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|
{+-----------------------------------------------------------------------------+
| Author: Christian Hackbart
| Description: Mainloop
| Copyright (c) 2000 Christian Hackbart
| Stand: 31.10.2000
|
| http://www.tu-ilmenau.de/~hackbart
+----------------------------------------------------------------------------+}
unit mainloop;
{$MODE objfpc}{$H+}
interface
function z80_decode: byte;
procedure z80_reset;
implementation
uses vars, machine, z80cpu, sound;
procedure TimerControl;
(*
FF05 -- TIMECNT [RW] Timer Counter
This register contains constantly increasing number. The timer
interrupt occurs when this register overflows.
------------------------------------+---------------+---------------
FF07 -- TIMCONT [RW] Timer Control | when set to 1 | when set to 0
Bit2 Start/Stop timer | COUNTING | STOPPED
Bit1-0 Timer clock select:
00 - 4096Hz 01 - 262144Hz 10 - 65536Hz 11 - 16384Hz
------------------------------------+---------------+---------------
BIT: 7 6 5 4 3 2 1 0
value: 128 64 32 16 08 04 02 01
*)
begin
case m_iram[$ff07] and 3 of // Timer clock select
0:
begin
if (c_count >= 1024) then
begin
c_count := 0;
Inc(t_count);
end;
end;
1:
begin
if (c_count >= 16) then
begin
c_count := 0;
Inc(t_count);
end;
end;
2:
begin
if (c_count >= 64) then
begin
c_count := 0;
Inc(t_count);
end;
end;
3:
begin
if (c_count >= 256) then
begin
c_count := 0;
Inc(t_count);
end;
end;
end;
m_iram[$ff05] := Byte(t_count);
if (t_count > 255) then
begin
m_iram[$ff05] := m_iram[$ff06]; // TIMEMOD [RW] Timer Modulo
t_count := m_iram[$ff06];
set_ff0f(4);
end;
end;
procedure LCDControl;
(*
------------------------------------------+---------------+---------------
FF40 -- LCDCONT [RW] LCD Control | when set to 1 | when set to 0
Bit7 LCD operation | ON | OFF
Bit6 Window Tile Table address | 9C00-9FFF | 9800-9BFF
Bit5 Window display | ON | OFF
Bit4 Tile Pattern Table address | 8000-8FFF | 8800-97FF
Bit3 Background Tile Table address | 9C00-9FFF | 9800-9BFF
Bit2 Sprite size | 8x16 | 8x8
Bit1 Color #0 transparency in the window | SOLID | TRANSPARENT
Bit0 Background display | ON | OFF
------------------------------------------+---------------+---------------
*)
var
JI: integer;
begin
{if byte(pchar(cart)[$44]) and $80>0 then exit;}
if (m_iram[$ff40] and 128) = 0 then
begin // LCDCONT=0
make_line_count := -1;
make_line_ccount := 0;
m_iram[$ff41] := m_iram[$ff41] and 252;
nr_t := 0;
cur_c := 3;
cycles := 0;
m_iram[$ff44] := 0;
mode := 5;
cycles := 0;
Inc(vbioff_count);
vbioff_count := vbioff_count mod full_cycles;
if (vbioff_count = 0) then
set_ff0f(1);
end
else // LCDCONT=1
if (cur_c >= cycles) then
begin
cur_c := (cur_c - cycles) mod 4;
old_mode := mode;
Inc(nr_t);
mode := c_tab[nr_t][0];
if (mode = 9) then
begin
mode := 2;
nr_t := 0;
end;
case mode of
2:
begin
make_line_count := -1;
cycles := 82;
m_iram[$ff41] := (m_iram[$ff41] and 252) or 2;
m_iram[$ff44] := c_tab[nr_t][1];
if (m_iram[$ff44] = m_iram[$ff45]) then
begin
m_iram[$ff41] := m_iram[$ff41] or 4;
if (m_iram[$ff41] and 64) > 0 then
set_ff0f(2);
end
else
m_iram[$ff41] := m_iram[$ff41] and 251;
if (m_iram[$ff41] and 32) > 0 then
set_ff0f(2);
end;
3:
begin
make_line_count := 0;
make_line_ccount := cnumber;
