split DoubleScrunch into two
This commit is contained in:
Denis Molony
parent
e4ed878f69
commit
080976fc48
|
|
@ -1,39 +1,21 @@
|
|||
package com.bytezone.diskbrowser.applefile;
|
||||
|
||||
import com.bytezone.diskbrowser.utilities.CPU;
|
||||
|
||||
public class DoubleScrunch extends CPU
|
||||
// -----------------------------------------------------------------------------------//
|
||||
public class DoubleScrunch
|
||||
// -----------------------------------------------------------------------------------//
|
||||
{
|
||||
private byte mem_71D0; // varies 1/0/1/0 ...
|
||||
private byte mem_71D2; // column index * 2 (00-4F) increments every C0 bytes
|
||||
private byte mem_71D3; // byte to repeat
|
||||
private byte mem_71D4; // repetition counter
|
||||
|
||||
private int src; // base address of packed buffer
|
||||
private int dst; // base address of main/aux memory
|
||||
|
||||
private byte zp_00; // input buffer offset
|
||||
private byte zp_01;
|
||||
|
||||
private byte zp_26; // output buffer offset
|
||||
private byte zp_27;
|
||||
|
||||
private byte zp_E6; // hi-res page ($20 or $40)
|
||||
|
||||
// final byte[] auxBuffer = new byte[0x2000];
|
||||
// final byte[] primaryBuffer = new byte[0x2000];
|
||||
final byte[][] memory = new byte[2][0x2000];
|
||||
private byte[] packedBuffer;
|
||||
|
||||
// private final boolean debug = false;
|
||||
private int count;
|
||||
private final int[] rows = new int[192];
|
||||
private int ptr;
|
||||
private int bank;
|
||||
private int outPtr;
|
||||
private int column;
|
||||
|
||||
public DoubleScrunch ()
|
||||
// ---------------------------------------------------------------------------------//
|
||||
public DoubleScrunch (byte[] buffer)
|
||||
// ---------------------------------------------------------------------------------//
|
||||
{
|
||||
int row = 0;
|
||||
|
||||
|
|
@ -42,34 +24,33 @@ public class DoubleScrunch extends CPU
|
|||
for (int c = 0; c < 0x400; c += 0x80)
|
||||
for (int d = 0; d < 0x2000; d += 0x800)
|
||||
rows[row++] = a + b + c + d;
|
||||
}
|
||||
|
||||
void unscrunch (byte[] buffer)
|
||||
{
|
||||
packedBuffer = buffer;
|
||||
|
||||
while (true)
|
||||
{
|
||||
int rep = packedBuffer[ptr++] & 0xFF;
|
||||
int repeat = packedBuffer[ptr++] & 0xFF;
|
||||
|
||||
if ((rep & 0x80) == 0) // repeat same byte
|
||||
if ((repeat & 0x80) == 0) // repeat same byte
|
||||
{
|
||||
byte val = packedBuffer[ptr++];
|
||||
while (rep-- > 0)
|
||||
while (repeat-- > 0)
|
||||
if (move (val))
|
||||
return;
|
||||
}
|
||||
else // copy bytes
|
||||
{
|
||||
rep &= 0x7F;
|
||||
while (rep-- > 0)
|
||||
repeat &= 0x7F;
|
||||
while (repeat-- > 0)
|
||||
if (move (packedBuffer[ptr++]))
|
||||
return;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// ---------------------------------------------------------------------------------//
|
||||
private boolean move (byte val)
|
||||
// ---------------------------------------------------------------------------------//
|
||||
{
|
||||
memory[bank][rows[outPtr++] + column] = val;
|
||||
|
||||
|
|
