tmerritt/mos6502
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

improved matrix display stuff

Browse Source
This commit is contained in:
Trevor Merritt 2025-07-03 09:29:46 -04:00
parent 1a53f1d782
commit 8509b20109
6 changed files with 356 additions and 109 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
beneater/src/parts/ben_eater_pc.rs
View File

@ -23,7 +23,7 @@ impl BenEaterPC {
}
pub fn tick_system(&mut self) {
let (address, data, rw) = self.cpu.tick();
self.cpu.tick();
if self.cpu.microcode_step == 0 {
// tick the clock.
// tick the memory

159
beneater/src/parts/display_matrix.rs
View File

@ -1,6 +1,14 @@
use macroquad::prelude::*;
use crate::parts::address_bus::AddressBus;
use crate::parts::data_bus::DataBus;
use crate::parts::display_matrix::MatrixEntryMode::{Delete, DeleteShift, Insert, InsertShift};
pub enum MatrixEntryMode {
Delete,
DeleteShift,
Insert,
InsertShift,
}
pub struct DisplayMatrix {
width: f32,
@ -9,42 +17,138 @@ pub struct DisplayMatrix {
data_bus: DataBus,
rs: bool,
rw: bool,
cursor_position: u8
cursor_position: u8,
busy: bool,
entry_mode: MatrixEntryMode,
cursor: bool,
on: bool,
blink: bool,
cursor_shift: bool,
display_shift: bool,
enabled: bool,
}
impl DisplayMatrix {
pub fn set_bus(&mut self, rs: bool, rw: bool, bus: u8, e: bool) {
self.rs = rs;
self.rw = rw;
self.data_bus.data = bus;
self.enabled = e;
}
/// Reset the Display to its 'factory boot' state
pub fn reset(&mut self) {
// 1. Display clear
self.set_bus(false, false, 0b0000_0001, true);
self.tick(false, false, true, 0b0000_0001);
// Function Set
// DL = 1; 8-bit interface data
// N = 0; 1-line display
// F = 0; 5 × 8 dot character font
self.tick(false, false, true, 0b0011_0000);;
// 3. Display on/off control:
// D = 0; Display off
// C = 0; Cursor off
// B = 0; Blinking off
self.tick(false, false, true, 0b0000_1000);
// 4. Entry mode set:
// I/D = 1; Increment by 1
// S = 0; No shift
self.tick(false, false,true, 0b0000_0110);
self.busy = false;
}
pub fn new(width: f32, height: f32) -> DisplayMatrix {
DisplayMatrix {
let mut matrix = DisplayMatrix {
width,
height,
text_buffer: String::from(""),
data_bus: DataBus::new(),
rs: false,
rw: false,
cursor_position: 0x00
}
cursor_position: 0x00,
busy: false,
entry_mode: MatrixEntryMode::InsertShift,
on: false,
cursor: false,
blink: false,
cursor_shift: false,
display_shift: false,
enabled: false,
};
matrix
}
/// Tick
///
