writes bins better now

beneater/src/bin/beneater.rs

@@ -4,14 +4,39 @@ use beneater::parts::ben_eater_pc::BenEaterPC;
 use beneater::parts::cpu_display::CpuDisplay;
 use macroquad::prelude::*;
 use macroquad::telemetry::frame;
+use core::mos6502cpu::cpu::Mos6502Cpu;
+use core::periph::at28c256::At28C256;
+use core::periph::hm62256::Hm62256;
+use core::constants::constants_system::*;
+
+/// BenEater computer represents the 'Ben Eater' 6502 breadboard computer.
+/// This was built along watching the video series where Ben builds a
+/// 6502 on a breadboard and explains each step.
+///
+pub struct BenEater {
+    cpu: Mos6502Cpu,
+    ram: At28C256,
+    rom: Hm62256
+}
+
+impl BenEater {
+    pub fn new(rom: &[u8; SIZE_32KB]) -> BenEater {
+
+    }
+}
+
+
 #[macroquad::main("Ben Eaters PC")]
 async fn main() {
     println!("Taxation is Theft");
 
-    let mut backplane = Backplane::new();
-    backplane.load_rom("resources/beneater/roms/ror.bin");
+    let rom_to_run = fs::read("resources/beneater/roms/ror.bin");
+    let mut pc = BenEater::new(&rom_to_run);
 
-    let mut dm = DisplayMatrix::new(200.0, 50.0);
+    let mut backplane = Backplane::new();
+    // backplane.load_rom("resources/beneater/roms/ror.bin");
+
+    // let mut dm = DisplayMatrix::new(200.0, 50.0);
 
     // dm.push_letter('T');
     let mut frame_number: u32 = 0x00;
@@ -20,18 +45,18 @@ async fn main() {
         clear_background(BLUE);
 
         draw_text("Ben Eater", 20.0, 20.0, 30.0, BLACK);
-        dm.render(20.0, 40.0);
+        // dm.render(20.0, 40.0);
         //  CpuDisplay::render(&computer.cpu, 20.0, 120.0);
 
         frame_number += 1;
 
         if frame_number.is_multiple_of(60) {
-            dm.push_letter('X');
-            computer.tick_system();
+            // dm.push_letter('X');
+       //     computer.tick_system();
         }
 
         if frame_number.is_multiple_of(60 * 6) {
-            dm.clear_display()
+            // dm.clear_display()
         }
 
         next_frame().await

beneater/src/bin/make_rom.rs

@@ -1,16 +1,46 @@
+#![feature(slice_as_array)]
+
 use core::constants::constants_system::SIZE_32KB;
+use core::constants::constants_isa_op::*;
 use std::fs;
+use std::path::Path;
+
+fn le_swap(to_swap: &[u8; SIZE_32KB]) -> [u8; 32768] {
+
+    let mut work: [u8; SIZE_32KB] = [0x00; SIZE_32KB];
+
+    for i in (0..SIZE_32KB).step_by(2) {
+        work[i] = to_swap[i+1];
+        work[i + 1] = to_swap[i];
+    }
+    work
+}
 
 fn main() {
     // make the rom data in memory.
-    // Fill with 0x6a  -> ROR, A
-    let vec = vec![0x6a; SIZE_32KB];
-    let slice: Box<[u8]> = vec.into_boxed_slice();
-    let mut array: Box<[u8; SIZE_32KB]> = slice.try_into().expect("Unable to make rom in ram");
+    // Fill with 0xea -> NOP
+    let mut vec: [u8; SIZE_32KB] = [ISA_OP_NOP; SIZE_32KB];
 
-    array[0] = 0xa9; // LDA #$ab
-    array[1] = 0xab; //      1010 1011
+    vec[0] = ISA_OP_LDA_I; // LDA #$ab
+    vec[1] = 0b1010_1011; //      1010 1011
+    vec[2] = 0x02; // --
+    vec[3] = 0x03; // --
+
+    vec[0x4000] = ISA_OP_LDA_I;
+    vec[0x4001] = 0b0101_0100;
+    vec[0x4002] = ISA_OP_JMP_ABS;
+    vec[0x4003] = 0x00;
+    vec[0x4004] = 0x40;
+    vec[0x4005] = ISA_OP_NOP;
+
+    vec[0x7ffc] = 0x12; // Reset Vector
+    vec[0x7ffd] = 0x34;
+    vec[0x7ffe] = 0x43; // Interrupt Vector
+    vec[0x7fff] = 0x21;
+
+
+    vec = le_swap(&vec);
 
