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attempt chatgpt emulator for display

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This commit is contained in:
Trevor Merritt 2025-07-03 11:41:54 -04:00
parent 8509b20109
commit e4405cc225
2 changed files with 42 additions and 10 deletions
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9
beneater/src/parts/display_matrix.rs
View File

@ -13,7 +13,8 @@ pub enum MatrixEntryMode {
pub struct DisplayMatrix { pub struct DisplayMatrix {
width: f32, width: f32,
height: f32, height: f32,
text_buffer: String, text_buffer: [u8; 80],
cgram: [u8; 64],
data_bus: DataBus, data_bus: DataBus,
rs: bool, rs: bool,
rw: bool, rw: bool,
@ -21,7 +22,7 @@ pub struct DisplayMatrix {
busy: bool, busy: bool,
entry_mode: MatrixEntryMode, entry_mode: MatrixEntryMode,
cursor: bool, cursor: bool,
on: bool, display_on: bool,
blink: bool, blink: bool,
cursor_shift: bool, cursor_shift: bool,
display_shift: bool, display_shift: bool,
@ -69,7 +70,7 @@ impl DisplayMatrix {
cursor_position: 0x00, cursor_position: 0x00,
busy: false, busy: false,
entry_mode: MatrixEntryMode::InsertShift, entry_mode: MatrixEntryMode::InsertShift,
on: false, display_on: false,
cursor: false, cursor: false,
blink: false, blink: false,
cursor_shift: false, cursor_shift: false,
@ -122,7 +123,7 @@ impl DisplayMatrix {
} }
0b0000_1000..=0b0000_1111 => { 0b0000_1000..=0b0000_1111 => {
// display control // display control
self.on = self.data_bus.data & 0b100 == 0b100; self.display_on = self.data_bus.data & 0b100 == 0b100;
self.cursor = self.data_bus.data & 0b10 == 0b10; self.cursor = self.data_bus.data & 0b10 == 0b10;
self.blink = self.data_bus.data & 0b1 == 0b1; self.blink = self.data_bus.data & 0b1 == 0b1;
} }

43
core/src/mos6502cpu.rs
View File

@ -1,3 +1,4 @@
use log::trace;
use crate::address_mode::AddressMode; use crate::address_mode::AddressMode;
use crate::constants::constants_isa_op::ISA_OP_NOP; use crate::constants::constants_isa_op::ISA_OP_NOP;
use crate::instruction::Instruction; use crate::instruction::Instruction;
@ -218,7 +219,7 @@ impl Mos6502Cpu {
} }
_ => { 0x00 } _ => { 0x00 }
}; };
println!("READING FROM MEMORY AT 0x{offset:04x}"); trace!("READING FROM MEMORY AT 0x{offset:04x}");
self.memory[offset as usize] self.memory[offset as usize]
// self.peek(offset); // self.peek(offset);
} }
@ -299,7 +300,10 @@ impl Mos6502Cpu {
_ => {} _ => {}
} }
} }
Operation::JSR => {} Operation::JSR => {
// push pc to stack.
// jump to the subroutine.
}
Operation::LDA => { Operation::LDA => {
match self.oi.mode { match self.oi.mode {
AddressMode::Immediate => { AddressMode::Immediate => {
@ -329,7 +333,6 @@ impl Mos6502Cpu {
_ => {} _ => {}
} }
} }
AddressMode::ZeroPageY => {}
AddressMode::Absolute => { AddressMode::Absolute => {
if let Operand::Word(offset) = self.ir.operand { if let Operand::Word(offset) = self.ir.operand {
println!("Loading from absolute address 0x{offset:04x}"); println!("Loading from absolute address 0x{offset:04x}");
@ -342,7 +345,11 @@ impl Mos6502Cpu {
self.a = self.memory[(offset + self.x as u16) as usize]; self.a = self.memory[(offset + self.x as u16) as usize];
} }
} }
AddressMode::AbsoluteY => {} AddressMode::AbsoluteY => {
if let Operand::Word(offset) = self.ir.operand {
self.a = self.memory[(offset + self.y as u16) as usize];
}
}
AddressMode::Indirect => {} AddressMode::Indirect => {}
AddressMode::IndirectX => {} AddressMode::IndirectX => {}
AddressMode::IndirectY => {} AddressMode::IndirectY => {}
@ -430,7 +437,16 @@ impl Mos6502Cpu {
} }
} }
} }
AddressMode::AbsoluteY => {} AddressMode::AbsoluteY => {
match self.ir.operand {
Operand::Word(offset) => {
self.memory[(offset + self.y as u16) as usize] = self.a;
}
_ => {
// Invalid Parameter
}
}
}
AddressMode::IndirectX => {} AddressMode::IndirectX => {}
AddressMode::IndirectY => {} AddressMode::IndirectY => {}
_ => { _ => {
@ -600,7 +616,22 @@ mod test {
cpu.memory[0xbef0] = 0xab; cpu.memory[0xbef0] = 0xab;
cpu.pc = 0x6000; cpu.pc = 0x6000;
for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_LDA_ABS) { cpu.tick(); } for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_LDA_ABSX) { cpu.tick(); }
assert_eq!(cpu.a, 0xab);
}
#[test]
fn lda_absolutey() {
let mut cpu = Mos6502Cpu::default();
cpu.memory[0x6000] = ISA_OP_LDA_ABSY;
cpu.memory[0x6001] = 0xef;
cpu.memory[0x6002] = 0xbe;
cpu.poke_y(0x01);
cpu.memory[0xbef0] = 0xab;
cpu.pc = 0x6000;
for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_LDA_ABSY) { cpu.tick(); }
assert_eq!(cpu.a, 0xab); assert_eq!(cpu.a, 0xab);
} }