mhell@mhell.UUCP (Manfred Hell) (05/07/90)
One of my application programs uses a SuperBitMap (1024 pixels hor.) and an associated Screen with 640 pixels wide. This done as described in the common manuals with InitBitMap and AllocRaster. While running the program users can scroll over the total area which is done by the sequence of following functions: Preparation: InitBitMap() using 4 Planes AllocRaster() OpenScreen() using CUSTOMSCREEN, CUSTOMBITMAP amd HIRES OpenWindow() using SUPERBITMAP view=ViewAdress(); rxoffset=&(viewport->RasInfo->RxOffset); the pointer-variable that holds the xoffset for scrolling To scroll i do for instance *rxoffset+=4; MakeScreen(screen); MrgCop(view); LoadView(view); These three functions could be sustituited by ScrollVPort(), but this causes Interrupts to be disabled and I need interrupts running undisturbed. Here's the problem: Doing this sequence repeatedly (for scrolling) display switches from PAL to NTSC and back, that is on screenbottom a black area is blinking hiding parts of the screen. The effect does NOT come up when using Workbench 1.2 or using a display with only 2 Planes! It was verified on different machines with different system-configurations ( with and without PC-Board, Harddisks ). Further i notized, that when screen is in the 'NTSC'-state obviously processor is blocked out from memory- access, because program runs slower. What happens? Where's the mistake? In my programm or in WB1.3 ? Thanks for any hint! -- Manfred Hell ....!cbmehq!cbmger!mhell!mhell