@ -85,208 +66,4 @@ public class DoubleScrunch extends CPU
|
|||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
// no longer needed, it was used to decipher the Beagle Bros routine
|
||||
void oldUnscrunch (byte[] buffer)
|
||||
{
|
||||
packedBuffer = buffer;
|
||||
|
||||
src = 0x4000; // packed picture data
|
||||
dst = 0x2000; // main/aux picture data
|
||||
|
||||
zp_00 = 0x00; // load address of packed buffer
|
||||
zp_01 = 0x40;
|
||||
|
||||
zp_E6 = 0x20; // hi-res page 1
|
||||
|
||||
lda (zp_E6);
|
||||
ora ((byte) 0x04);
|
||||
zp_27 = sta ();
|
||||
|
||||
ldx ((byte) 0x01);
|
||||
mem_71D0 = stx (); // X and 71D0 are both set to 1
|
||||
|
||||
ldy ((byte) 0x00);
|
||||
mem_71D2 = sty (); // column index = 0
|
||||
zp_26 = sty (); // output index = 0
|
||||
|
||||
while (true)
|
||||
{
|
||||
// get the repetition counter (hi-bit is a flag to indicate copy/repeat)
|
||||
lda (packedBuffer, indirectY (src, zp_00, zp_01)); // LDA ($00),Y)
|
||||
|
||||
php ();
|
||||
|
||||
// increment address to get next transfer byte (done in copy/repeat routine)
|
||||
zp_00 = inc (zp_00);
|
||||
if (zero)
|
||||
zp_01 = inc (zp_01);
|
||||
|
||||
and ((byte) 0x7F); // remove copy/repeat flag
|
||||
mem_71D4 = sta (); // save repetition counter (RC)
|
||||
plp ();
|
||||
|
||||
// copy or repeat RC bytes
|
||||
if (negative ? copyBytes () : repeatBytes ())
|
||||
break;
|
||||
|
||||
// increment address to get next repetition counter
|
||||
zp_00 = inc (zp_00);
|
||||
if (zero)
|
||||
zp_01 = inc (zp_01);
|
||||
}
|
||||
}
|
||||
|
||||
// copy a single byte RC times
|
||||
private boolean repeatBytes ()
|
||||
{
|
||||
// get the byte to store
|
||||
lda (packedBuffer, indirectY (src, zp_00, zp_01)); // LDA ($00),Y)
|
||||
mem_71D3 = sta ();
|
||||
|
||||
while (true)
|
||||
{
|
||||
lda (mem_71D3); // get the byte to store
|
||||
|
||||
storeByte (); // store it and decrement repetition counter
|
||||
|
||||
calculateScreenColumn ();
|
||||
if (carry)
|
||||
return true; // completely finished
|
||||
|
||||
calculateNextScreenAddress ();
|
||||
|
||||
ldy (mem_71D4); // check the repetition counter
|
||||
if (zero)
|
||||
return false; // not finished
|
||||
}
|
||||
}
|
||||
|
||||
// copy the next RC bytes
|
||||
private boolean copyBytes ()
|
||||
{
|
||||
while (true)
|
||||
{
|
||||
// get the byte to store
|
||||
ldy ((byte) 0x00);
|
||||
lda (packedBuffer, indirectY (src, zp_00, zp_01)); // LDA ($00),Y)
|
||||
|
||||
storeByte (); // store it and decrement repetition counter
|
||||
|
||||
calculateScreenColumn ();
|
||||
if (carry)
|
||||
return true; // completely finished
|
||||
|
||||
calculateNextScreenAddress ();
|
||||
|
||||
ldy (mem_71D4); // check the repetition counter
|
||||
if (zero)
|
||||
return false; // not finished
|
||||
|
||||
// prepare address for next read
|
||||
zp_00 = inc (zp_00);
|
||||
if (zero)
|
||||
zp_01 = inc (zp_01);
|
||||
}
|
||||
}
|
||||
|
||||
// store the byte currently in Acc
|
||||
private void storeByte ()
|
||||
{
|
||||
mem_71D4 = dec (mem_71D4); // decrement repetition counter (RC)
|
||||
