we can type all the letters!

src/cpu.rs

@@ -2,14 +2,11 @@ use crate::error::{ExecutionError, GeorgeError, GeorgeErrorKind, MemoryError};
 use crate::instructions::{get_instruction, Instruction};
 use crate::memory::Mem;
 use crate::types::{Byte, Word};
+use std::path::PathBuf;
 use std::process::exit;
 use std::sync::Mutex;
 use std::time::Duration;
-use std::{
+use std::{str::FromStr, sync::Arc, thread::sleep};
-    str::FromStr,
-    sync::{Arc, RwLock},
-    thread::sleep,
-};
 
 #[derive(Clone, Copy)]
 pub enum StatusFlag {
@@ -67,7 +64,7 @@ impl Cpu {
                 return Err(MemoryError::NoDataAtAddress);
             } // TODO: upgrade this error type to a `GeorgeError` and make an errorkind for thread lock errors
         };
-        memory.read(address)
+        Ok(memory.read(address))
     }
     pub fn read_word(&self, address: Word) -> Result<Word, MemoryError> {
         let low_byte = self.read(address)?;
@@ -96,7 +93,7 @@ impl Cpu {
 
     pub fn pop_stack(&mut self) -> Result<Byte, ExecutionError> {
         let byte = self.read(self.stack_addr())?;
-        self.s += 0x1;
+        self.s = self.s.wrapping_add(0x1);
         Ok(byte)
     }
 
@@ -129,7 +126,7 @@ impl Cpu {
                 return Err(MemoryError::NoDataAtAddress);
             } // TODO: upgrade this error type to a `GeorgeError` and make an errorkind for thread lock errors
         };
-        memory.write(address, data)?;
+        memory.write(address, data);
         Ok(())
     }
 
@@ -252,7 +249,11 @@ impl Cpu {
                                 return;
                             }
                         };
-                        memory.dump().unwrap();
+
+                        println!("a: {a:#04x}, x: {x:#04x}, y: {y:#04x}, pc: {pc:#06x}, sp: {s:#04x}, sr: {p:#010b}, irq: {irq:?}, nmi: {nmi:?}", a = self.a, x = self.x, y = self.y, pc = self.pc, s = self.s, p = self.p, irq = self.irq, nmi = self.nmi);
+                        memory
+                            .dump(PathBuf::from_str("./cpu_dump.bin").unwrap())
+                            .unwrap();
                         exit(1);
                     }
                     _ => {

src/george.asm

@@ -1,84 +1,27 @@
 .setcpu "65C02"
-.segment "CODE"
+.include "macro.inc"
 
 ; okay so rn i wanna set up a very basic system init, and write a few subroutines to draw characters at x,y coordinates
-    n = $01 ; temporary storage for data stack operations
+n = $01 ; temporary storage for data stack operations
 
-.macro breakpoint ; $02 isn't a valid instruction, the emulator will see this and halt, dump memory contents
+key_row = $200 ; used for character lookup when key pressed
-    .byte $02
+key_col = $201
-.endmacro 
+cursor = $202
 
-.macro pop ; drops a data stack cell
+kb_row0 = $4400 ; keyboard hardware register, there are 5 more but i can just increment from here
-    inx
-    inx
-.endmacro
 
-.macro pop2 ; drops 2 data stack cells
+.segment "ROM"
-    inx
-    inx
-    inx
-    inx
-.endmacro
 
