Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: Notesfiles $Revision: 1.6.2.17 $; site waltz.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!ihnp4!inuxc!pur-ee!uiucdcs!waltz!haddock From: haddock@waltz.UUCP Newsgroups: net.micro Subject: Re: TMS9918A Help Wanted Message-ID: <30700005@waltz.UUCP> Date: Wed, 16-Jan-85 03:40:00 EST Article-I.D.: waltz.30700005 Posted: Wed Jan 16 03:40:00 1985 Date-Received: Fri, 18-Jan-85 02:24:55 EST References: <22300008@uok.UUCP> Lines: 45 Nf-ID: #R:uok:22300008:waltz:30700005:000:1397 Nf-From: waltz!haddock Jan 16 02:40:00 19853C00 R4 = 00 R5 = 00 R6 = 00 R7 = 00 Pattern color tbl = >2000 Pattern generator tbl = >0000 2. Fill Pattern Name Table with 0 to 255 (do 3 times [3*256=768]) 3. Fill Pattern Generator Table with 0's 4. Fill Pattern Color Table with color pairs (backgrnd and plot color) 5. WHILE no more (x,y) DO get_pair(x,y) plot(x,191-y) /* Adjust for upper left = (0,0) while (x,y) has normal origin */ END Plot(x,y) Pattern# = |x/8| + |y/8|*32 /* |x| = integer_part(x) */ /* ^-- Don't skimp here! Those LSBits need to be zero'ed */ Pattern#_offset = Pattern# * 8 + (y MOD 8) /* = which byte on screen */ VDP_addr = Pattern#_offset + base address of Pattern Generator Table contents_of(VDP_addr) |= bitmask[x MOD 8] /* bitmask[]={>80,>40,>20,...,>01} */ Return ================================================================ _____ -Rusty- |\/ o \ o | ( -< O o Where's the fish? |/\__V__/ ARPA: Haddock%Waltz%TI-CSL@CSNet-Relay Rusty@Maryland (forwarded to CSNet address) CSNet: Haddock@TI-CSL USENET: {convex!smu, ut-sally, texsun, rice} ! waltz ! haddock