Peritek VCD-V, User Manual

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Peritek
Installing Your Peritek Graphics Board 2-17
Table 2-4 DRAM Size Jumpers
D1 D0 DRAM Size
0 0 1 or 4 MB
0 1 8 MB
1 0 16 MB
1 1 32 MB
Table 2-5 VRAM Size Jumpers
V1 V0 VCD-V & VCT-V
VRAM Size
VCU-V VRAM Size
0 0 1 page 2 page
0 1 2 pages 4 pages
1 0 4 pages 8 pages
1 1 4 pages 8 pages
2.4.7 Master Pixel Clock Oscillator Frequency
VCU-V and VCT-V
VCU-V and VCT-V boards have a software programmable pixel clock,
which allows virtually any frequency pixel clock to be chosen. Peritek
distributes an number of standard initialization tables, and can provide
custom versions upon request. See Section 5.4 for more information
The VCU-V uses the ICS1562 clock chip, which actually gives a
maximum pixel clock in excess of 200 MHz. Note that the BT468 color
map chip must be upgraded from its standard 170 MHz to take advantage
of this.
The VCT-V uses either the ICS1562 or the ICS1572 (in some special
configurations). The ICS1572 has a 150 MHz maximum clock frequency,
which is more than what the BT463 color map chip is limited to (135
MHz). The 1562 and 1572 take exactly the same program parameters.