if (spriten > 10) then
spriten := 10;
cycles := (175 + 12 * spriten);
m_iram[$ff41] := (m_iram[$ff41] and 252) or 3;
end;
0:
begin
//make_line_finish(m_iram[$ff44]);
make_line_count := -1;
if hdma > 0 then
begin
for ji := 0 to 15 do
begin
spokeb(adr_p, speekb(adr_s));
Inc(adr_p);
Inc(adr_s);
end;
Dec(hdma_count);
m_iram[$ff55] := hdma_count - 1;
if hdma_count = 0 then
begin
hdma := 0;
m_iram[$ff55] := $ff;
end;
end;
cycles := 377 - cycles;
m_iram[$ff41] := m_iram[$ff41] and 252;
if (m_iram[$ff41] and 8) > 0 then
set_ff0f(2);
end;
1:
begin
cycles := 152 * 3;
m_iram[$ff44] := c_tab[nr_t][1];
if (m_iram[$ff44] = m_iram[$ff45]) then
begin
m_iram[$ff41] := m_iram[$ff41] or 4;
if (m_iram[$ff41] and 64) > 0 then
set_ff0f(2);
end
else
m_iram[$ff41] := m_iram[$ff41] and 251;
if ((m_iram[$ff41] and 32 > 0) and (m_iram[$ff40] and 128 > 0)) then
set_ff0f(2);
if (old_mode = 0) then
begin
//make_line_finish(143);
//if (m_iram[$ff40] and 128) > 0 then
//PaintBox.Repaint;
vbi_count := vbi_latency;
end;
make_line_count := -1;
m_iram[$ff41] := (m_iram[$ff41] and 252) or 1;
if (m_iram[$ff41] and 16) > 0 then
set_ff0f(2);
end;
end;
end;
end;
procedure IFlags;
(*
----------------------------------------------+---+---
FF0F -- IFLAGS [RW] Interrupt Flags | 1 | 0
Bit4 Transition High->Low on pins P10-P13 | Y | N
Bit3 End of serial I/O transfer | Y | N
Bit2 Timer overflow | Y | N
Bit1 LCD controller interrupt [see LCDSTAT] | Y | N
Bit0 LCD vertical blanking impulse | Y | N
----------------------------------------------+---+---
*)
begin
gbr_ime := False;
if halt_mode = 1 then
begin
Inc(pc.w);
halt_mode := 0;
end;
push_pc;
if (m_iram[$ff0f] and 16) > 0 then
begin
pc.w := $60;
m_iram[$ff0f] := m_iram[$ff0f] and 239;
end
else
if (m_iram[$ff0f] and 8) > 0 then
begin
pc.w := $58;
m_iram[$ff0f] := m_iram[$ff0f] and 247;
end
else
if (m_iram[$ff0f] and 4) > 0 then
begin
pc.w := $50;
m_iram[$ff0f] := m_iram[$ff0f] and 251;
end
else
if (m_iram[$ff0f] and 2) > 0 then
begin
pc.w := $48;
m_iram[$ff0f] := m_iram[$ff0f] and 253;
end
else
if (m_iram[$ff0f] and 1) > 0 then
begin
pc.w := $40;
m_iram[$ff0f] := m_iram[$ff0f] and 254;
end;
end;
function z80_decode: byte;
var
Count: byte;
begin
if (gbr_ime) and (m_iram[$ff0f] and 31 > 0) then
IFlags; // Start Interupt
pc_old := pc;
code := speekb(pc.w);
Inc(pc.w);
if halt_mode = 2 then
begin
halt_mode := 0;
Dec(pc.w);
end;
if (code = $cb) then
begin
code := speekb(pc.w) or 256;
Inc(pc.w);
end;
Count := z80[code]();
if not WritingVGM then
SoundUpdate(Count * (3 - gb_speed));
cnumber := Count div gb_speed;
if (stop_mode = 1) then
begin
stop_mode := 0;
if ((m_iram[$ff4d]) and 1) > 0 then
begin
if (gb_speed = 1) then
begin
gb_speed := 2;
m_iram[$ff4d] := m_iram[$ff4d] or 128;
end
else
begin
gb_speed := 1;
m_iram[$ff4d] := m_iram[$ff4d] and 127;
end;
end;
end;
if make_line_count >= 0 then
begin
Inc(make_line_ccount, cnumber);
if make_line_ccount >= 8 then
begin
//make_line_tile(m_iram[$ff44], make_line_count);
Inc(make_line_count);
Dec(make_line_ccount, 8);
end;
end;
Inc(cur_c, cnumber);
Inc(n_ff04, cnumber);
if (n_ff04 > 255) then
begin
{$PUSH}{$R-}{$Q-}
Dec(m_iram[$ff04]); // DIVIDER [RW] Divider
{$POP}
// This register is incremented 16384 times
// a second. Writing any value sets it to $00.