     // write the rom to disk
-    fs::write("outputfile.bin", array.as_slice());
+    fs::write("outputfile.bin", &vec[..]).expect("TODO: panic message");
 }

beneater/src/bin/urn.rs

@@ -8,7 +8,7 @@ fn main() {
 
     let mut backplane = Backplane::new();
 
-    backplane.load_rom();
+    //backplane.load_rom();
     println!("Backplane is live.");
 
     let mut new_program = [0x00u8; SIZE_32KB];
@@ -21,9 +21,9 @@ fn main() {
     );
     // println!("{:?}", new_program);
 
-    backplane.rom.program(&new_program);
-    backplane.cpu.pc = 0x6000;
-    backplane.memory[0x6000] = ISA_OP_LDA_I;
-    backplane.memory[0x6001] = 0xab;
-    backplane.tick();
+    // backplane.rom.program(&new_program);
+    // backplane.cpu.pc = 0x6000;
+    // backplane.memory[0x6000] = ISA_OP_LDA_I;
+    // backplane.memory[0x6001] = 0xab;
+    // backplane.tick();
 }

beneater/src/lib.rs

@@ -1,3 +1,2 @@
 pub mod parts;
 pub mod backplane;
-mod backplane;

beneater/src/parts/backplane.rs

@@ -1,9 +1,10 @@
 use crate::parts::mos6522_peripheral::Mos6522Peripheral;
 use crate::parts::via6522::VIA6522;
 use core::constants::constants_system::*;
-use core::mos6502cpu::Mos6502Cpu;
+use core::mos6502cpu::cpu::Mos6502Cpu;
 use core::periph::at28c256::At28C256;
 use core::periph::rom_chip::RomChip;
+use core::constants::constants_via6522::*;
 
 /// Backplane
 ///
@@ -60,7 +61,7 @@ impl Backplane {
 
         // if we are reading
         if rw {
-            println!("CPU HAS SET READ FLAG FOR ADDRESS {address:04x} with data 0x{data:02x}");
+            println!("CPU HAS SET READ FLAG FOR ADDRESS {:04x} with data 0x{:02x}", self.address_bus, self.data_bus);
             match self.address_bus {
                 0x0000..=0x3fff => {
                     // read from ram
@@ -75,13 +76,13 @@ impl Backplane {
                 }
             }
         } else {
-            println!("CPU HAS SET WRITE FLAG FOR ADDRESS 0x{address:04x} with data 0x{data:02x}");
+            println!("CPU HAS SET WRITE FLAG FOR ADDRESS 0x{:04x} with data 0x{:02x}", self.address_bus, self.data_bus);
             match self.address_bus {
                 0x6000..=0x600f => {
                     self.via.write((self.address_bus - 0x6000) as u8, self.data_bus);
                 },
                 0x0000..=0x3fff => {
-                    self.memory[self.address_bus] = self.data_bus;
+                    self.memory[self.address_bus as usize] = self.data_bus;
                 }
                 _ => {
                     println!("ATTEMPT TO WRITE OUTSIDE OF MEMORY");

beneater/src/parts/ben_eater_pc.rs

@@ -1,6 +1,6 @@
 use crate::parts::clock::Clock;
 use core::constants::constants_system::*;
-use core::mos6502cpu::Mos6502Cpu;
+use core::mos6502cpu::cpu::Mos6502Cpu;
 use std::fs;
 use std::fs::File;
 use std::io::{BufReader, Read};

beneater/src/parts/cpu_display.rs

@@ -1,4 +1,4 @@
-use core::mos6502cpu::Mos6502Cpu;
+use core::mos6502cpu::cpu::Mos6502Cpu;
 use macroquad::color::{BLACK, Color};
 use macroquad::prelude::*;
 use macroquad::text::draw_text;
@@ -7,7 +7,7 @@ pub struct CpuDisplay {}
 impl CpuDisplay {
     pub fn render(cpu: &Mos6502Cpu, x_offset: f32, y_offset: f32) {
         // get the data to display...
-        let (pc, a, x, y, address_bus, data_bus, microsteps_remaining) = cpu.dump_data();
+        let (pc, a, x, y, address_bus, data_bus, microsteps_remaining, reset_vector, interrupt_vector) = cpu.dump_data();
 