/// Checks the data bus and sees what the setup is.
///
/// 0 0 0 0 0 0 0 1 -> Clear Display
/// 0 0 0 0 0 0 1 - -> Return Home
/// 0 0 0 0 0 0 A B -> Sets cursor move direction and shift
/// A -> 0 = Insert, 1 = Delete
/// B -> Scroll bool
/// 0 0 0 0 1 D C B -> Sets display mode
/// D -> Display On/Off
/// C -> Cursor On/Off
/// B -> Blink
pub fn tick(&mut self) {
pub fn tick(&mut self, rw: bool, rs: bool, enabled: bool, data: u8) {
self.enabled = enabled;
self.data_bus.data = data;
self.rw = rw;
self.rs = rs;
// parse whats on the data bus.
match (self.rs, self.rw) {
(true, true) => {
// read from cg or ddram
}
(true, false) => {
// write to cg or ddram
println!("WRITE TO CG/DD RAM -> {:08b} / {:02x} / {}", self.data_bus.data, self.data_bus.data, self.data_bus.data);
}
(false, true) => {
// read the busy flag.
self.data_bus.data = (self.busy as u8) << 7 | (self.cursor_position & 0x7F);
self.enabled = true;
}
(false, false) => {
match self.data_bus.data {
0b0000_0001 => {
// clear display
self.text_buffer = " ".repeat(32);
}
0b0000_0010..=0b0000_0011 => {
// return home
self.cursor_position = 0x00;
}
0b0000_0100..=0b0000_0111 => {
self.entry_mode = match self.data_bus.data {
0b01 => DeleteShift,
0b10 => Insert,
0b11 => InsertShift,
_ => {
// Default mode
Delete
}
};
}
0b0000_1000..=0b0000_1111 => {
// display control
self.on = self.data_bus.data & 0b100 == 0b100;
self.cursor = self.data_bus.data & 0b10 == 0b10;
self.blink = self.data_bus.data & 0b1 == 0b1;
}
0b0001_0000..=0b0001_1111 => {
// cursor control
self.cursor_shift = self.data_bus.data & 0b1000 == 0b1000;
self.display_shift = self.data_bus.data & 0b100 == 0b100;
}
0b0010_0000..=0b0011_1111 => {
// function set
println!("Ignoring function set. this is going to play like an 8bit 2 row");
}
0b0100_0000..=0b0111_1111 => {
// set CGRam Address
println!("Ignoring set CGRam Address. Not Changing how the characters are displayed.");
}
0b1000_0000..=0b1111_1111 => {
// set DDRam address
self.cursor_position = self.data_bus.data & 0b0111_1111;
}
_ => {
// Invalid Command
}
}
}
}
pub fn set_busses(&mut self, address_bus: &mut AddressBus, data_bus: &mut DataBus) {
}
pub fn push_letter(&mut self, letter_to_push: char) {
@ -77,3 +181,16 @@ impl DisplayMatrix {
draw_line(x2, y1, x2, y2, 1.0, color);
}
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn smoke() { assert!(true); }
#[test]
fn device_init() {
let display = DisplayMatrix::new(100.0, 100.0);
}
}