-.macro push ; push a data stack cell
+reset:
-    dex
-    dex
-.endmacro
-
-.macro push2 ; push 2 data stack cells
-    dex
-    dex
-    dex
-    dex
-.endmacro
-
-.macro push_char char ; pushes an ascii character code onto the stack
-    lda char
-    push
-    sta 0, x ; char low byte
-    stz 1, x ; char high byte
-.endmacro
-
-.macro push_coords coord_x, coord_y ; push a set of (x,y) coordinates onto the data stack
-    lda coord_x
-    push
-    sta 0, x ; low byte
-    stz 1,x ; high byte is zero
-    lda coord_y
-    push
-    sta 0,x ; same here
-    stz 1,x
-.endmacro
-
-.macro to_r ; pop the top of the stack off and save it in the return (hardware) stack: (n -- )
-    lda 1, x
-    pha
-    lda 0, x
-    pha
-    pop
-.endmacro
-
-.macro from_r ; pop the top of the return stack off and put it on the data stack: ( -- n)
-    push
-    pla
-    sta 0, x
-    pla
-    sta 1, x
-.endmacro
-
-init:
     ldx #0; initialize data stack pointer
-    jsr initdisplay
+;lda #$80
-
+;sta $200
-main:
+;adc $200
-    jsr draw
+;breakpoint
-    jmp main
 
 initdisplay:
     lda #$20
     ldy #0
-    jsr cleardisplay
-    rts
 
 cleardisplay:
     sta $6000,y
@@ -91,16 +34,89 @@ cleardisplay:
     sta $6700,y ; this goes slightly over but it's fine
     iny
     bne cleardisplay
+
+main:
+    ;jsr draw
+    jsr keyboard
+    jmp main
+
+keyboard:
+    ldy #0 ; loop through each row
+    @loop:
+        lda kb_row0, y
+        beq @skip ; if row has no key pressed, skip checking which key
+        jsr key_pressed
+        @skip:
+            iny
+            cpy #5
+            bne @loop
     rts
 
+key_pressed: ; a is loaded with the row byte
+    sty key_row ; store character row
+    inc cursor
+    pha
+    phy
+    ldy #0
+    @find_col:            ; test each row bit, store column if key pressed
+        lsr                ; test bit 7
+        bcs store_col       ; if set, go store character column
+        iny
+        cpy #8
+        bne @find_col     ; loop until we've checked each bit
+
+store_col:
+    sty key_col
+
+keymap_index:
+    push
+    lda key_col
+    stz 1, x
+    sta 0, x
+    push
+    lda #8
+    stz 1, x
+    sta 0, x
+    push
+    lda key_row
+    stz 1, x
+    sta 0, x
+    jsr mult
+    jsr plus
+    lda 0, x
+    tay
+
+do_something_w_key: ; we've stored the character position, now let's 
+    lda keymap, y
+    ldy cursor
+    sta $6000, y
+    pla
+    ply
+    rts
+
+keymap:
+    .byte "?outrew?"
+    .byte "?piygsq?"
+    .byte "a??khvd?"
+    .byte "42ljbfz?"
+    .byte "31?mncx?"
+    .byte "?????ssm"
+
 draw:
-    lda #%01000000
+;    lda #%01000000
-    bit $4400
+;    bit $4400
-    beq @1
+;    beq @1
-    push_coords #0, #0
+;    push_coords #0, #0
-    push_char #$77
+;    push_char #$77
-    jsr draw_char
+;    jsr draw_char
-    @1: 
+;    @1: 
+;    lda #%00100000
+;    bit $4400
+;    beq @2
+;    push_coords #0, #0
+;    push_char #$65
+;    jsr draw_char
+;    @2: 
     rts
 
 draw_char: ; draw a character c at (x, y) (n1: x n2: y n3: c -- )
@@ -217,6 +233,8 @@ mult: ; multiply: (n1 n2 -- n1*n2), frankly, i don't know how this works, but TO
     pop
     ply
     rts
-        
 
-.segment "VRAM"
+
+.segment "VECTOR"
+.word reset
+

src/george.config

@@ -1,12 +1,10 @@
 MEMORY {
-        RAM: start = $0000, size = $0200, type = rw, fill = true;
+        RAM: start = $0000, size = $8000, type = ro, fill = yes;
-        PROGRAM: start = $0200, size = $3E00, type = rw, fill = true;
+        ROM: start = $8000, size = $7FFC, type = ro, fill = yes;
-        CTRL: start = $4000, size = $2000, type = rw, fill = true;
+        VECTOR: start = $FFFC, size = $4, type = ro, fill = yes;
-        VRAM: start = $6000, size = $8000, type = rw, fill = true;
-        ROM: start = $E000, size = $2000, type = ro, fill = true;
     }
 