n_ff04 := 0;
end;
if (vbi_count <> 9879) then
begin
Dec(vbi_count, cnumber);
if (vbi_count <= 0) then
begin
vbi_count := 9879;
set_ff0f(1);
end;
end;
if (m_iram[$ff07] and 4) > 0 then
Inc(c_count, cnumber); // Start timer
if (halt_mode = 1) then
Dec(pc.w);
case ei_fix of
1:
begin
ei_fix := 0;
gbr_ime := True;
end;
2: Dec(ei_fix);
end;
case di_fix of
1:
begin
di_fix := 0;
gbr_ime := False;
end;
2: Dec(di_fix);
end;
LCDControl;
if ((m_iram[$ff07]) and 4) > 0 then
TimerControl;
if (sio_count > 0) then
begin
m_iram[$ff01] := (m_iram[$ff01] shl 1) or 1; // SIODATA Serial I/O Data
Dec(sio_count);
if sio_count = 0 then
begin
m_iram[$ff02] := m_iram[$ff02] and 127;
set_ff0f(8);
end;
end;
Result := Count;
end;
procedure z80_reset;
var
yrr: byte;
begin
stop_mode := 0;
gb_speed := 1;
vbi_count := 9879;
hdma_count := 0;
hdma := 0;
bc.w := 0;
de.w := $ff56;
hl.w := $d;
pc.w := $100;
sp_.w := $fffe;
af.l := 128;
sio_count := 0;
vbioff_count := 0;
fillchar(m_iram, sizeof(m_iram), 0);
fillchar(m_iram2, sizeof(m_iram2), 0);
fillchar(m_ram, sizeof(m_ram), 0);
fillchar(m_cgbram, sizeof(m_cgbram), 0);
spokeb($ff44, $94);
spokeb($ff01, 0);
spokeb($ff02, $7f);
spokeb($ff04, $af);
spokeb($ff05, 0);
spokeb($ff06, 0);
spokeb($ff07, 0);
spokeb($ff0f, $e1);
{spokeb($ff10, $80);
spokeb($ff11, $bf);
spokeb($ff12, $f3);
spokeb($ff14, $bf);}
spokeb($ff16, $3f);
spokeb($ff17, 0);
spokeb($ff19, $bf);
spokeb($ff1a, $7f);
spokeb($ff1b, $ff);
spokeb($ff1c, $9f);
spokeb($ff1e, $bf);
spokeb($ff20, $ff);
spokeb($ff21, 0);
spokeb($ff22, 0);
spokeb($ff23, $bf);
spokeb($ff24, $77);
spokeb($ff25, $f3);
spokeb($ff26, $f1);
spokeb($ff40, $91);
spokeb($ff41, $81);
spokeb($ff42, 0);
spokeb($ff43, 0);
m_iram[$ff44] := 0;
spokeb($ff45, 0);
spokeb($ff4a, 0);
spokeb($ff4b, 0);
m_iram[$ff4c] := $fe;
m_iram[$ff4d] := $7e;
m_iram[$ff4e] := $ff;
m_iram[$ff4f] := $fe;
m_iram[$ff50] := $fe;
m_iram[$ff51] := 0;
m_iram[$ff52] := 0;
m_iram[$ff53] := 0;
m_iram[$ff54] := 0;
m_iram[$ff55] := $ff;
m_iram[$ff56] := 0;
