7c67e867c8
IBM.H is gone, video stuff re-organized. Keyboard stuff reorganized. Machines that have their own video, mouse and/or keyboard now have all this in their machine file. Fixed and other cleanups here and there.
74 lines
2.4 KiB
C
74 lines
2.4 KiB
C
/*
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* 86Box A hypervisor and IBM PC system emulator that specializes in
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* running old operating systems and software designed for IBM
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* PC systems and compatibles from 1981 through fairly recent
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* system designs based on the PCI bus.
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*
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* This file is part of the 86Box distribution.
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*
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* ICS2595 clock chip emulation. Used by ATI Mach64.
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*
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* Version: @(#)vid_ics2595.c 1.0.2 2017/11/04
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*
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* Authors: Sarah Walker, <http://pcem-emulator.co.uk/>
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* Miran Grca, <mgrca8@gmail.com>
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*
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* Copyright 2008-2017 Sarah Walker.
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* Copyright 2016,2017 Miran Grca.
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*/
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#include <stdio.h>
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#include <stdint.h>
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#include <string.h>
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#include <wchar.h>
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#include "../86box.h"
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#include "vid_ics2595.h"
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enum
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{
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ICS2595_IDLE = 0,
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ICS2595_WRITE,
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ICS2595_READ
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};
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static int ics2595_div[4] = {8, 4, 2, 1};
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void ics2595_write(ics2595_t *ics2595, int strobe, int dat)
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{
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if (strobe)
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{
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if ((dat & 8) && !ics2595->oldfs3) /*Data clock*/
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{
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switch (ics2595->state)
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{
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case ICS2595_IDLE:
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ics2595->state = (dat & 4) ? ICS2595_WRITE : ICS2595_IDLE;
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ics2595->pos = 0;
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break;
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case ICS2595_WRITE:
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ics2595->dat = (ics2595->dat >> 1);
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if (dat & 4)
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ics2595->dat |= (1 << 19);
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ics2595->pos++;
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if (ics2595->pos == 20)
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{
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int d, n, l;
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l = (ics2595->dat >> 2) & 0xf;
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n = ((ics2595->dat >> 7) & 255) + 257;
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d = ics2595_div[(ics2595->dat >> 16) & 3];
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ics2595->clocks[l] = (14318181.8 * ((double)n / 46.0)) / (double)d;
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ics2595->state = ICS2595_IDLE;
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}
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break;
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}
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}
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ics2595->oldfs2 = dat & 4;
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ics2595->oldfs3 = dat & 8;
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}
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ics2595->output_clock = ics2595->clocks[dat];
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}
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