| 摘要 |
PURPOSE:To transfer data from a VRAM to a page buffer without a system bus by providing a data transfer dedicated bus independent of the system bus between the VRAM and a page buffer memory for printer output. CONSTITUTION:A memory controller 9 outputs address and memory control signals required for access to a VRAM 4 to not only the VRAM 4 but also a page buffer memory 6 for printer output and synchronizes the memory control of the page buffer 6 with the VRAM 4 for the purpose of displaying contents of the VRAM 4 on a CRT 5. In this state, a data output bus of the VRAM 4 and a data input bus of the page buffer 6 are connected by a data transfer bus 10. When a write permission signal is outputted to only the buffer 6, contents of the VRAM 4 are displayed on the CRT 5 and are written in the page buffer 6 without using a system bus 2. |