         // ...build the interface
         Self::draw_square(x_offset, y_offset, x_offset + 300.0, y_offset + 85.0, BLACK);

cli/src/bin/rom_only.rs

@@ -0,0 +1,18 @@
+use clap::Parser;
+use core::computers::rom_only::backplane::Backplane;
+
+#[derive(Parser)]
+struct CliOptions {
+    offset: u16,
+    bytes: u16,
+    filename: String
+}
+
+fn main() {
+    println!("Taxation is theft");
+
+    let opts = CliOptions::parse();
+
+    let mut rom_only = Backplane::new();
+    rom_only.tick()
+}

cli/src/bin/ticker.rs

@@ -1,4 +1,4 @@
-use core::mos6502cpu::Mos6502Cpu;
+use core::mos6502cpu::cpu::Mos6502Cpu;
 
 fn main() {
     let x = Mos6502Cpu::default();

core/src/computers/beneater/beneater.rs

@@ -1,5 +0,0 @@
-/// BenEater computer represents the 'Ben Eater' 6502 breadboard computer.
-/// This was built along watching the video series where Ben builds a
-/// 6502 on a breadboard and explains each step.
-///
-pub struct BenEater {}

core/src/computers/rom_only/backplane.rs

@@ -3,7 +3,9 @@ use crate::periph::hm62256::Hm62256;
 use crate::periph::rom_chip::RomChip;
 
 pub struct Backplane {
-    rom: Hm62256
+    rom: Hm62256,
+    data_bus: u8,
+    address_bus: u16
 }
 
 impl Backplane {
@@ -13,7 +15,9 @@ impl Backplane {
     
     pub fn program(rom: &[u8; SIZE_32KB]) -> Backplane {
         Backplane {
-            rom: *Hm62256::program(rom)
+            rom: *Hm62256::program(rom),
+            address_bus: 0x0000,
+            data_bus: 0x00
         }
     }
     

core/src/constants/constants_system.rs

@@ -5,7 +5,3 @@ pub const SIZE_64KB: usize = SIZE_1KB * 64;
 pub const OFFSET_RESET_VECTOR: u16 = 0xfffc;
 pub const OFFSET_INT_VECTOR: u16 = 0xfffe;
 
-pub const VIA6522_ORB: u8 = 0;
-pub const VIA6522_ORA: u8 = 1;
-pub const VIA6522_DDRB: u8 = 2;
-pub const VIA6522_DDRA: u8 = 3;

core/src/constants/constants_via6522.rs

@@ -0,0 +1,20 @@
+pub const VIA6522_ORB: u8 = 0b0000;
+pub const VIA6522_ORA: u8 = 0b0001;
+pub const VIA6522_DDRB: u8 = 0b0010;
+pub const VIA6522_DDRA: u8 = 0b0011;
+
+/// Timer 1 Write Latch
+pub const VIA6522_T1WL: u8 = 0b0100;
+/// Timer 1 Read Counter High
+pub const VIA6522_T1CL: u8 = 0b0101;
+pub const VIA6522_T1CH: u8 = 0b0110;
+pub const VIA6522_T1LL: u8 = 0b0111;
+pub const VIA6522_T1LH: u8 = 0b1000;
+pub const VIA6522_T2LL: u8 = 0b1001;
+pub const VIA6522_T2CH: u8 = 0b1010;
+pub const VIA6522_SR:  u8 =  0b1011;
+pub const VIA6522_ACR: u8 =  0b1100;
+pub const VIA6522_PCR: u8 =  0b1101;
+pub const VIA6522_IFR: u8 =  0b1110;
+pub const VIA6522_IER: u8 =  0b1111;
+

core/src/constants/mod.rs

@@ -1,3 +1,4 @@
 pub mod constants_isa_op;
 pub mod constants_isa_stub;
 pub mod constants_system;
+pub mod constants_via6522;

core/src/instruction_table.rs

@@ -31,11 +31,11 @@ use crate::op_info::OpInfo;
 use crate::operation::Operation;
 use crate::operation::Operation::*;
 