9
core/src/instruction_table.rs
View File

@ -4,6 +4,15 @@ use crate::op_info::OpInfo;
use crate::operation::Operation;
use crate::operation::Operation::*;
pub fn INSTRUCTION_CYCLES(instruction: u8) -> u8 {
INSTRUCTION_TABLE[instruction as usize].unwrap().cycles
}
pub fn INSTRUCTION_LENGTH(instruction: u8) -> u8 {
INSTRUCTION_TABLE[instruction as usize].unwrap().length
}
pub const INSTRUCTION_TABLE: [Option<OpInfo>; 256] = {
let mut table: [Option<OpInfo>; 256] = [const { None }; 256];

245
core/src/mos6502cpu.rs
View File

@ -1,11 +1,13 @@
use crate::address_mode::AddressMode;
use crate::constants::constants_system::{OFFSET_INT_VECTOR, OFFSET_RESET_VECTOR, SIZE_64KB};
use crate::constants::constants_isa_op::ISA_OP_NOP;
use crate::instruction::Instruction;
use crate::mos6502flags::{Mos6502Flag, Mos6502Flags};
use crate::mos6502flags::Mos6502Flag::{Carry, Decimal, Interrupt, Overflow};
use crate::mos6502flags::Mos6502Flag::*;
use crate::op_info::OpInfo;
use crate::operand::Operand;
use crate::operation::Operation;
use crate::constants::constants_system::*;
use crate::instruction_table::INSTRUCTION_TABLE;
pub struct Mos6502Cpu {
// this is public for rendering quickly.
@ -22,7 +24,9 @@ pub struct Mos6502Cpu {
ir: Instruction, // Instruction Register
oi: OpInfo,
has_reset: bool,
iv: u16 // Interrupt Vector
iv: u16, // Interrupt Vector
cycle_carry: u16, // Value to hold between microsteps
ir_bytes: Box<[u8]>
}
impl Default for Mos6502Cpu {
@ -33,28 +37,25 @@ impl Default for Mos6502Cpu {
let mut working = Mos6502Cpu {
memory: boxed_array,
a: 0,
x: 0,
y: 0,
a: 0x00,
x: 0x00,
y: 0x00,
flags: Default::default(),
pc: 0xfffd,
s: 0,
microcode_step: 0,
address_bus: 0,
data_bus: 0,
s: 0x00,
microcode_step: 0x00,
address_bus: 0x00,
data_bus: 0x00,
ir: Instruction {
op: Operation::NOP,
mode: AddressMode::Implied,
operand: Operand::None,
},
oi: OpInfo {
operation: Operation::NOP,
mode: AddressMode::Implied,
length: 1,
cycles: 2,
},
oi: INSTRUCTION_TABLE[ISA_OP_NOP as usize].unwrap(),
has_reset: false,
iv: 0xfffe
iv: 0xfffe,
cycle_carry: 0x0000,
ir_bytes: [].into()
};
working.reset_cpu();
working
@ -68,28 +69,8 @@ impl Mos6502Cpu {
let boxed_array: Box<[u8; SIZE_64KB]> = boxed_slize.try_into().expect("Failed to allocate system memory");
let mut working = Mos6502Cpu {
memory: boxed_array,
a: 0,
x: 0,
y: 0,
flags: Mos6502Flags::default(),
pc: 0,
s: 0xfd,
microcode_step: 0,
address_bus: 0x0000,
data_bus: 0x00,
ir: Instruction {
op: Operation::NOP,
mode: AddressMode::Implied,
operand: Operand::None,
},
oi: OpInfo {
operation: Operation::NOP,
mode: AddressMode::Implied,
length: 1,
cycles: 2,
},
has_reset: false,
iv: 0xfffe
ir_bytes: [].into(),
..Default::default()
};
working.reset_cpu();
working
@ -159,9 +140,8 @@ impl Mos6502Cpu {
}
/// Ticks the CPU
/// Returns
/// AddressBus, DataBus, RW flag
pub fn tick(&mut self) -> (u16, u8, bool) {
pub fn tick(&mut self) {
println!("PREPARiNG TO TICK CPU AT PC 0x{:04x}", self.pc);
if self.microcode_step == 0 {
println!("OUT OF MICROSTEPS. Decoding the next instruction");
@ -176,9 +156,27 @@ impl Mos6502Cpu {
// set the counter to the number of steps left
} else {
// run 1 microcode step
println!("Microstep {} for {:?}", self.microcode_step, self.ir.op);
println!("Microstep {}/{} for {:?}", self.microcode_step, self.oi.cycles, self.ir.op);
match self.ir.op {
Operation::ADC => {