ldy (mem_71D2); // column index (times 2)
|
||||
|
||||
php ();
|
||||
// sei ();
|
||||
pha ();
|
||||
tya ();
|
||||
lsr (); // divide by 2, put odd/even value in carry (bank)
|
||||
tay ();
|
||||
pla ();
|
||||
|
||||
// store byte
|
||||
if (false)
|
||||
System.out.printf (
|
||||
"%04X D0: %02X D2: %02X xReg: %02X bank: %d %02X -> %02X %02X + %02X%n",
|
||||
count++, mem_71D0, mem_71D2, stx (), carry ? 0 : 1, sta (), zp_27, zp_26,
|
||||
sty ());
|
||||
sta (memory[carry ? 1 : 0], indirectY (dst, zp_26, zp_27));
|
||||
|
||||
plp ();
|
||||
}
|
||||
|
||||
// $71B1
|
||||
private void calculateScreenColumn ()
|
||||
{
|
||||
// increment X by 2 - X varies 01, 03, 05 -> BF, then 00, 02, 04 -> BE
|
||||
inx ();
|
||||
inx ();
|
||||
cpx ((byte) 0xC0); // # screen lines
|
||||
if (!carry) // X < $C0
|
||||
return; // continue current phase
|
||||
|
||||
// carry is now set, current phase is finished
|
||||
|
||||
// change phase
|
||||
mem_71D0 = dec (mem_71D0); // either 1 -> 0, or 0 -> -1
|
||||
if (!negative) //
|
||||
{
|
||||
assert mem_71D0 == 0;
|
||||
// start second phase of screen column
|
||||
ldx ((byte) 0x00); // start X at 0
|
||||
// mem_71D0 = stx (); // phase 2 (not necessary, was already 0)
|
||||
clc ();
|
||||
return; // start phase 2
|
||||
}
|
||||
|
||||
// start a new screen column (and start phase 1)
|
||||
mem_71D2 = inc (mem_71D2); // increment column index
|
||||
ldy (mem_71D2);
|
||||
cpy ((byte) 0x50); // test for end of line (2 x 0x28)
|
||||
if (carry) // Y >= $50
|
||||
return; // program finished
|
||||
|
||||
ldx ((byte) 0x01); // start X at 1
|
||||
mem_71D0 = stx (); // start phase 1
|
||||
clc ();
|
||||
}
|
||||
|
||||
// set locations $26-27 (address of first location in screen line)
|
||||
private void calculateNextScreenAddress ()
|
||||
{
|
||||
txa ();
|
||||
and ((byte) 0xC0); // get 2 hi bits - 00/40/80
|
||||
zp_26 = sta ();
|
||||
|
||||
lsr ();
|
||||
lsr ();
|
||||
ora (zp_26); // graphics page ($20 or $40)
|
||||
zp_26 = sta ();
|
||||
|
||||
txa ();
|
||||
zp_27 = sta ();
|
||||
|
||||
asl ();
|
||||
asl ();
|
||||
asl ();
|
||||
zp_27 = rol (zp_27);
|
||||
|
||||
asl ();
|
||||
zp_27 = rol (zp_27);
|
||||
|
||||
asl ();
|
||||
zp_26 = ror (zp_26);
|
||||
|
||||
lda (zp_27);
|
||||
and ((byte) 0x1F); // clear bits 7-5
|
||||
ora (zp_E6); // graphics page ($20 or $40)
|
||||
zp_27 = sta ();
|
||||
}
|
||||
|
||||
@Override
|
||||
protected String debugString ()
|
||||
{
|
||||
return String.format ("0: %02X %02X 26: %02X %02X %02X %02X %02X %02X", zp_00,
|
||||
zp_01, zp_26, zp_27, mem_71D0, mem_71D2, mem_71D3, mem_71D4);
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,246 @@
|
|||
package com.bytezone.diskbrowser.applefile;
|
||||
|
||||
import com.bytezone.diskbrowser.utilities.CPU;
|
||||
|
||||
// -----------------------------------------------------------------------------------//
|
||||
public class DoubleScrunchCPU extends CPU
|
||||
// -----------------------------------------------------------------------------------//
|
||||
{
|
||||
private byte mem_71D0; // varies 1/0/1/0 ...