-pub fn INSTRUCTION_CYCLES(instruction: u8) -> u8 {
+pub fn instruction_cycles(instruction: u8) -> u8 {
     INSTRUCTION_TABLE[instruction as usize].unwrap().cycles
 }
 
-pub fn INSTRUCTION_LENGTH(instruction: u8) -> u8 {
+pub fn instruction_length(instruction: u8) -> u8 {
     INSTRUCTION_TABLE[instruction as usize].unwrap().length
 }
 

core/src/mos6502cpu/cpu.rs

@@ -483,7 +483,7 @@ impl Mos6502Cpu {
 mod test {
     use super::*;
     use crate::constants::constants_isa_op::*;
-    use crate::instruction_table::{INSTRUCTION_CYCLES, INSTRUCTION_TABLE};
+    use crate::instruction_table::{instruction_cycles, INSTRUCTION_TABLE};
 
     #[test]
     fn clc() {
@@ -496,7 +496,7 @@ mod test {
         cpu.pc = 0x6000;
 
         // Tick the CPU through the instruction
-        for _ in 0..INSTRUCTION_CYCLES(ISA_OP_CLC) {
+        for _ in 0..instruction_cycles(ISA_OP_CLC) {
             cpu.tick();
         }
 
@@ -510,7 +510,7 @@ mod test {
         cpu.memory[0x6000] = ISA_OP_CLD;
         cpu.pc = 0x6000;
 
-        for _ in 0..INSTRUCTION_CYCLES(ISA_OP_CLD) {
+        for _ in 0..instruction_cycles(ISA_OP_CLD) {
             cpu.tick();
         }
 
@@ -524,7 +524,7 @@ mod test {
         cpu.memory[0x6000] = ISA_OP_CLI;
         cpu.pc = 0x6000;
 
-        for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_CLI) {
+        for _ in 0..=instruction_cycles(ISA_OP_CLI) {
             cpu.tick();
         }
 
@@ -538,7 +538,7 @@ mod test {
         cpu.memory[0x6000] = ISA_OP_CLV;
         cpu.pc = 0x6000;
 
-        for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_CLV) {
+        for _ in 0..=instruction_cycles(ISA_OP_CLV) {
             cpu.tick();
         }
 
@@ -552,7 +552,7 @@ mod test {
         cpu.memory[0x6001] = 0xab;
         cpu.pc = 0x6000;
 
-        for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_LDA_I) {
+        for _ in 0..=instruction_cycles(ISA_OP_LDA_I) {
             cpu.tick();
         }
 
@@ -568,7 +568,7 @@ mod test {
         cpu.memory[0x00ac] = 0xbe;
         cpu.pc = 0x6000;
 
-        for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_LDA_ZX) {
+        for _ in 0..=instruction_cycles(ISA_OP_LDA_ZX) {
             cpu.tick();
         }
 
@@ -589,7 +589,7 @@ mod test {
         cpu.memory[0x00ab] = 0xbe;
         cpu.pc = 0x6000;
 
-        for _ in 0..INSTRUCTION_CYCLES(ISA_OP_LDA_Z) {
+        for _ in 0..instruction_cycles(ISA_OP_LDA_Z) {
             cpu.tick();
         }
 
@@ -605,7 +605,7 @@ mod test {
         cpu.memory[0x0eef] = 0xab;
         cpu.pc = 0x6000;
 
-        for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_LDA_ABS) {
+        for _ in 0..=instruction_cycles(ISA_OP_LDA_ABS) {
             cpu.tick();
         }
 
@@ -622,7 +622,7 @@ mod test {
         cpu.memory[0x0ef0] = 0xab;
         cpu.pc = 0x6000;
 