match self.microcode_step {
1 => {
match self.ir.mode {
AddressMode::Immediate => {}
AddressMode::ZeroPage => {}
AddressMode::ZeroPageX => {}
AddressMode::Absolute => {}
AddressMode::AbsoluteX => {}
AddressMode::AbsoluteY => {}
AddressMode::Indirect => {}
AddressMode::IndirectX => {}
AddressMode::IndirectY => {}
_ => {}
}
},
2 => {},
_ => {}
}
}
Operation::AND => {}
Operation::ASL => {}
@ -207,7 +205,65 @@ impl Mos6502Cpu {
Operation::CMP => {}
Operation::CPX => {}
Operation::CPY => {}
Operation::DEC => {}
Operation::DEC => {
match self.microcode_step {
// DEC Step 1
1 => {
let working_value = match self.oi.mode {
AddressMode::ZeroPage => {
// read from
let offset = match self.ir.operand {
Operand::Byte(z) => {
z
}
_ => { 0x00 }
};
println!("READING FROM MEMORY AT 0x{offset:04x}");
self.memory[offset as usize]
// self.peek(offset);
}
AddressMode::ZeroPageX => {
let offset = match self.ir.operand {
Operand::Byte(z) => {
z
}
_ => { 0x00 }
};
// self.memory.peek(offset + self.x);
self.memory[offset as usize]
}
AddressMode::Absolute => {
let offset = match self.ir.operand {
Operand::Word(offset) => {
offset
}
_ => { 0x00 }
};
// self.memory.peek(offset)
self.memory[offset as usize]
}
AddressMode::AbsoluteX => {
let offset = match self.ir.operand {
Operand::Word(offset) => {
offset
}
_ => { 0x00 }
};
// self.memory.peek(offset + self.x);
self.memory[offset as usize]
}
_ => {
0x00
}
};
}
// DEC write memory
2 => {
self.a = self.cycle_carry as u8;
}
_ => {}
}
}
Operation::DEX => {
if self.microcode_step == 1 {
let (new_x, new_carry) = self.x.overflowing_sub(1);
@ -264,10 +320,28 @@ impl Mos6502Cpu {
_ => {}
}
}
AddressMode::ZeroPageX => {}
AddressMode::ZeroPageX => {
match self.ir.operand {
Operand::Byte(value) => {
let x_offset = self.x;
self.a = self.memory[(value + x_offset) as usize];
}
_ => {}
}
}
AddressMode::ZeroPageY => {}
AddressMode::Absolute => {}
AddressMode::AbsoluteX => {}
AddressMode::Absolute => {
if let Operand::Word(offset) = self.ir.operand {
println!("Loading from absolute address 0x{offset:04x}");
self.a = self.memory[offset as usize];
}
}
AddressMode::AbsoluteX => {
if let Operand::Word(offset) = self.ir.operand {
self.a = self.memory[(offset + self.x as u16) as usize];
}
}
AddressMode::AbsoluteY => {}
AddressMode::Indirect => {}
AddressMode::IndirectX => {}
@ -385,8 +459,6 @@ impl Mos6502Cpu {
}
self.microcode_step -= 1;
}
(0,0,false)
}
pub fn dump(&self) {
@ -398,16 +470,12 @@ impl Mos6502Cpu {
(self.pc, self.a, self.x, self.y, self.address_bus, self.data_bus, self.microcode_step)
}
fn run_microstep(&self, instruction: Instruction, step: u8) {
}
}
#[cfg(test)]
mod test {
use crate::constants::constants_isa_op::*;
use crate::instruction_table::INSTRUCTION_TABLE;
use crate::instruction_table::{INSTRUCTION_CYCLES, INSTRUCTION_TABLE};
use super::*;
#[test]
@ -445,7 +513,7 @@ mod test {
cpu.memory[0x6000] = ISA_OP_CLI;
cpu.pc = 0x6000;
for _ in 0..INSTRUCTION_TABLE[ISA_OP_CLI as usize].unwrap().cycles { cpu.tick(); }
for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_CLI) { cpu.tick(); }
assert!(!cpu.peek_flag(Interrupt));
@ -458,7 +526,7 @@ mod test {
cpu.memory[0x6000] = ISA_OP_CLV;
cpu.pc = 0x6000;
for _ in 0..INSTRUCTION_TABLE[ISA_OP_CLV as usize].unwrap().cycles { cpu.tick(); }
for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_CLV) { cpu.tick(); }
assert!(!cpu.peek_flag(Overflow));