 SEGMENTS {
-        CODE: load = "PROGRAM", type = rw;
+        ROM: load = "ROM", type = ro;
-        VRAM: load = "VRAM", type = rw;
+        VECTOR: load = "VECTOR", type = ro;
     }

src/georgeencoding.txt

@@ -7,10 +7,10 @@
 #		 column #2 is the Unicode (in hex as 0xXXXX)
 #		 column #3 the Unicode name (follows a comment sign, '#')
 
-0x00	0x0295	# ʕ
+0x00    0x00	# 
-0x01	0x00B7  # Middle Dot
+0x01	0x2591  # 
-0x02	0x1D25	# ᴥ
+0x02	0x2592  # ᴥ
-0x03	0x0294	# ʔ
+0x03	0x2593  # ʔ
 0x04	0x2661	# White heart 
 0x05    0x2665	# Black heart 
 0x06	0x2B50	# White star
@@ -189,70 +189,70 @@
 0xB3	0x258D	#	
 0xB4	0x258E	#	
 0xB5	0x258F	#	
-0xB6    0x2591	#	
+0xB6    0x0295  #	
-0xB7    0x2592	#	
+0xB7    0x00B7  #	
-0xB8    0x2593  #	
+0xB8    0x1D25  #	
-0xB9	0x2596  # 
+0xB9	0x0294
-0xBA	0x2597  # 
+0xBA	0x2596  
-0xBB	0x2598  #
+0xBB	0x2597  
-0xBC	0x2599  # 
+0xBC	0x2598  
-0xBD	0x259A  # 
+0xBD	0x2599  
-0xBE	0x259B  #
+0xBE	0x259A  
-0xBF	0x259C  # 
+0xBF	0x259B  
-0xC0	0x259D	#	
+0xC0	0x259C  
-0xC1	0x259E	#	
+0xC1	0x259D	
-0xC2	0x259F	#
+0xC2	0x259E	
-0xC3    0x2190	#	
+0xC3    0x259F	
-0xC4	0x2191	#   
+0xC4	0x2190	
-0xC5	0x2192	#   
+0xC5	0x2191	
-0xC6	0x2193	#	
+0xC6	0x2192	
-0xC7	0x2B60	#	
+0xC7	0x2193	
-0xC8	0x2B61	#	
+0xC8	0x2B60	
-0xC9	0x2B62	#	
+0xC9	0x2B61	
-0xCA	0x2B63	#   
+0xCA	0x2B62	
-0xCB	0x2B80  #
+0xCB	0x2B63	
-0xCC	0x2B81  #
+0xCC	0x2B80  
-0xCD	0x2B82  #
+0xCD	0x2B81  
-0xCE	0x2B83  #
+0xCE	0x2B82  
-0xCF	0xF049	#
+0xCF	0x2B83  
-0xD0	0xF04A	#
+0xD0	0xF049	
-0xD1	0x23F3	#
+0xD1	0xF04A	
-0xD2	0xF07B	#
+0xD2	0x23F3	
-0xD3	0xF07C	#
+0xD3	0xF07B	
-0xD4	0xF114	#
+0xD4	0xF07C	
-0xD5	0xF115	#
+0xD5	0xF114	
-0xD6	0xF250	#
+0xD6	0xF115	
-0xD7	0xF251	#
+0xD7	0xF250	
-0xD8	0xF253	#
+0xD8	0xF251	
-0xD9	0xF254	#
+0xD9	0xF253	
-0xDA	0xF461	#
+0xDA	0xF254	
-0xDB	0xF016	#
+0xDB	0xF461	
-0xDC	0xF401	#
+0xDC	0xF016	
-0xDD	0x1F52E	#
+0xDD	0xF401	
-0xDE	0xF2DB	#
+0xDE	0x1F52E	
-0xDF	0xF008	#
+0xDF	0xF2DB	
-0xE0	0x25C7	#
+0xE0	0xF008	
-0xE1	0x25C8	#
+0xE1	0x25C7	
-0xE2	0x1F311	#
+0xE2	0x25C8	
-0xE3	0x1F312	#
+0xE3	0x1F311	
-0xE4	0x1F313	#
+0xE4	0x1F312	
-0xE5	0x1F314	#
+0xE5	0x1F313	
-0xE6	0x1F315	#
+0xE6	0x1F314	
-0xE7	0x1F316	#
+0xE7	0x1F315	
-0xE8	0x1F317	#
+0xE8	0x1F316	
-0xE9	0x1F318	#
+0xE9	0x1F317	
-0xEA	0xF04C	#
+0xEA	0x1F318	
-0xEB	0x2714	#
+0xEB	0xF04C	
-0xEC	0x2718	#
+0xEC	0x2714	
-0xED	0x25C6	#
+0xED	0x2718	
-0xEE	0xF15D	#
+0xEE	0x25C6	
-0xEF	0xF15E	#
+0xEF	0xF15D	
-0xF0	0xF071	#
+0xF0	0xF15E	
-0xF1	0xF449	#
+0xF1	0xF071	
-0xF2	0xF529	#
+0xF2	0xF449	
-0xF3	0xF658	#
+0xF3	0xF529	
-0xF4	0xF659 	#
+0xF4	0xF658	
-0xF5	0x0020	#
+0xF5	0xF659 		#
 0xF6	0x1f381	#	Space
 0xF7	0xf05a	#	Space
 0xF8	0xf06a	#	Space

