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6502Android
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Code Issues Projects Releases Wiki Activity

Implements a few more instructions

This commit is contained in:
Felipe Lima 2015-06-27 17:47:02 -07:00
parent 3c25abc55b
commit 1f4f9278dd
8 changed files with 280 additions and 9 deletions
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14
app/src/main/kotlin/android/emu6502/CPU.kt
View File

@ -44,7 +44,9 @@ class CPU(val memory: Memory) {
Pair(Instruction.BNE, BNE(this)),
Pair(Instruction.JMP, JMP(this)),
Pair(Instruction.JSR, JSR(this)),
Pair(Instruction.RTS, RTS(this))
Pair(Instruction.RTS, RTS(this)),
Pair(Instruction.SEI, SEI(this)),
Pair(Instruction.DEY, DEY(this))
// Pair(Instruction.BPL, BPL(this)),
// Pair(Instruction.BMI, BMI(this)),
// Pair(Instruction.BVC, BVC(this)),
@ -59,7 +61,6 @@ class CPU(val memory: Memory) {
// Pair(Instruction.CLC, CLC(this)),
// Pair(Instruction.SEC, SEC(this)),
// Pair(Instruction.CLI, CLI(this)),
// Pair(Instruction.SEI, SEI(this)),
// Pair(Instruction.CLV, CLV(this)),
// Pair(Instruction.CLD, CLD(this)),
// Pair(Instruction.SED, SED(this)),
@ -69,7 +70,6 @@ class CPU(val memory: Memory) {
// Pair(Instruction.TXA, TXA(this)),
// Pair(Instruction.TAY, TAY(this)),
// Pair(Instruction.TYA, TYA(this)),
// Pair(Instruction.DEY, DEY(this)),
// Pair(Instruction.INY, INY(this)),
// Pair(Instruction.ROR, ROR(this)),
// Pair(Instruction.ROL, ROL(this)),
@ -106,8 +106,8 @@ class CPU(val memory: Memory) {
val function = target.method
target.operation.function()
} else {
Log.e(TAG, "Address $" + PC.toHexString() + " - unknown opcode " + instruction.toHexString())
stop()
throw Exception(
"Address $" + PC.toHexString() + " - unknown opcode " + instruction.toHexString())
}
}
@ -131,6 +131,10 @@ class CPU(val memory: Memory) {
setSVFlagsForValue(X)
}
fun setSZflagsForRegY() {
setSVFlagsForValue(Y)
}
private fun setSVFlagsForValue(value: Int) {
if (value != 0) {
P = P.and(0xfd)

7
app/src/main/kotlin/android/emu6502/instructions/impl/AND.kt
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@ -5,6 +5,9 @@ import android.emu6502.instructions.BaseInstruction
import android.emu6502.instructions.Instruction
/** bitwise AND with accumulator */
class AND(cpu: CPU)
: BaseInstruction(Instruction.AND, cpu.instructionList) {
class AND(private val cpu: CPU) : BaseInstruction(Instruction.AND, cpu.instructionList) {
override fun immediate() {
cpu.A = cpu.A.and(cpu.popByte())
cpu.setSZFlagsForRegA()
}
}

2
app/src/main/kotlin/android/emu6502/instructions/impl/DEX.kt
View File

@ -4,7 +4,7 @@ import android.emu6502.CPU
import android.emu6502.instructions.BaseInstruction
import android.emu6502.instructions.Instruction
/**DEcrement X */
/** DEcrement X */
class DEX(private val cpu: CPU) : BaseInstruction(Instruction.DEX, cpu.instructionList) {
override fun single() {
cpu.X = (cpu.X - 1).and(0xff)