|
||||
private byte mem_71D2; // column index * 2 (00-4F) increments every C0 bytes
|
||||
private byte mem_71D3; // byte to repeat
|
||||
private byte mem_71D4; // repetition counter
|
||||
|
||||
private int src; // base address of packed buffer
|
||||
private int dst; // base address of main/aux memory
|
||||
|
||||
private byte zp_00; // input buffer offset
|
||||
private byte zp_01;
|
||||
|
||||
private byte zp_26; // output buffer offset
|
||||
private byte zp_27;
|
||||
|
||||
private byte zp_E6; // hi-res page ($20 or $40)
|
||||
|
||||
final byte[][] memory = new byte[2][0x2000];
|
||||
private byte[] packedBuffer;
|
||||
|
||||
private int count;
|
||||
|
||||
// ---------------------------------------------------------------------------------//
|
||||
void unscrunch (byte[] buffer)
|
||||
// ---------------------------------------------------------------------------------//
|
||||
{
|
||||
packedBuffer = buffer;
|
||||
|
||||
src = 0x4000; // packed picture data
|
||||
dst = 0x2000; // main/aux picture data
|
||||
|
||||
zp_00 = 0x00; // load address of packed buffer
|
||||
zp_01 = 0x40;
|
||||
|
||||
zp_E6 = 0x20; // hi-res page 1
|
||||
|
||||
lda (zp_E6);
|
||||
ora ((byte) 0x04);
|
||||
zp_27 = sta ();
|
||||
|
||||
ldx ((byte) 0x01);
|
||||
mem_71D0 = stx (); // X and 71D0 are both set to 1
|
||||
|
||||
ldy ((byte) 0x00);
|
||||
mem_71D2 = sty (); // column index = 0
|
||||
zp_26 = sty (); // output index = 0
|
||||
|
||||
while (true)
|
||||
{
|
||||
// get the repetition counter (hi-bit is a flag to indicate copy/repeat)
|
||||
lda (packedBuffer, indirectY (src, zp_00, zp_01)); // LDA ($00),Y)
|
||||
|
||||
php ();
|
||||
|
||||
// increment address to get next transfer byte (done in copy/repeat routine)
|
||||
zp_00 = inc (zp_00);
|
||||
if (zero)
|
||||
zp_01 = inc (zp_01);
|
||||
|
||||
and ((byte) 0x7F); // remove copy/repeat flag
|
||||
mem_71D4 = sta (); // save repetition counter (RC)
|
||||
plp ();
|
||||
|
||||
// copy or repeat RC bytes
|
||||
if (negative ? copyBytes () : repeatBytes ())
|
||||
break;
|
||||
|
||||
// increment address to get next repetition counter
|
||||
zp_00 = inc (zp_00);
|
||||
if (zero)
|
||||
zp_01 = inc (zp_01);
|
||||
}
|
||||
}
|
||||
|
||||
// copy a single byte RC times
|
||||
// ---------------------------------------------------------------------------------//
|
||||
private boolean repeatBytes ()
|
||||
// ---------------------------------------------------------------------------------//
|
||||
{
|
||||
// get the byte to store
|
||||
lda (packedBuffer, indirectY (src, zp_00, zp_01)); // LDA ($00),Y)
|
||||
mem_71D3 = sta ();
|
||||
|
||||
while (true)
|
||||
{
|
||||
lda (mem_71D3); // get the byte to store
|
||||
|
||||
storeByte (); // store it and decrement repetition counter
|
||||
|
||||
calculateScreenColumn ();
|
||||
if (carry)
|
||||
return true; // completely finished
|
||||
|
||||
calculateNextScreenAddress ();
|
||||
|
||||
ldy (mem_71D4); // check the repetition counter
|
||||
if (zero)
|
||||
return false; // not finished
|
||||
}
|
||||
}
|
||||
|
||||
// copy the next RC bytes
|
||||
// ---------------------------------------------------------------------------------//
|
||||
private boolean copyBytes ()
|
||||
// ---------------------------------------------------------------------------------//
|
||||
{
|
||||
while (true)
|
||||
{
|
||||
// get the byte to store
|
||||
ldy ((byte) 0x00);
|
||||
lda (packedBuffer, indirectY (src, zp_00, zp_01)); // LDA ($00),Y)
|
||||
|
||||
storeByte (); // store it and decrement repetition counter
|
||||
|
||||
calculateScreenColumn ();
|
||||
if (carry)
|
||||
return true; // completely finished
|
||||
|
||||
calculateNextScreenAddress ();
|
||||
|
||||
ldy (mem_71D4); // check the repetition counter