src/instructions.rs

@@ -2063,6 +2063,7 @@ impl Opcode {
                     let byte = cpu.read(address.try_into()?)?;
                     let carry = cpu.get_flag(StatusFlag::Carry);
                     let result = cpu.a as Word + byte as Word + carry as Word;
+                    println!("{result:#04x}");
                     cpu.set_flag(StatusFlag::Carry, result > Word::from(u8::max_value()));
                     cpu.set_flag(StatusFlag::Zero, result as Byte == 0);
                     cpu.set_flag(
@@ -2073,6 +2074,7 @@ impl Opcode {
                     );
                     cpu.set_flag(StatusFlag::Negative, cpu.is_negative(result as Byte));
                     cpu.a = result as Byte;
+                    println!("{:#04x}", cpu.a);
                     Ok(())
                 }
                 _ => Err(GeorgeErrorKind::AddrMode(
@@ -2103,10 +2105,7 @@ impl Opcode {
                 fn asl(cpu: &mut Cpu, value: Byte) -> Byte {
                     cpu.set_flag(StatusFlag::Carry, value & 0b1000_0000 == 0b1000_0000);
                     let shifted_value = value << 1;
-                    cpu.set_flag(
+                    cpu.set_flag(StatusFlag::Negative, cpu.is_negative(shifted_value));
-                        StatusFlag::Negative,
-                        value & StatusFlag::Negative as Byte > 0,
-                    );
                     cpu.set_flag(StatusFlag::Zero, shifted_value == 0);
                     shifted_value
                 }
@@ -2532,7 +2531,8 @@ impl Opcode {
             Opcode::BRK(mode) => match mode {
                 AddressingMode::Implied => {
                     cpu.set_flag(StatusFlag::Brk, true);
-                    panic!("Interrupts unimplemented!");
+                    Ok(())
+                    //panic!("Interrupts unimplemented!");
                 }
                 _ => Err(GeorgeErrorKind::AddrMode(
                     AddressingModeError::IncompatibleAddrMode,
@@ -2662,6 +2662,8 @@ impl Opcode {
             Opcode::DEX(mode) => match mode {
                 AddressingMode::Implied => {
                     cpu.x = cpu.x.wrapping_sub(1);
+                    cpu.set_flag(StatusFlag::Zero, cpu.x == 0);
+                    cpu.set_flag(StatusFlag::Negative, cpu.is_negative(cpu.x));
                     Ok(())
                 }
                 _ => Err(GeorgeErrorKind::AddrMode(
@@ -2670,7 +2672,9 @@ impl Opcode {
             },
             Opcode::DEY(mode) => match mode {
                 AddressingMode::Implied => {
-                    cpu.y -= 1;
+                    cpu.y = cpu.y.wrapping_sub(1);
+                    cpu.set_flag(StatusFlag::Zero, cpu.y == 0);
+                    cpu.set_flag(StatusFlag::Negative, cpu.is_negative(cpu.y));
                     Ok(())
                 }
                 _ => Err(GeorgeErrorKind::AddrMode(
@@ -2824,11 +2828,8 @@ impl Opcode {
                 fn lsr(cpu: &mut Cpu, value: Byte) -> Byte {
                     cpu.set_flag(StatusFlag::Carry, value & 1 == 1);
                     let shifted_value = value >> 1;
-                    cpu.set_flag(
-                        StatusFlag::Negative,
-                        value & StatusFlag::Negative as Byte > 0,
-                    );
                     cpu.set_flag(StatusFlag::Zero, shifted_value == 0);
+                    cpu.set_flag(StatusFlag::Negative, cpu.is_negative(value));
                     shifted_value
                 }
                 match mode {
@@ -3048,10 +3049,7 @@ impl Opcode {
                     let carry = cpu.get_flag(StatusFlag::Carry) as Byte;
                     cpu.set_flag(StatusFlag::Carry, value >> 7 == 1);
                     let shifted_value = (value << 1) + carry;
-                    cpu.set_flag(
+                    cpu.set_flag(StatusFlag::Negative, cpu.is_negative(shifted_value));
-                        StatusFlag::Negative,
-                        shifted_value & StatusFlag::Negative as Byte > 0,
-                    );
                     cpu.set_flag(StatusFlag::Zero, shifted_value == 0);
                     shifted_value
                 }
@@ -3080,10 +3078,7 @@ impl Opcode {
                     let carry = cpu.get_flag(StatusFlag::Carry) as Byte;
                     cpu.set_flag(StatusFlag::Carry, value & 1 == 1);
                     let shifted_value = (value >> 1) + (carry << 7);
-                    cpu.set_flag(
+                    cpu.set_flag(StatusFlag::Negative, cpu.is_negative(shifted_value));
-                        StatusFlag::Negative,
-                        shifted_value & StatusFlag::Negative as Byte > 0,
-                    );
                     cpu.set_flag(StatusFlag::Zero, shifted_value == 0);
                     shifted_value
                 }

