SPLIT DISPLAY METHOD FOR CRT SCREEN

摘要

PURPOSE:To improve the availability of a VRAM area and to reduce the CPU time and the memory capacity in a split display method for a CRT screen. CONSTITUTION:The system message to be displayed at A of a CRT screen 1 exists at C2 of a memory 3 as shown in (a). The screen 1 is split in each necessary size for display of C of the memory 3. A part A of the divided screen 1 corresponds to B1 of a VRAM 2. Then B2 of the VRAM 2 which is not corresponding to the screen 1 at the present time point is secured, and C of the memory 3 to be displayed at A of the screen 1 is transferred to the B2 of the VRAM 2 as shown in (b). Then the VRAM area corresponding to A is changed to B2 from B1 of the VRAM 2. The VRAM area corresponding to A of the screen 1 is changed to B1 from B2 of the VRAM 2 after the system message is outputted from an OS as shown in (c).