root@yale.UUCP (Celray Stalk) (10/06/88)
I just got a Mega-4 and am having a problem with the blitter chip. With the blitter turned off, everything is fine. With it on, partial "shadows" of the window border get left behind when I drag a window across the screen with the mouse. These are little vertical lines of random height running up from where the bottom of the window was as it was being moved. It looks as if the CPU is not synchronizing itself properly with the blitter chip, perhaps aborting a blit in the middle. The problem occurs with both TOS 1.2 (the Mega ROM) and the new Developer's version of TOS 1.4. Has anybody seen this problem before? Do I have a bad blitter chip, or is the problem systemic with all Mega's? ================================================== | Michael Fischer | | Arpanet: <fischer-michael@cs.yale.edu> | | Bitnet: <fischer-michael@yalecs.bitnet> | | UUCP: <fischer-michael@yale.UUCP> | ==================================================
jgj@hcx2.SSD.HARRIS.COM (10/07/88)
> With the blitter turned off, everything is fine. With it on, partial >"shadows" of the window border get left behind when I drag a window >across the screen with the mouse. These are little vertical lines of By any chance, are you running one of those clock accessories that put the time in the upper right hand corner? I observed the same thing, but only when that clock accessory is installed. I suspect it involves a reentrency problem with the routines. The accessory performs (I assume) a-line operations from interupt level and the code that handles the hardware blitter gets confused when it gets to many pending requests. Atari, can you say "semaphore"? Realize that this is a guess. Since the fastest speed up I have ever clocked the blitter to have was about 5%, Just turn the blitter off and forget it was ever there. ============================================================================ Jeffrey Glen Jackson | Satan jeered, "You're dead meat Jesus, I'm gonna jgj@ssd.harris.com | bust you up tonight." | Jesus said, "Go ahead, make my day." | -- Carman, "The Champion"
root@yale.UUCP (Celray Stalk) (10/09/88)
In article <46700013@hcx2> jgj@hcx2.SSD.HARRIS.COM writes: > >> With the blitter turned off, everything is fine. With it on, partial >>"shadows" of the window border get left behind when I drag a window >>across the screen with the mouse. These are little vertical lines of > >By any chance, are you running one of those clock accessories that put the >time in the upper right hand corner? Yes, I was! I just deistalled it and the problem went away. Thank you very much for your help. ================================================== | Michael Fischer | | Arpanet: <fischer-michael@cs.yale.edu> | | Bitnet: <fischer-michael@yalecs.bitnet> | | UUCP: <fischer-michael@yale.UUCP> | ==================================================