src/main.rs

@@ -9,31 +9,17 @@ mod types;
 mod video;
 
 use crate::cpu::Cpu;
-use crate::memory::{Mem, MemMappedDevice};
+use crate::memory::Mem;
 use crate::video::Crtc;
 
+use std::str::FromStr;
 use std::sync::Mutex;
-use std::{
+use std::thread::sleep;
-    path::PathBuf,
+use std::time::Duration;
-    sync::{Arc, RwLock},
+use std::{path::PathBuf, sync::Arc, thread};
-    thread,
-};
 
 fn main() {
-    let ram = MemMappedDevice::new(0x0000, 0x3FFF, 2, "ram".into());
+    let mut memory = Mem::new();
-    let control = MemMappedDevice::new(0x4000, 0x5FFF, 4, "control".into());
-    let vram = MemMappedDevice::new(0x6000, 0xDFFF, 1, "vram".into());
-    let rom = MemMappedDevice::new(0xE000, 0xFFFF, 4, "rom".into());
-    let mut memory = Mem::new(ram);
-    if let Err(error) = memory.add_area(control) {
-        println!("Error adding vram: {:?}", error.desc);
-    };
-    if let Err(error) = memory.add_area(vram) {
-        println!("Error adding vram: {:?}", error.desc);
-    };
-    if let Err(error) = memory.add_area(rom) {
-        println!("Error adding rom: {:?}", error.desc);
-    };
     let binary = match std::fs::File::open(PathBuf::from(
         "/Users/kline/projects/winter/george-emu/src/george",
     )) {
@@ -43,8 +29,10 @@ fn main() {
     if let Err(error) = memory.read_from_bin(binary) {
         println!("{:?}", error);
     };
-    memory.write(0xFFFC, 0x00).unwrap();
+
-    memory.write(0xFFFD, 0x02).unwrap();
+    memory
+        .dump(PathBuf::from_str("./coredump.bin").unwrap())
+        .unwrap();
 
