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core, testpico fixes

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kub 2023-06-09 19:22:51 +00:00
parent 3d7abd6905
commit f61d0a4534
3 changed files with 33 additions and 12 deletions
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12
pico/videoport.c
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@ -17,7 +17,8 @@ enum { clkdiv = 2 }; // CPU clock granularity: one of 1,2,4,8
// VDP Slot timing, taken from http://gendev.spritesmind.net/
// forum/viewtopic.php?f=22&t=851&sid=d5701a71396ee7f700c74fb7cd85cb09
// Thank you very much for the great work, Nemesis!
// http://plutiedev.com/mirror/kabuto-hardware-notes
// Thank you very much for the great work, Nemesis, Kabuto!
// Slot clock is sysclock/20 for h32 and sysclock/16 for h40.
// One scanline is 63.7us/63.5us (h32/h40) long which is 488.6/487.4 68k cycles.
@ -30,13 +31,15 @@ enum { slcpu = 488 };
// is generated also depends on the video mode.
enum { hint32 = 0x85, gapstart32 = 0x94, gapend32 = 0xe9};
enum { hint40 = 0xa5, gapstart40 = 0xb7, gapend40 = 0xe5};
// XXX Kabuto says gapend40 is 0xe4, but then a line would've 211 slots, while
// it's 210 in all other sources I looked at?
// The horizontal sync period (HBLANK) is 30/37 slots (h32/h40):
// h32: 4 slots front porch (1.49us), 13 HSYNC (4.84us), 13 back porch (4.84us)
// h40: 5 slots front porch (1.49us), 16 HSYNC (4.77us), 16 back porch (4.77us)
// HBLANK starts in slot 0x93/0xb4, according to Nemesis' measurements.
// HBLANK starts in slot 0x93/0xb3 and ends after slot 0x05 (from Kabuto's doc)
enum { hboff32 = 0x93-hint32, hblen32 = 0xf8-(gapend32-gapstart32)-hint32};//30
enum { hboff40 = 0xb4-hint40, hblen40 = 0xf8-(gapend40-gapstart40)-hint40};//37
enum { hboff40 = 0xb3-hint40, hblen40 = 0xf8-(gapend40-gapstart40)-hint40};//37
// number of slots in a scanline
#define slots32 (0x100-(gapend32-gapstart32)) // 171
@ -1030,7 +1033,8 @@ static u32 VideoSr(const struct PicoVideo *pv)
{
unsigned int hp = pv->reg[12]&1 ? hboff40*488/slots40 : hboff32*488/slots32;
unsigned int hl = pv->reg[12]&1 ? hblen40*488/slots40 : hblen32*488/slots32;
unsigned int c = SekCyclesDone() - Pico.t.m68c_line_start;
// XXX -2 is to please notaz' testpico, but why is this?
unsigned int c = SekCyclesDone()-2 - Pico.t.m68c_line_start;
u32 d;
PicoVideoFIFOSync(c);