Path: utzoo!attcan!uunet!convex!killer!ames!mailrus!rutgers!iuvax!bsu-cs!cfchiesa From: cfchiesa@bsu-cs.UUCP (Christopher Chiesa) Newsgroups: comp.sys.atari.8bit Subject: Intermittent Heat-Related System Failure Keywords: heat failure intermittent diagnose help Message-ID: <3204@bsu-cs.UUCP> Date: 30 May 88 19:27:10 GMT Organization: CS Dept, Ball St U, Muncie, Indiana Lines: 234 Greetings. Regular readers of this group may recall my postings over the past several months, dealing with intermittent system problems which I attributed to my aging Percom AT-88 disk drive. Unfortunately, the problem has always been spo- radic enough to elude simple cause-and-effect diagnosis, and the software which locks up has always been complex enough (AtariWriter, AtariWriter Plus, video games) that the problem "could be anything" in the system. Last night, however, all of that changed. I've been working on a little graphics-demo program, in which the "main program" does the well-known "rain- bow" effect with the "background" color, while a VBI routine "rotates" five players (yes, five) horizontally across the central portion of the screen. It's a short program, I understand it thoroughly, and it LOCKED UP on my com- puter three separate times when it absolutely should NOT have. (Code is be- low for those who want it.) From this latest development, I've been able to deduce that yes, the prob- lem IS heat-related. The first time this program locked up, the computer had been on most of the day, and a hot day at that. Thinking back, most of the other failures occurred when one or both of these factors was true. The clin- cher was when I let the program run all night. It ran fine for a half hour before I shut the monitor off at 2AM, then when I turned it back on at 10AM the background ripple was gone, the player graphics data was corrupted, and the program no longer responded to the "exit" command (START+SELECT+OPTION all pressed at the same time.) The "main program," in other words, had died. The VBI routine, however, was still running, rotating the players just as always. THAT seems as though it ought to be significant; can anyone be more specific? On discovering this situation, I felt around the case (this is an 800, not an XL or XE) and found that the hottest place was in the right rear, where as I recall from years ago, the RF drive circuitry lies. (I'm using a monitor so the RF circuit is driving NOTHING; can that be enough of a problem to fry the rest of the machine?) The "personality board" and three RAM boards inside the main hatch (BACK of the cartridge slots) were warm to the near-touch, also. There's a computer place north of here that for ten bucks will examine your computer and tell you what's wrong with it. I am thinking of taking this beast up there, but I sure don't want them to MISS anything. From what I've described, can anyone here suggest the most likely / common cause of this type of problem? I should point out that no one else I've known with an Atari (although most of them are XLs, not originals like mine) has any problem run- ning the VERY SAME COPY of any of the programs that lock up on my machine. Thanks in advance for anything anyone can say. The disk drive problem is one thing, but if my main box is fried that's another story entirely. SPARE NO EXPENSE! etc. Chris Chiesa Ball State University Muncie, IN The following is the code for my short graphics-demo program. Put it on when you go to bed tonight, and see if it is still running properly when you get up tomorrow morning. If it IS, then I've got a problem. If it ISN'T then YOU'VE got the SAME problem. ===========CUT HERE =============== CUT HERE ================================= ; STRIPES -- "moving stripes" graphics demo ; v4.1, Chris Chiesa, 5/29/88 ; RTCLOK = $14 SDMCTL = $022F GPRIOR = $026F SIZEP0 = $D008 GRAFP0 = $D00D COLPM0 = $D012 COLBK = $D01A CONSOL = $D01F POT0 = $D200 WSYNC = $D40A SETVBV = $E45C SYSVBV = $E45F XITVBV = $E462 ; VBI = $06 ; "Immediate VBLANK Vector" - for SETVBV routine ALLKEYS = $07 ; CONSOL value when OPTION, SELECT, START all pressed COLRINC = $10 ; Color-rotation increment (players): clr +1, lum +0 ; DMADSB = $00 ; Turn display off entirely DMAPM = $0C ; Enable Players/Missiles only DMAENB = $22 ; Enable normal playfield display ; LMAR = $40 ; P/M coordinate "Left Margin" MID = $A0 ; P/M coordinate "threshold" RMAR = $C0 ; P/M coordinate "Right Margin" ; *= $2000 COLREG .BYTE 0 ; temporary Color Register POSARR .BYTE $40,$60,$80,$A0,$C0 ; P/M positions 0 - 4 DATARR .BYTE $FF,$FF,$FF,$FF,$00 ; P/M graphic data, 0 - 4 ; START JSR INIT ; Initialize P/M graphics ; INSTAL LDX # >SCROLL ; install P/M "scroll" routine as Immediate LDY #!{iuvax,pur-ee,uunet}!bsu-cs!cfchiesa cfchiesa@bsu-cs.UUCP