     let shared_memory = Arc::new(Mutex::new(memory));
     let cpu_memory = shared_memory.clone();
@@ -57,5 +45,4 @@ fn main() {
     });
     let mut screen = Crtc::new(display_memory);
     screen.run();
-    shared_memory.lock().unwrap().dump().unwrap();
 }

src/memory.rs

@@ -1,124 +1,44 @@
-use crate::error::{GeorgeError, GeorgeErrorKind, MappingError, MemoryError};
+use crate::error::MemoryError;
 use crate::types::{Byte, Word};
 use std::io::{self, Write};
 use std::path::PathBuf;
+use std::u16;
 use std::{fs::File, io::Read};
 
-#[derive(Debug, Clone)]
-pub struct MemMappedDevice {
-    start: Word,
-    end: Word,
-    pages: usize,
-    page: usize,
-    data: Vec<Byte>,
-    label: String,
-}
-
-impl MemMappedDevice {
-    pub fn new(start: Word, end: Word, pages: usize, label: String) -> Self {
-        Self {
-            start,
-            end,
-            pages,
-            page: 0,
-            data: vec![0x00; (end as usize + 1 - start as usize) * pages],
-            label,
-        }
-    }
-    fn contains(&self, address: Word) -> bool {
-        self.start <= address && self.end >= address
-    }
-    fn swap_page(&mut self, page: usize) -> Result<(), GeorgeError> {
-        match page > self.pages {
-            true => Err(GeorgeError {
-                kind: GeorgeErrorKind::Memory(MemoryError::Unmapped), //TODO: should be MappingError::InvalidPage,
-                desc: format!(
-                    "{:?} tried to swap to a page outside of its range",
-                    self.label
-                ),
-            }),
-            false => {
-                self.page = page;
-                Ok(())
-            }
-        }
-    }
-    fn size(&self) -> Word {
-        self.end - self.start + 1
-    }
-    fn translate_address(&self, address: Word) -> Word {
-        (address - self.start) + self.size() * (self.page as Word)
-    } // This needs to translate memory address from CPU land to local land, so
-      // for rom an address like 0xFFFF needs to be translated to Page X, 0xFFF
-}
-
 #[derive(Debug, Clone)]
 pub struct Mem {
-    areas: Vec<MemMappedDevice>,
+    pub data: Vec<Byte>,
 }
 
 impl Mem {
-    pub fn new(area: MemMappedDevice) -> Self {
+    pub fn new() -> Self {
-        Self { areas: vec![area] }
+        Self {
-    }
+            data: vec![0; u16::MAX as usize + 1],
-    pub fn dump(&self) -> io::Result<()> {
-        let mut outfile = File::create("./coredump.bin")?;
-        let mut data = Vec::new();
-        for area in &self.areas {
-            for byte in &area.data {
-                data.push(byte.to_owned());
-            }
         }
-        outfile.set_len(0xFFFF)?;
+    }
-        outfile.write_all(&data)?;
+    pub fn dump(&self, path: PathBuf) -> io::Result<()> {
+        let mut outfile = File::create(path)?;
+        outfile.write_all(&self.data)?;
         Ok(())
     }
-    pub fn add_area(&mut self, area: MemMappedDevice) -> Result<(), GeorgeError> {
-        for existing_area in &self.areas {
-            if existing_area.contains(area.end) || existing_area.contains(area.start) {
-                return Err(GeorgeError {
-                    desc: format!(
-                        "Tried to assign an area already allocated to {:?}",
-                        existing_area
-                    ),
-                    kind: GeorgeErrorKind::Mapping(MappingError::RegionOccupied),
-                });
-            }
-        }
-        self.areas.push(area);
-        Ok(())
-    }
-    pub fn read(&self, address: Word) -> Result<Byte, MemoryError> {
-        for area in &self.areas {
-            if area.contains(address) {
-                let translated_address = area.translate_address(address);
-                match area.data.get(translated_address as usize) {
-                    Some(data) => return Ok(*data),
-                    None => return Err(MemoryError::NoDataAtAddress),
-                }
-            }
-        }
-        Err(MemoryError::Unmapped)
-    }
 
