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Video Memory Test
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Thoroughly tests the on-screen video memory (the memory part that is mapped on to the monitor) of the M64 video board in 8-bit, 16-bit, 32-bit, 64-bit, and 64 byte (block) modes. Entire on screen video memory is tested by testing 512 bit blocks at a time (8x8 pixel block). Each block is tested in two passes. Each pass consists of a data write and read. In the first pass user specified data or random data is used and in the second pass one's complement of the data used in the first pass is used so that each on-screen video memory location (bit) is tested with a zero (electrical low state) and one (electrical high state).
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RAMDAC Test
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Tests the RAMDAC in three phases. In the first phase the RAMDAC CLUT (Color LookUp Table) is tested using simple write/read patterns to determine if there are any bad bits in CLUT.
The data patterns used are:
In the second phase four different patterns are drawn on the screen. Each pattern stays on the screen for approximately three seconds. The four patterns that are drawn are listed below. For each pattern signature is captured and compared with the signature obtained for the same pattern on a known good board. This test verifies that all the different data paths within the RAMDAC are functioning properly.
Patterns drawn on screen:
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Red ramp with cursor at top-left corner of the screen
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Blue ramp with cursor at top-right corner of the screen
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Green ramp with cursor at bottom-left of the screen
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Grey ramp with cursor at bottom-right of the screen
In the last (third) phase of the RAMDAC test the Vertical Retrace Interrupt is tested for 300 interrupts.
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Accelerator Port Test
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Tests all the data paths (sources: fixed color, host data, blit, fixed pattern), arithmetic and logic unit (ALU), color comparator, primitives (destinations: line, rectangle), and mono to color expansion logic. Primitives are drawn using a combination of different data paths (allowed), ALU functions, and color comparator functions. A checksum is generated for each data combination and is compared with the checksum generated for the same data combination on a known good board.
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Table 20-1 m64test Options