-        for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_LDA_ABSX) {
+        for _ in 0..=instruction_cycles(ISA_OP_LDA_ABSX) {
             cpu.tick();
         }
 
@@ -639,7 +639,7 @@ mod test {
         cpu.memory[0x0ef0] = 0xab;
         cpu.pc = 0x6000;
 
-        for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_LDA_ABSY) {
+        for _ in 0..=instruction_cycles(ISA_OP_LDA_ABSY) {
             cpu.tick();
         }
 
@@ -654,11 +654,11 @@ mod test {
         cpu.memory[0x6001] = ISA_OP_INX;
         cpu.pc = 0x6000;
 
-        for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_DEX) {
+        for _ in 0..=instruction_cycles(ISA_OP_DEX) {
             cpu.tick();
         }
         assert_eq!(0xaa, cpu.x);
-        for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_INX) {
+        for _ in 0..=instruction_cycles(ISA_OP_INX) {
             cpu.tick();
         }
         assert_eq!(0xab, cpu.x);
@@ -672,11 +672,11 @@ mod test {
         cpu.memory[0x6001] = ISA_OP_INY;
         cpu.pc = 0x6000;
 
-        for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_DEY) {
+        for _ in 0..=instruction_cycles(ISA_OP_DEY) {
             cpu.tick();
         }
         assert_eq!(0xaa, cpu.peek_y());
-        for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_INY) {
+        for _ in 0..=instruction_cycles(ISA_OP_INY) {
             cpu.tick();
         }
         assert_eq!(0xab, cpu.peek_y());
@@ -690,11 +690,11 @@ mod test {
         cpu.memory[0x6001] = ISA_OP_ROR_A;
         cpu.pc = 0x6000;
 
-        for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_ROL_A) {
+        for _ in 0..=instruction_cycles(ISA_OP_ROL_A) {
             cpu.tick();
         }
         assert_eq!(cpu.peek_a(), 0b0101_0101);
-        for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_ROR_A) {
+        for _ in 0..=instruction_cycles(ISA_OP_ROR_A) {
             cpu.tick();
         }
         assert_eq!(cpu.peek_a(), 0b1010_1010);
@@ -708,7 +708,7 @@ mod test {
         cpu.memory[0x6001] = 0xab;
         cpu.pc = 0x6000;
 
-        for _ in 0..=INSTRUCTION_CYCLES(ISA_OP_ROL_ZP) {
+        for _ in 0..=instruction_cycles(ISA_OP_ROL_ZP) {
             cpu.tick();
         }
 

core/src/periph/at28c256/mod.rs

@@ -1,6 +1,8 @@
 pub mod default;
 pub mod rom_chip;
 pub mod tick;
+mod new;
+mod program;
 
 use crate::constants::constants_system::SIZE_32KB;
 use crate::periph::rom_chip::RomChip;
@@ -16,14 +18,6 @@ pub struct At28C256 {
     data: Box<[u8; SIZE_32KB]>,
 }
 
-impl At28C256 {
-    pub fn program(&mut self, new_program: &[u8; SIZE_32KB]) {
-        // panic!("FAIL.  Cant program the chip.");
-        // println!("PROGRAMMING {:?}", new_program);
-        self.data = Box::new(*new_program);
-    }
-}
-
 #[cfg(test)]
 mod test {
     use super::*;

core/src/periph/at28c256/new.rs

@@ -0,0 +1,10 @@
+use crate::constants::constants_system::SIZE_32KB;
+use crate::periph::at28c256::At28C256;
+
+impl At28C256 {
+    pub fn new(data: &[u8; SIZE_32KB]) -> Self {
+        At28C256 {
+            data: (*data).into()
+        }
+    }
+}

core/src/periph/at28c256/program.rs

@@ -0,0 +1,10 @@
+use crate::constants::constants_system::SIZE_32KB;
+use crate::periph::at28c256::At28C256;
+
+impl At28C256 {
+    pub fn program(&mut self, new_program: &[u8; SIZE_32KB]) {
+        // panic!("FAIL.  Cant program the chip.");
+        // println!("PROGRAMMING {:?}", new_program);
+        self.data = Box::new(*new_program);
+    }
+}