}
@ -470,24 +538,73 @@ mod test {
cpu.memory[0x6001] = 0xab;
cpu.pc = 0x6000;
for _ in 0..INSTRUCTION_TABLE[ISA_OP_LDA_I as usize].unwrap().cycles { cpu.tick(); }
for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_LDA_I) { cpu.tick(); }
assert_eq!(cpu.a, 0xab);
}
#[test]
fn lda_zx() {
let mut cpu = Mos6502Cpu::default();
cpu.poke_x(1);
cpu.memory[0x6000] = ISA_OP_LDA_ZX;
cpu.memory[0x6001] = 0xab;
cpu.memory[0x00ac] = 0xbe;
cpu.pc = 0x6000;
for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_LDA_ZX) { cpu.tick(); };
// println!("MEMORY AT 0x00aa, ab, ac, ad, ae -> {:02x} {:02x} {:02x} {:02x} {:02x}", cpu.memory[0x00aa], cpu.memory[0x00ab], cpu.memory[0x00ac], cpu.memory[0x00ad], cpu.memory[0x00ae]);
// cpu.dump();
assert_eq!(cpu.peek_a(), 0xbe);
assert!(!cpu.peek_flag(Zero));
assert!(!cpu.peek_flag(Carry));
assert!(!cpu.peek_flag(Negative));
}
#[test]
fn lda_zeropage() {
let mut cpu = Mos6502Cpu::default();
cpu.memory[0x6000] = ISA_OP_LDA_Z;
cpu.memory[0x6001] = 0xab;
// Load ZeroPage
cpu.memory[0x00ab] = 0xbe;
cpu.pc = 0x6000;
for _ in 0..INSTRUCTION_TABLE[ISA_OP_LDA_Z as usize].unwrap().cycles + 1 { cpu.tick(); }
for _ in 0..INSTRUCTION_CYCLES(ISA_OP_LDA_Z) { cpu.tick(); }
assert_eq!(cpu.a, 0xbe);
}
#[test]
fn lda_absolute() {
let mut cpu = Mos6502Cpu::default();
cpu.memory[0x6000] = ISA_OP_LDA_ABS;
cpu.memory[0x6001] = 0xef;
cpu.memory[0x6002] = 0xbe;
cpu.memory[0xbeef] = 0xab;
cpu.pc = 0x6000;
for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_LDA_ABS) { cpu.tick(); }
assert_eq!(cpu.a, 0xab);
}
#[test]
fn lda_absolutex() {
let mut cpu = Mos6502Cpu::default();
cpu.memory[0x6000] = ISA_OP_LDA_ABSX;
cpu.memory[0x6001] = 0xef;
cpu.memory[0x6002] = 0xbe;
cpu.poke_x(0x01);
cpu.memory[0xbef0] = 0xab;
cpu.pc = 0x6000;
for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_LDA_ABS) { cpu.tick(); }
assert_eq!(cpu.a, 0xab);
}
#[test]
fn dex_inx() {
let mut cpu = Mos6502Cpu::default();
@ -496,9 +613,9 @@ mod test {
cpu.memory[0x6001] = ISA_OP_INX;
cpu.pc = 0x6000;
for _ in 0..=INSTRUCTION_TABLE[ISA_OP_DEX as usize].unwrap().cycles { cpu.tick(); }
for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_DEX) { cpu.tick(); }
assert_eq!(0xaa, cpu.x);
for _ in 0..=INSTRUCTION_TABLE[ISA_OP_INX as usize].unwrap().cycles { cpu.tick(); }
for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_INX) { cpu.tick(); }
assert_eq!(0xab, cpu.x);
}
@ -510,9 +627,9 @@ mod test {
cpu.memory[0x6001] = ISA_OP_INY;
cpu.pc = 0x6000;
for _ in 0..=INSTRUCTION_TABLE[ISA_OP_DEY as usize].unwrap().cycles { cpu.tick(); }
for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_DEY) { cpu.tick(); }
assert_eq!(0xaa, cpu.peek_y());
for _ in 0..=INSTRUCTION_TABLE[ISA_OP_INY as usize].unwrap().cycles { cpu.tick(); }
for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_INY) { cpu.tick(); }
assert_eq!(0xab, cpu.peek_y());
}
@ -524,9 +641,9 @@ mod test {
cpu.memory[0x6001] = ISA_OP_ROR_A;
cpu.pc = 0x6000;
for _ in 0..=INSTRUCTION_TABLE[ISA_OP_ROL_A as usize].unwrap().cycles { cpu.tick(); }
for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_ROL_A) { cpu.tick(); }
assert_eq!(cpu.peek_a(), 0b0101_0101);
for _ in 0..=INSTRUCTION_TABLE[ISA_OP_ROR_A as usize].unwrap().cycles { cpu.tick(); }
for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_ROR_A) { cpu.tick(); }
assert_eq!(cpu.peek_a(), 0b1010_1010);
}
}

