SPC8106 S-MOS Systems, SPC8106 Datasheet - Page 362

• Manufacturer Part Number: SPC8106
• Description: LCD/CRT VGA CONTROLLER
• Manufacturer: S-MOS Systems

Programming the Sprite Hardware
UY16-6
// Set the pointer to the start of the odd pixel array
// (512 bytes of Most Significant Bits of color data) and reset the
// display memory pointer. Loop 512 times moving image bytes from the
// image array to display memory.
pImgData = OddArray;
pDisplayMem = A000H:0000;
for (x = 0; x < 512; x++)
/* Restore the upper page swap bit (AUX[9] b0). */
// This step MUST be performed. If not done display data meant for A000h
// segment will be actually written to the B000h segment.
outp (AUX, 9);
outp (AUX + 1, 0);
/* Restore the sequencer index and data. */
// This step only required if the previous step for SPC8108
// use of this code in mode 13h was performed.
outp (SEQ, 4);
outp (SEQ + 1, nSeqDat);
outp (SEQ, nSeqIdx);
/* Set the Sprite Position Registers */
/* --------------------------------- */
// This informs the chip where to find the image in display memory.
// The example image is located in the first 256 bytes in the upper 256k.
// To locate this image set CRTC[36] b0 to 1 and CRTC[37]to 0.
outp (CRTC, 0x36);
outp (CRTC + 1, 1);
outp (CRTC, 0x37);
outp (CRTC, 0);
// For sprites ensure that CRTC[38] b1 is 0 in order to enable the
// four palette colors. For cursors CRTC[38] b1 is set to 1 to enable
// the logical screen/!screen palette. The hardware sprite also supports
// horizontal and vertical doubling based on bits 2 & 3 of this register.
outp (CRTC, 38H);
outp (CRTC +1, 0);
*pDisplayMem++ = *pImgData++;
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// AUX[9] so I will forego a read/mask/write
// and just write blind turning b2 on.
// We don't need them any more.
X12-AN-002-01
// (AND mask for a cursor)
// Select index 9.
// May as well turn them all off.
// Set index 4
// Restore the index 4 data.
// Restore the sequencer index.
// Other image 'slots' will
// require the calculation of
// the offset in which to find
// the image.
// Select CRTC 38H
//
411-1.0
SPC8106