摘要 |
A logic processor-controlled data display apparatus having a display memory in which pixel data representing text for display is stored in bit-map form. The pixel data is produced for each display from character data stored in a background memory. When the character data is stored in bit-map form it can be read directly from the background memory bit-by-bit and written into the display memory as the pixel data. However, this process takes a large number of programme steps, so that the transfer of the data is relatively stow. The present invention provides for the storage in the background memory of character data in the form of machine code sub-routines. The sub-routine for a character contains instructions for identifying the shape-defining pixels (dots) of the character relative to a base dot position and the sub-routine is run to write these pixels into the display memory following location of the base dot position in the display memory.
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