42
core/src/operation.rs
View File

@ -5,117 +5,121 @@ pub enum Operation {
///
/// Affects flags: N, V, Z, C
///
/// Addressing Modes: Immediate, ZeroPage, ZeroPageX, Absolute, AbsoluteX, AbsoluteY, IndirectX, IndirectY
/// Addressing Modes: Immediate (2/2), ZeroPage (2/3), ZeroPageX (2/4), Absolute (3/4),
/// AbsoluteX (3/4), AbsoluteY (3/4), IndirectX (2/6), IndirectY (2/5)
ADC,
/// Logical AND with Accumulator
///
/// Affects flags: N, Z
///
/// Addressing Modes: Immediate, ZeroPage, ZeroPageX, Absolute, AbsoluteX, AbsoluteY, IndirectX, IndirectY
/// Addressing Modes: Immediate (2/2), ZeroPage (2/3), ZeroPageX (2/4), Absolute (3/4),
/// AbsoluteX (3/4), AbsoluteY (3/4), IndirectX (2/6), IndirectY (2/5)
AND,
/// Arithmetic Shift Left
///
/// Affects flags: N, Z, C
///
/// Addressing Modes: Accumulator, ZeroPage, ZeroPageX, Absolute, AbsoluteX
/// Addressing Modes: Accumulator (1/2), ZeroPage (2/5), ZeroPageX (2/6), Absolute (3/6),
/// AbsoluteX (3/7)
ASL,
/// Branch if Carry Clear
///
/// Addressing Modes: Relative
/// Addressing Modes: Relative (2/2)
BCC,
/// Branch if Carry Set
///
/// Addressing Modes: Relative
/// Addressing Modes: Relative (2/2)
BCS,
/// Branch if Equal (Zero Set)
///
/// Addressing Modes: Relative
/// Addressing Modes: Relative (2/2)
BEQ,
/// Bit Test
///
/// Affects flags: N, V, Z
///
/// Addressing Modes: ZeroPage, Absolute
/// Addressing Modes: ZeroPage (2/3), Absolute (3/4)
BIT,
/// Branch if Minus (Negative Set)
///
/// Addressing Modes: Relative
/// Addressing Modes: Relative (2/2)
BMI,
/// Branch if Not Equal (Zero Clear)
///
/// Addressing Modes: Relative
/// Addressing Modes: Relative (2/2)
BNE,
/// Branch if Positive (Negative Clear)
///
/// Addressing Modes: Relative
/// Addressing Modes: Relative (2/2)
BPL,
/// Force Interrupt
///
/// Affects flags: B
///
/// Addressing Modes: Implied
/// Addressing Modes: Implied (1/7)
BRK,
/// Branch if Overflow Clear
///
/// Addressing Modes: Relative
/// Addressing Modes: Relative (2/2)
BVC,
/// Branch if Overflow Set
///
/// Addressing Modes: Relative
/// Addressing Modes: Relative (2/2)
BVS,
/// Clear Carry Flag
///
/// Affects flags: C
///
/// Addressing Modes: Implied
/// Addressing Modes: Implied (1/2)
CLC,
/// Clear Decimal Mode
///
/// Affects flags: D
///
/// Addressing Modes: Implied
/// Addressing Modes: Implied (1/2)
CLD,
/// Clear Interrupt Disable
///
/// Affects flags: I
///
/// Addressing Modes: Implied
/// Addressing Modes: Implied (1/2)
CLI,
/// Clear Overflow Flag
///
/// Affects flags: V
///
/// Addressing Modes: Implied
/// Addressing Modes: Implied (2/2)
CLV,
/// Compare Accumulator
///
/// Affects flags: N, Z, C
///
/// Addressing Modes: Immediate, ZeroPage, ZeroPageX, Absolute, AbsoluteX, AbsoluteY, IndirectX, IndirectY
/// Addressing Modes: Immediate (2/2), ZeroPage (2/3), ZeroPageX (2/4), Absolute (3/4),
/// AbsoluteX (3/4), AbsoluteY (3/4), IndirectX (2/6), IndirectY (2/5)
CMP,
/// Compare X Register
///
/// Affects flags: N, Z, C
///
/// Addressing Modes: Immediate, ZeroPage, Absolute
/// Addressing Modes: Immediate (2/2), ZeroPage (2/3), Absolute (3/4)
CPX,
/// Compare Y Register

0
core/tests/execution_tests.rs Normal file
View File