core/src/periph/at28c256/tick.rs

@@ -3,8 +3,10 @@ use crate::periph::hm62256::Hm62256;
 
 impl At28C256 {
     fn tick(&mut self, address_bus: u16, data_bus: u8, read_mode: bool) -> (u16, u8) {
-        if !read_mode {
-            // has to be read mode.  its a rom.
+        if read_mode {
+            panic!("UNABLE TO WRITE TO ROM");
+        } else {
+        // has to be read mode.  its a rom.
             return (address_bus, data_bus)
         }
         (address_bus, self.data[address_bus as usize])

core/src/periph/hm62256/tick.rs

@@ -25,7 +25,9 @@ mod test {
     fn write_to_memory_read_back_works_at_0() {
         let mut ram = Hm62256::default();
 
+        // load the data to ram
         ram.tick(0x0000, 0xab, false);
+        // read the data back
         let (_, new_data) = ram.tick(0x0000, 0x00, true);
 
         assert_eq!(new_data, 0xab);

core/src/periph/mod.rs

@@ -3,3 +3,4 @@ pub mod rom_chip;
 pub mod at28c256;
 pub mod hm62256;
 pub mod ram_chip;
+pub mod mos6522;

core/src/periph/mos6522/mod.rs

@@ -0,0 +1,2 @@
+pub mod mos6522;
+mod registers;

core/src/periph/mos6522/mos6522.rs

@@ -0,0 +1,165 @@
+use std::time::Instant;
+use log::debug;
+use crate::constants::constants_via6522::*;
+
+#[derive(Default)]
+pub struct Mos6522 {
+    /// data direction
+    dda: u8,
+    ddb: u8,
+
+    /// bottom 4 address bits
+    rs0: u8,
+    rs1: u8,
+    rs2: u8,
+    rs3: u8,
+
+    /// external data bus
+    data_bus: u8,
+
+    cs1: bool,
+    cs2: bool,
+    rw: bool,
+
+    /// reset circuit - true when reset inited
+    reset: bool,
+
+    /// IRQ - true when interrupt waiting
+    irq: bool,
+
+    ira: u8,
+    ora: u8,
+    porta: u8,
+    irb: u8,
+    orb: u8,
+    portb: u8,
+
+    ca1: bool,
+    ca2: bool,
+    cb1: bool,
+    cb2: bool,
+}
+
+impl Mos6522 {
+    pub fn new() -> Self {
+        Mos6522::default()
+    }
+
+    /// tick
+    ///
+    /// data_bus -> 8 bits from the data bus
+    /// control  -> 4 bits to identify which register to control
+    pub fn tick(&mut self, data_bus: u8, control: u8, rw: bool) -> (u8) {
+        println!("Mos6522 Tick Start -> 0x{data_bus:02x} / 0x{control:02x} / {rw}");
+        if rw  {
+            // RW true = CPU is writing
+            self.data_bus = data_bus;
+            match control {
+                VIA6522_DDRA => {
+                    debug!("Setting DDA to 0x{data_bus:02x}");
+                    // setting the Data Direction for Port A
+                    self.dda = data_bus;
+                },
+                VIA6522_DDRB => {
+                    debug!("Setting DDB to 0x{data_bus:02x}");
+                    // setting the data direction for port b
+                    self.ddb = data_bus;
+                },
+                VIA6522_ORB => {
+                    // writing data to ORB
+                    let masked_data = data_bus & self.ddb;
+                    debug!("Setting ORB to 0x{data_bus:02x} / masked at 0x{masked_data:02x}");
+                    self.portb = masked_data;
+                },
+                VIA6522_ORA => {
+                    // writing data to ORA
+                    let masked_data = data_bus & self.dda;
+                    debug!("Setting ORA to 0x{data_bus:02x} / masked at 0x{masked_data:02x}");
+                    self.porta = masked_data;
+                },
+                _ => {}
+            }
+        } else {
+            // RW false = CPU is reading
+            self.data_bus = match control {
+                VIA6522_DDRA => {
+                    self.dda
+                }
+                VIA6522_DDRB => {
+                    self.ddb
+                }
+                VIA6522_ORA => {
+                    self.porta & self.dda
+                }
+                VIA6522_ORB => {
+                    self.portb & self.ddb
+                }
+                _ => {
+                    debug!("VIA got request for b{:08b} / 0x{:02x}", control, control);
+                    // do nothing.  bad address for VIA
+                    self.data_bus
+                }
+            }
+        }
+
+        (self.data_bus)
+    }
+
+    pub fn start_clocks(&mut self) {
+        loop {
+            let cycle_start = Instant::now();
+            // let duration = cycle_start.duration_since(self.clock);
+            // set the time to the new time.
+            // self.clock = cycle_start;
+        }
+    }
+}
+
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn smoke() { assert!(true); }
+
+    #[test]
+    fn registers() {
+        let mut x = Mos6522::new();
+        x.tick(0b0000_0000, VIA6522_DDRA, true);
+        assert_eq!(x.dda, 0b0000_0000);
+        x.tick(0b1111_1111, VIA6522_DDRA, true);
+        assert_eq!(x.dda, 0b1111_1111);
+
+        x.tick(0b0000_0000, VIA6522_DDRB, true);
+        assert_eq!(x.ddb, 0b0000_0000);
+        x.tick(0b1111_1111, VIA6522_DDRB, true);
+        assert_eq!(x.ddb, 0b1111_1111);
+
+        x.tick(0b0000_0000, VIA6522_ORA, true);
+        assert_eq!(x.porta, 0b0000_0000);
+        x.tick(0b1111_1111, VIA6522_ORA, true);
+        assert_eq!(x.porta, 0b1111_1111);
+
+        x.tick(0b0000_0000, VIA6522_ORB, true);
+        assert_eq!(x.portb, 0b0000_0000);
+        x.tick(0b1111_1111, VIA6522_ORB, true);
+        assert_eq!(x.portb, 0b1111_1111);
+    }
+
+    #[test]
+    fn partial_output_porta() {
+        let mut x = Mos6522::new();
+        x.tick(0b1010_1010, VIA6522_DDRA, true);
+        x.tick(0b1111_1111, VIA6522_ORA, true);
+        assert_eq!(x.porta, 0b1010_1010);
+    }
+
+    #[test]
+    fn partial_output_portb() {
+        let mut x = Mos6522::new();
+        x.tick(0b0101_0101, VIA6522_DDRB, true);
+        x.tick(0b1111_1111, VIA6522_ORB, true);
+        assert_eq!(x.portb, 0b0101_0101);
+    }
+}

