Labels:text | diagram | plan | technical drawing | schematic | font | black and white OCR: Barrel Shifter Function GR3, 63,4 Start Address CRTC reg C&D CPU Write msb CPU Write 8 CPU Read Data 00-7 ALU 8 8 1sb N/A-O None, AND7 OR, XOR Rit 8 *00-O Mask Display 8 Memory D Q GR8 Latch -- Data Rotate GR3, 60-3 - 8 Address- - Set/Reset 0 GRO, 60-3 - Enable Set/Reset 0 GR1, 60-3 - - - Write Mode 8 8 == GR5, 60,1 +CPU Read Plane 1 Latch Data 00-7 - - EGA Functional Diagram Plane 2 Latch - by Bob Montgomery Orlando, Florida Plane 3 Latch - 12-1-87 - * Color Compare 0 8 8 8 GR2, 60-3 8 8 - * Color Don't Care 0 -7 GR7, 60-3 Data from Plane Read Map Data from Plane 2- 7 GR4, 60-2 *= >Extend bit to byte. GR=Graphics Register (3CE, 3CF). Data from Plane 3 Read Mode Each bit gated GR5, 63 Read Map=n selects plane n for reading. Color Don't Care bit n=0 makes color compare ignore plane n. Bit Mask passes Latch data where bits are 0, and switch data where bits are 1.
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