13
app/src/main/kotlin/android/emu6502/instructions/impl/DEY.kt Normal file
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@ -0,0 +1,13 @@
package android.emu6502.instructions.impl
import android.emu6502.CPU
import android.emu6502.instructions.BaseInstruction
import android.emu6502.instructions.Instruction
/** DEcrement Y */
class DEY(private val cpu: CPU) : BaseInstruction(Instruction.DEY, cpu.instructionList) {
override fun single() {
cpu.Y = (cpu.Y - 1).and(0xff)
cpu.setSZflagsForRegY()
}
}

5
app/src/main/kotlin/android/emu6502/instructions/impl/LDA.kt
View File

@ -10,4 +10,9 @@ class LDA(private val cpu: CPU) : BaseInstruction(Instruction.LDA, cpu.instructi
cpu.A = cpu.popByte()
cpu.setSZFlagsForRegA()
}
override fun zeroPage() {
cpu.A = cpu.memory.get(cpu.popByte())
cpu.setSZFlagsForRegA()
}
}

10
app/src/main/kotlin/android/emu6502/instructions/impl/SEI.kt Normal file
View File

@ -0,0 +1,10 @@
package android.emu6502.instructions.impl
import android.emu6502.CPU
import android.emu6502.instructions.BaseInstruction
import android.emu6502.instructions.Instruction
/** SEt Interrupt */
class SEI(private val cpu: CPU) : BaseInstruction(Instruction.SEI, cpu.instructionList) {
}

6
app/src/main/kotlin/android/emu6502/instructions/impl/STA.kt
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@ -10,7 +10,11 @@ class STA(private val memory: Memory, private val cpu: CPU)
: BaseInstruction(Instruction.STA, cpu.instructionList) {
override fun absolute() {
memory.storeByte(cpu.popWord(), cpu.A);
memory.storeByte(cpu.popWord(), cpu.A)
}
override fun zeroPage() {
memory.storeByte(cpu.popByte(), cpu.A)
}
}