core/src/periph/mos6522/registers.rs

@@ -0,0 +1,12 @@
+pub enum Via6522Registers {
+    ORA,
+    ORB,
+    DDRA,
+    DDRB,
+    T1WL,
+    T1CL,
+    T1CH,
+    T1LL,
+    T2LL,
+    T2CH,
+}

macroquad/Cargo.toml

@@ -5,4 +5,5 @@ edition = "2024"
 
 [dependencies]
 macroquad.workspace = true
-core = {  path = "../core" }
+core = {  path = "../core" }
+egui-macroquad = "0.17"

macroquad/src/bin/rom_only.rs

@@ -1,31 +0,0 @@
-use macroquad::prelude::*;
-use core::computers::rom_only::backplane::Backplane;
-pub struct UiState {
-    display_offset: u16,
-    current_offset: u16
-}
-
-#[macroquad::main("Rom_Only")]
-async fn main() {
-    
-    let mut backplane =  Backplane::new();
-    let mut state = UiState { display_offset: 0x00, current_offset: 0x00 };
-    
-    loop {
-        clear_background(BLUE);
-        
-        draw_text("ROM ONLY", 20.0, 20.0, 30.0, DARKGRAY);
-        
-        backplane.tick();
-
-        draw_text(
-            format!("Display Offset: 0x{:04x}", state.display_offset).as_str(), 20.0, 60.0, 30.0, DARKGRAY
-        );
-
-        draw_text(
-            format!("Current Offset: 0x{:04x}", state.current_offset).as_str(), 20.0, 100.0, 30.0, DARKGRAY
-        );
-
-        next_frame().await
-    }
-}