Fix the stupid tetris input bug
Apparently ADD Reg, Imm doesn't set the carry flag like all the
other ADD/SUB instructions.
| author |
Steve Losh <steve@stevelosh.com> |
| date |
Thu, 15 Dec 2016 19:45:03 -0500 |
| parents |
92440a7b350b
|
| children |
2dd99e07f368
|
| branches/tags |
(none) |
| files |
src/emulator.lisp |
Changes
--- a/src/emulator.lisp Thu Dec 15 19:44:28 2016 -0500
+++ b/src/emulator.lisp Thu Dec 15 19:45:03 2016 -0500
@@ -2,6 +2,7 @@
(setf *print-length* 16)
(setf *print-base* 10)
+
(declaim (optimize (speed 1) (safety 3) (debug 3)))
(declaim (optimize (speed 3) (safety 1) (debug 3)))
@@ -13,7 +14,7 @@
;;;; Constants ----------------------------------------------------------------
-(defconstant +cycles-per-second+ 500)
+(defconstant +cycles-per-second+ 1000)
(defconstant +cycles-before-sleep+ 10)
(defconstant +screen-width+ 64)
(defconstant +screen-height+ 32)
@@ -445,10 +446,13 @@
(define-opcode op-ret () ;; RET
(setf program-counter (vector-pop stack)))
+(define-opcode op-add-reg<imm (_ r (immediate 2)) ;; ADD Vx, Imm
+ ;; 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<imm +_8 (immediate 2) immediate)
- (op-add-reg<reg +_8 (ry 1) (register ry))
+ ((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)
@@ -737,3 +741,5 @@
(bt:make-thread (curry #'run-cpu chip))
(bt:make-thread (curry #'run-timers chip))
(bt:make-thread (curry #'run-sound chip))))))
+
+; (run "roms/blitz.rom")