-    pub fn write(&mut self, address: Word, data: Byte) -> Result<(), MemoryError> {
+    pub fn read(&self, address: Word) -> Byte {
-        for area in self.areas.iter_mut() {
+        self.data[address as usize]
-            if area.contains(address) {
+    }
-                // println!("Writing to area {label}", label = area.label);
+
-                let translated_address = area.translate_address(address);
+    pub fn write(&mut self, address: Word, data: Byte) {
-                area.data[translated_address as usize] = data;
+        self.data[address as usize] = data;
-                return Ok(());
-            };
-        }
-        Err(MemoryError::Unmapped)
     }
 
     pub fn read_from_bin(&mut self, f: File) -> Result<(), MemoryError> {
         let bytes = f.bytes();
         for (address, byte) in bytes.enumerate() {
             match byte {
-                Ok(value) => self.write(address as Word, value)?,
+                Ok(value) => self.write(address as Word, value),
-                Err(_) => return Err(MemoryError::Unwritable),
+                Err(_) => {
+                    println!("couldn't write byte {:#04x}", address);
+                    return Err(MemoryError::Unwritable);
+                }
             }
         }
         Ok(())

src/video.rs

@@ -3,7 +3,7 @@ use minifb::{Key, Scale, ScaleMode, Window, WindowOptions};
 use std::{
     fs::File,
     io::Read,
-    sync::{Arc, Mutex, RwLock},
+    sync::{Arc, Mutex},
     thread::sleep,
     time::{Duration, Instant},
 };
@@ -59,7 +59,7 @@ impl Crtc {
                 return;
             }
         };
-        let hw_ctrl = memory.read(0x4000).unwrap();
+        let hw_ctrl = memory.read(0x4000);
         match hw_ctrl & 0b0000_1000 == 0b0000_1000 {
             false => {
                 // the rest of this function is arcane wizardry based on the specifics of george's weird
@@ -67,7 +67,7 @@ impl Crtc {
                 let mut i = 0;
                 for char_row in 0..29 {
                     for char_col in 0..64 {
-                        let ascii = memory.read(0x6000 + i).unwrap();
+                        let ascii = memory.read(0x6000 + i);
                         i += 1;
                         for row in 0..13 {
                             let byte = self.char_rom[ascii as usize + (row * 0x101)];
@@ -88,7 +88,7 @@ impl Crtc {
                 for addr in 0x6000..0xBF00 {
                     // TODO: eventually this will access memory in the weird interleaved way the hardware is
                     // designed, but this is easiest to implement for now
-                    let byte = memory.read(addr).unwrap();
+                    let byte = memory.read(addr);
                     for i in 0..8 {
                         match byte & 0x80 >> i == 0 {
                             true => self.buffer[(addr - 0x6000) as usize * 8 + i] = BG_COLOR,
@@ -165,12 +165,12 @@ impl Crtc {
 
             match &mut self.memory.lock() {
                 Ok(memory) => {
-                    memory.write(0x4400, row0).unwrap();
+                    memory.write(0x4400, row0);
-                    memory.write(0x4401, row1).unwrap();
+                    memory.write(0x4401, row1);
-                    memory.write(0x4402, row2).unwrap();
+                    memory.write(0x4402, row2);
-                    memory.write(0x4403, row3).unwrap();
+                    memory.write(0x4403, row3);
-                    memory.write(0x4404, row4).unwrap();
+                    memory.write(0x4404, row4);
-                    memory.write(0x4405, row5).unwrap();
+                    memory.write(0x4405, row5);
                 }
                 Err(error) => println!("{error}"),
             }