232
app/src/test/java/android/emu6502/CPUTest.java
View File

@ -142,4 +142,236 @@ public class CPUTest {
assertThat(cpu.getPC(), equalTo(0x0603));
assertThat(cpu.flags(), equalTo("00110000"));
}
@Test public void testSnake() {
List<String> lines = ImmutableList.of(
"define appleL $00 ; screen location of apple, low byte",
"define appleH $01 ; screen location of apple, high byte",
"define snakeHeadL $10 ; screen location of snake head, low byte",
"define snakeHeadH $11 ; screen location of snake head, high byte",
"define snakeBodyStart $12 ; start of snake body byte pairs",
"define snakeDirection $02 ; direction (possible values are below)",
"define snakeLength $03 ; snake length, in bytes",
"; Directions (each using a separate bit)",
"define movingUp 1",
"define movingRight 2",
"define movingDown 4",
"define movingLeft 8",
"; ASCII values of keys controlling the snake",
"define ASCII_w $77",
"define ASCII_a $61",
"define ASCII_s $73",
"define ASCII_d $64",
"; System variables",
"define sysRandom $fe",
"define sysLastKey $ff",
" jsr init",
" jsr loop",
"init:",
" jsr initSnake",
" jsr generateApplePosition",
" rts",
"initSnake:",
" lda #movingRight ;start direction",
" sta snakeDirection",
" lda #4 ;start length (2 segments)",
" sta snakeLength",
" ",
" lda #$11",
" sta snakeHeadL",
" ",
" lda #$10",
" sta snakeBodyStart",
" ",
" lda #$0f",
" sta $14 ; body segment 1",
" ",
" lda #$04",
" sta snakeHeadH",
" sta $13 ; body segment 1",
" sta $15 ; body segment 2",
" rts",
"generateApplePosition:",
" ;load a new random byte into $00",
" lda sysRandom",
" sta appleL",
" ;load a new random number from 2 to 5 into $01",
" lda sysRandom",
" and #$03 ;mask out lowest 2 bits",
" clc",
" adc #2",
" sta appleH",
" rts",
"loop:",
" jsr readKeys",
" jsr checkCollision",
" jsr updateSnake",
" jsr drawApple",
" jsr drawSnake",
" jsr spinWheels",
" jmp loop",
"readKeys:",
" lda sysLastKey",
" cmp #ASCII_w",
" beq upKey",
" cmp #ASCII_d",
" beq rightKey",
" cmp #ASCII_s",
" beq downKey",
" cmp #ASCII_a",
" beq leftKey",
" rts",
"upKey:",
" lda #movingDown",
" bit snakeDirection",
" bne illegalMove",
" lda #movingUp",
" sta snakeDirection",
" rts",
"rightKey:",
" lda #movingLeft",
" bit snakeDirection",
" bne illegalMove",
" lda #movingRight",
" sta snakeDirection",
" rts",
"downKey:",
" lda #movingUp",
" bit snakeDirection",
" bne illegalMove",
" lda #movingDown",
" sta snakeDirection",
" rts",
"leftKey:",
" lda #movingRight",
" bit snakeDirection",
" bne illegalMove",
" lda #movingLeft",
" sta snakeDirection",
" rts",
"illegalMove:",
" rts",
"checkCollision:",
" jsr checkAppleCollision",
" jsr checkSnakeCollision",
" rts",
"checkAppleCollision:",
" lda appleL",
" cmp snakeHeadL",
" bne doneCheckingAppleCollision",
" lda appleH",
" cmp snakeHeadH",
" bne doneCheckingAppleCollision",
" ;eat apple",
" inc snakeLength",
" inc snakeLength ;increase length",
" jsr generateApplePosition",
"doneCheckingAppleCollision:",
" rts",
"checkSnakeCollision:",
" ldx #2 ;start with second segment",
"snakeCollisionLoop:",
" lda snakeHeadL,x",
" cmp snakeHeadL",
" bne continueCollisionLoop",
"maybeCollided:",
" lda snakeHeadH,x",
" cmp snakeHeadH",
" beq didCollide",
"continueCollisionLoop:",
" inx",
" inx",
" cpx snakeLength ;got to last section with no collision",
" beq didntCollide",
" jmp snakeCollisionLoop",
"didCollide:",
" jmp gameOver",
"didntCollide:",
" rts",
"updateSnake:",
" ldx snakeLength",
" dex",
" txa",
"updateloop:",
" lda snakeHeadL,x",
" sta snakeBodyStart,x",
" dex",
" bpl updateloop",
" lda snakeDirection",
" lsr",
" bcs up",
" lsr",
" bcs right",
" lsr",
" bcs down",
" lsr",
" bcs left",
"up:",
" lda snakeHeadL",
" sec",
" sbc #$20",
" sta snakeHeadL",
" bcc upup",
" rts",
"upup:",
" dec snakeHeadH",
" lda #$1",
" cmp snakeHeadH",
" beq collision",
" rts",
"right:",
" inc snakeHeadL",
" lda #$1f",
" bit snakeHeadL",
" beq collision",
" rts",
"down:",
" lda snakeHeadL",
" clc",
" adc #$20",
" sta snakeHeadL",
" bcs downdown",
" rts",
"downdown:",
" inc snakeHeadH",
" lda #$6",
" cmp snakeHeadH",
" beq collision",
" rts",
"left:",
" dec snakeHeadL",
" lda snakeHeadL",
" and #$1f",
" cmp #$1f",
" beq collision",
" rts",
"collision:",
" jmp gameOver",
"drawApple:",
" ldy #0",
" lda sysRandom",
" sta (appleL),y",
" rts",
"drawSnake:",
" ldx #0",
" lda #1",
" sta (snakeHeadL,x) ; paint head",
" ",
" ldx snakeLength",
" lda #0",
" sta (snakeHeadL,x) ; erase end of tail",
" rts",
"spinWheels:",
" ldx #0",
"spinloop:",
" nop",
" nop",
" dex",
" bne spinloop",
" rts",
"gameOver:", "\n");
assembler.assembleCode(lines);
cpu.execute();
}
}