|
||||
if (zero)
|
||||
return false; // not finished
|
||||
|
||||
// prepare address for next read
|
||||
zp_00 = inc (zp_00);
|
||||
if (zero)
|
||||
zp_01 = inc (zp_01);
|
||||
}
|
||||
}
|
||||
|
||||
// store the byte currently in Acc
|
||||
// ---------------------------------------------------------------------------------//
|
||||
private void storeByte ()
|
||||
// ---------------------------------------------------------------------------------//
|
||||
{
|
||||
mem_71D4 = dec (mem_71D4); // decrement repetition counter (RC)
|
||||
ldy (mem_71D2); // column index (times 2)
|
||||
|
||||
php ();
|
||||
// sei ();
|
||||
pha ();
|
||||
tya ();
|
||||
lsr (); // divide by 2, put odd/even value in carry (bank)
|
||||
tay ();
|
||||
pla ();
|
||||
|
||||
if (false)
|
||||
System.out.printf (
|
||||
"%04X D0: %02X D2: %02X xReg: %02X bank: %d %02X -> %02X %02X + %02X%n",
|
||||
count++, mem_71D0, mem_71D2, stx (), carry ? 0 : 1, sta (), zp_27, zp_26,
|
||||
sty ());
|
||||
|
||||
// store byte
|
||||
sta (memory[carry ? 1 : 0], indirectY (dst, zp_26, zp_27));
|
||||
plp ();
|
||||
}
|
||||
|
||||
// $71B1
|
||||
// ---------------------------------------------------------------------------------//
|
||||
private void calculateScreenColumn ()
|
||||
// ---------------------------------------------------------------------------------//
|
||||
{
|
||||
// increment X by 2 - X varies 01, 03, 05 -> BF, then 00, 02, 04 -> BE
|
||||
inx ();
|
||||
inx ();
|
||||
cpx ((byte) 0xC0); // # screen lines
|
||||
if (!carry) // X < $C0
|
||||
return; // continue current phase
|
||||
|
||||
// carry is now set, current phase is finished
|
||||
|
||||
// change phase
|
||||
mem_71D0 = dec (mem_71D0); // either 1 -> 0, or 0 -> -1
|
||||
if (!negative) //
|
||||
{
|
||||
assert mem_71D0 == 0;
|
||||
// start second phase of screen column
|
||||
ldx ((byte) 0x00); // start X at 0
|
||||
// mem_71D0 = stx (); // phase 2 (not necessary, was already 0)
|
||||
clc ();
|
||||
return; // start phase 2
|
||||
}
|
||||
|
||||
// start a new screen column (and start phase 1)
|
||||
mem_71D2 = inc (mem_71D2); // increment column index
|
||||
ldy (mem_71D2);
|
||||
cpy ((byte) 0x50); // test for end of line (2 x 0x28)
|
||||
if (carry) // Y >= $50
|
||||
return; // program finished
|
||||
|
||||
ldx ((byte) 0x01); // start X at 1
|
||||
mem_71D0 = stx (); // start phase 1
|
||||
clc ();
|
||||
}
|
||||
|
||||
// set locations $26-27 (address of first location in screen line)
|
||||
// ---------------------------------------------------------------------------------//
|
||||
private void calculateNextScreenAddress ()
|
||||
// ---------------------------------------------------------------------------------//
|
||||
{
|
||||
txa ();
|
||||
and ((byte) 0xC0); // get 2 hi bits - 00/40/80
|
||||
zp_26 = sta ();
|
||||
|
||||
lsr ();
|
||||
lsr ();
|
||||
ora (zp_26); // graphics page ($20 or $40)
|
||||
zp_26 = sta ();
|
||||
|
||||
txa ();
|
||||
zp_27 = sta ();
|
||||
|
||||
asl ();
|
||||
asl ();
|
||||
asl ();
|
||||
zp_27 = rol (zp_27);
|
||||
|
||||
asl ();
|
||||
zp_27 = rol (zp_27);
|
||||
|
||||
asl ();
|
||||
zp_26 = ror (zp_26);
|
||||
|
||||
lda (zp_27);
|
||||
and ((byte) 0x1F); // clear bits 7-5
|
||||
ora (zp_E6); // graphics page ($20 or $40)
|
||||
zp_27 = sta ();
|
||||
}
|
||||
|
||||
// ---------------------------------------------------------------------------------//
|
||||
@Override
|
||||
protected String debugString ()
|
||||
// ---------------------------------------------------------------------------------//
|
||||
{
|
||||
return String.format ("0: %02X %02X 26: %02X %02X %02X %02X %02X %02X", zp_00,
|
||||
zp_01, zp_26, zp_27, mem_71D0, mem_71D2, mem_71D3, mem_71D4);
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue