--- a/README.markdown Fri Dec 16 14:49:23 2016 -0500
+++ b/README.markdown Fri Dec 16 15:31:51 2016 -0500
@@ -1,3 +1,11 @@
A Chip-8 emulator in Common Lisp.
* **License:** MIT/X11
+
+
+References
+----------
+
+* http://devernay.free.fr/hacks/chip8/C8TECH10.HTM
+* http://mattmik.com/files/chip8/mastering/chip8.html
+* https://github.com/AfBu/haxe-chip-8-emulator/wiki/(Super)CHIP-8-Secrets
--- a/src/emulator.lisp Fri Dec 16 14:49:23 2016 -0500
+++ b/src/emulator.lisp Fri Dec 16 15:31:51 2016 -0500
@@ -1,20 +1,9 @@
(in-package :chip8)
-
-(setf *print-length* 16)
-(setf *print-base* 10)
-
(declaim (optimize (speed 1) (safety 3) (debug 3)))
-(declaim (optimize (speed 3) (safety 1) (debug 3)))
-
-
-;;;; Reference ----------------------------------------------------------------
-;;; http://devernay.free.fr/hacks/chip8/C8TECH10.HTM
-;;; http://mattmik.com/files/chip8/mastering/chip8.html
-;;; https://github.com/AfBu/haxe-chip-8-emulator/wiki/(Super)CHIP-8-Secrets
;;;; Constants ----------------------------------------------------------------
-(defconstant +cycles-per-second+ 300)
+(defconstant +cycles-per-second+ 500)
(defconstant +cycles-before-sleep+ 10)
(defconstant +screen-width+ 64)
(defconstant +screen-height+ 32)
@@ -29,32 +18,37 @@
;;;; Utils --------------------------------------------------------------------
-(declaim
- (inline not= +_8 -_8 chop cat-bytes get-bit bcd))
-
-(defun not= (x y)
+(defun-inline not= (x y)
(not (= x y)))
-(defun chop (size integer)
+(defun-inline chop (size integer)
(ldb (byte size 0) integer))
-(defun cat-bytes (high-order low-order)
+(defun-inline cat-bytes (high-order low-order)
(dpb high-order (byte 8 8) low-order))
-(defun get-bit (position integer)
+(defun-inline get-bit (position integer)
(ldb (byte 1 position) integer))
-(defun +_8 (x y)
+(defun-inline +_8 (x y)
(let ((result (+ x y)))
(values (chop 8 result)
(if (> result 255) 1 0))))
-(defun -_8 (x y)
+(defun-inline -_8 (x y)
(let ((result (- x y)))
(values (chop 8 result)
(if (> x y) 1 0))))
-(defun bcd (integer)
+(defun-inline >>_8 (v)
+ (values (ash v -1)
+ (get-bit 0 v)))
+
+(defun-inline <<_8 (v)
+ (values (chop 8 (ash v 1))
+ (get-bit 7 v)))
+
+(defun-inline bcd (integer)
(values (-<> integer (floor <> 100) (mod <> 10))
(-<> integer (floor <> 10) (mod <> 10))
(-<> integer (floor <> 1) (mod <> 10))))
@@ -67,9 +61,6 @@
;;;; Data ---------------------------------------------------------------------
-(declaim
- (inline chip-flag (setf chip-flag)))
-
(defstruct chip
(running t :type boolean)
(memory (make-array +memory-size+ :element-type 'int8)
@@ -80,22 +71,21 @@
:read-only t)
(index 0 :type int16)
(program-counter #x200 :type int12)
- (keys (make-array 16 :element-type 'boolean)
+ (keys (make-array 16 :element-type 'boolean :initial-element nil)
:type (simple-array boolean (16))
:read-only t)
(video (make-array (* +screen-height+ +screen-width+) :element-type 'fixnum)
:type (simple-array fixnum (#.(* +screen-height+ +screen-width+)))
:read-only t)
(video-dirty t :type boolean)
- (delay-timer 0 :type int8)
- (sound-timer 0 :type int8)
+ (delay-timer 0 :type fixnum)
+ (sound-timer 0 :type fixnum)
(stack (make-array 16 :element-type 'int12 :fill-pointer 0)
:type (vector int12 16)
:read-only t)
(loaded-rom nil :type (or null string))
(debugger (make-debugger) :type debugger :read-only t))
-
(define-with-macro chip
running
memory
@@ -108,23 +98,22 @@
debugger)
-(defun chip-flag (chip)
+(defun-inline chip-flag (chip)
(aref (chip-registers chip) #xF))
-(defun (setf chip-flag) (new-value chip)
+(defun-inline (setf chip-flag) (new-value chip)
(setf (aref (chip-registers chip) #xF) new-value))
;;;; Graphics -----------------------------------------------------------------
(declaim
- (inline font-location vref (setf vref))
(ftype (function (chip int8 int8 int4) null) draw-sprite))
-(defun vref (chip x y)
+(defun-inline vref (chip x y)
(aref (chip-video chip) (+ (* +screen-width+ y) x)))
-(defun (setf vref) (new-value chip x y)
+(defun-inline (setf vref) (new-value chip x y)
(setf (aref (chip-video chip) (+ (* +screen-width+ y) x))
new-value))
@@ -150,7 +139,7 @@
#xF0 #x80 #xF0 #x80 #x80) ; F
:start1 #x50))
-(defun font-location (character)
+(defun-inline font-location (character)
(+ #x50 (* character 5)))
@@ -218,8 +207,8 @@
nil))))
-(macro-map ;; LD ...