m_iram[$ff70] := 0;
make_line_count := -1;
make_line_ccount := 0;
addr_bank := 0;
rom_priv := 0;
spokeb($ffff, 0);
di_fix := 0;
ei_fix := 0;
old_mode := 1;
cycles := 1;
machine_cycles := 0; // important for hblank
cur_c := 3;
nr_t := 0;
n_ff04 := 0;
mode := 2;
halt_mode := 0;
gbr_ime := False;
n_ram := 0;
mbc1_type := 0;
c_count := 0;
t_count := 0;
gb_mode := CGB;
spokeb($ff68, 128);
for yrr := 0 to 31 do
begin
spokeb($ff69, $ff);
spokeb($ff69, $7f);
end;
spokeb($ff6a, 128);
spokeb($ff6b, $00);
spokeb($ff6b, $00);
spokeb($ff6b, $27);
spokeb($ff6b, $AF);
spokeb($ff6b, $81);
spokeb($ff6b, $49);
spokeb($ff6b, $E9);
spokeb($ff6b, $3C);
spokeb($ff6b, $AC);
spokeb($ff6b, $28);
spokeb($ff6b, $53);
spokeb($ff6b, $FE);
spokeb($ff6b, $81);
spokeb($ff6b, $51);
spokeb($ff6b, $7D);
spokeb($ff6b, $67);
spokeb($ff6b, $04);
spokeb($ff6b, $04);
spokeb($ff6b, $DF);
spokeb($ff6b, $BF);
spokeb($ff6b, $09);
spokeb($ff6b, $01);
spokeb($ff6b, $EF);
spokeb($ff6b, $FF);
spokeb($ff6b, $0C);
spokeb($ff6b, $03);
spokeb($ff6b, $FC);
spokeb($ff6b, $77);
spokeb($ff6b, $08);
spokeb($ff6b, $69);
spokeb($ff6b, $FE);
spokeb($ff6b, $DB);
spokeb($ff6b, $0C);
spokeb($ff6b, $84);
spokeb($ff6b, $E9);
spokeb($ff6b, $7F);
spokeb($ff6b, $0C);
spokeb($ff6b, $61);
spokeb($ff6b, $1F);
spokeb($ff6b, $DF);
spokeb($ff6b, $00);
spokeb($ff6b, $80);
spokeb($ff6b, $7E);
spokeb($ff6b, $7E);
spokeb($ff6b, $04);
spokeb($ff6b, $80);
spokeb($ff6b, $58);
spokeb($ff6b, $76);
spokeb($ff6b, $9B);
spokeb($ff6b, $9C);
spokeb($ff6b, $C3);
spokeb($ff6b, $D6);
spokeb($ff6b, $12);
spokeb($ff6b, $4C);
spokeb($ff6b, $CD);
spokeb($ff6b, $EC);
spokeb($ff6b, $3B);
spokeb($ff6b, $26);
spokeb($ff6b, $7B);
spokeb($ff6b, $FA);
spokeb($ff6b, $88);
spokeb($ff6b, $48);
spokeb($ff6b, $FF);
spokeb($ff6b, $F2);
spokeb($ff47, $fc);
spokeb($ff48, $ff);
spokeb($ff49, $ff);
if cart <> nil then
if (PChar(cart)[$143] in [#$80, #$c0]) then
begin
af.h := $11;
gb_mode := CGB;
end
else
begin
af.h := 1;
gb_mode := DMG;
end;
end;
end.
|
