8", and "0x2ce9" are from */ pokeb(0,0x2ce9,green); /* memory and are probably not */ pokeb(0,0x2ce9,blue); /* what I actually tried last night */ enable(); /* enable interrupts */ } I am assuming "pokeb" is the right method for accessing a register location (I am new to 8086 stuff. the first argument is supposed to be the segment). Similar attempts to read the DAC as instructed in the technical reference returned all ones (-1). Anyway, I was unable to change any LUT locations. (I am displaying all 256 colors). /tom