- ((name arglist destination source)
+(macro-map ;; LD
+ ((NAME ARGLIST DESTINATION SOURCE)
((op-ld-i<imm (_ (value 3)) index value)
(op-ld-reg<imm (_ r (value 2)) (register r) value)
(op-ld-reg<reg (_ rx ry _) (register rx) (register ry))
@@ -250,27 +239,24 @@
;; For some weird reason the ADD immediate op doesn't set the flag
(zapf (register r) (+_8 % immediate)))
-(macro-map ;; ADD/SUB (8-bit)
- ((name op source-arg source-expr)
- ((op-add-reg<reg +_8 (ry 1) (register ry))
- (op-sub-reg<reg -_8 (ry 1) (register ry))))
- `(define-opcode ,name (_ rx ,source-arg)
- (multiple-value-bind (result carry)
- (,op (register rx) ,source-expr)
- (setf (register rx) result
- flag carry))))
+(define-opcode op-add-reg<reg (_ rx ry) ;; ADD Vx, Vy (8-bit)
+ (setf (values (register rx) flag)
+ (+_8 (register rx) (register ry))))
+
+(define-opcode op-sub-reg<reg (_ rx ry) ;; SUB Vx, Vy (8-bit)
+ (setf (values (register rx) flag)
+ (-_8 (register rx) (register ry))))
(define-opcode op-add-index<reg (_ r) ;; ADD I, Vx (16-bit)
(zapf index (chop 16 (+ % (register r)))))
-(define-opcode op-subn-reg<reg (_ rx ry) ;; SUBN
- (multiple-value-bind (result carry)
- (-_8 (register ry) (register rx)) ; subtraction order is swapped for SUBN
- (setf (register rx) result
- flag carry)))
+(define-opcode op-subn-reg<reg (_ rx ry) ;; SUBN Vx, Vy (8-bit)
+ (setf (values (register rx) flag)
+ ;; subtraction order is swapped for SUBN
+ (-_8 (register ry) (register rx))))
(macro-map ;; SE/SNE
- ((name test x-arg x-form y-arg y-form)
+ ((NAME TEST X-ARG X-FORM Y-ARG Y-FORM)
((op-se-reg-imm = (r 1) (register r) (immediate 2) immediate)
(op-sne-reg-imm not= (r 1) (register r) (immediate 2) immediate)
(op-se-reg-reg = (rx 1) (register rx) (ry 1) (register ry))
@@ -280,13 +266,12 @@
(incf program-counter 2))))
(macro-map ;; AND/OR/XOR
- ((name function)
- ((op-or logior)
- (op-and logand)
- (op-xor logxor)))
+ ((NAME OP)
+ ((op-and logand)
+ (op-or logior)
+ (op-xor logxor)))
`(define-opcode ,name (_ destination source _)
- (zapf (register destination)
- (,function % (register source)))))
+ (zapf (register destination) (,op % (register source)))))
(define-opcode op-rand (_ r (mask 2)) ;; RND
(setf (register r)
@@ -321,14 +306,12 @@
(decf program-counter 2))))
(define-opcode op-shr (_ r _ _) ;; SHR
- (let ((value (register r)))
- (setf flag (get-bit 0 value)
- (register r) (ash value -1))))
+ (setf (values (register r) flag)
+ (>>_8 (register r))))
(define-opcode op-shl (_ r _ _) ;; SHL
- (let ((value (register r)))
- (setf flag (get-bit 7 value)
- (register r) (chop 8 (ash value 1)))))
+ (setf (values (register r) flag)
+ (<<_8 (register r))))
(define-opcode op-ld-font<vx (_ r _ _) ;; LD F, Vx
(setf index (font-location (register r))))
@@ -372,6 +355,7 @@
:element-type 'single-float
:initial-element 0.0))
+
(defun fill-buffer (buffer function rate start)
(iterate
(for i :index-of-vector buffer)
@@ -441,8 +425,6 @@
(ftype (function (chip) null) run-cpu emulate-cycle)
(ftype (function (chip int16) null) dispatch-instruction))
-(defparameter *c* nil)
-
(defun reset (chip)
(with-chip (chip)
@@ -530,6 +512,8 @@
;;;; Main ---------------------------------------------------------------------
+(defparameter *c* nil)
+
(defun run (rom-filename &key start-paused)
(let ((chip (make-chip)))
(setf *c* chip)
@@ -544,6 +528,3 @@
(bt:make-thread (curry #'run-timers chip))
(bt:make-thread (curry #'run-sound chip))))))
-
-;;;; Scratch ------------------------------------------------------------------
-; (run "roms/blitz.rom")