From f1dc5c51237458f523d22c84bf07a1f39f91af75 Mon Sep 17 00:00:00 2001 From: Syndamia Date: Sat, 24 Sep 2022 21:46:44 +0300 Subject: Renamed 6502 filename --- 6502.lisp | 66 ------------------------------------------------------------ MOS6502.lisp | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 66 insertions(+), 66 deletions(-) delete mode 100644 6502.lisp create mode 100644 MOS6502.lisp diff --git a/6502.lisp b/6502.lisp deleted file mode 100644 index e04c562..0000000 --- a/6502.lisp +++ /dev/null @@ -1,66 +0,0 @@ -;;;; Processor - -;;; Processor function -;;; -;;; Each time the *CPU* is called, it executes one operation, meaning it reads the -;;; next value in *M*, when an opcode, it either executes it, or if the opcode -;;; needs a value, gets ready to read it from the next address and do something -;;; -;;; The implementation uses closures for the internal registers. -(defparameter *CPU* (let ((PC 0) (AC 0) (X 0) (Y 0) (SR 0) (SP 0)) #'(lambda () - (let ((mval (nth PC *M*))) - (if (eql mval +OP_BRK+) - () - (if (eql mval +OP_ORAxi+) - ())))))) - -;;; External memory, where the zero page, stack and general purpose memory resides -;;; Another file has to implement it. -(defvar *M*) - -;;; Processor opcodes -;;; Ends with a small letter, depending on address mode: -;;; ac | accumulator -;;; a | absolute -;;; ax | absolute, X-indexed -;;; ay | absolute, Y-indexed -;;; d | immediate -;;; | implied -;;; i | indirect -;;; xi | X-indexed, indirect -;;; iy | indirect, Y-indexed -;;; r | relative -;;; z | zeropage -;;; zx | zeropage, X-indexed -;;; zy | zeropage, Y-indexed -(defconstant +OP_BRK+ #x00) -(defconstant +OP_ORAxi+ #x01) -(defconstant +OP_ORAz+ #x05) -(defconstant +OP_ASLz+ #x06) -(defconstant +OP_PHP+ #x08) -(defconstant +OP_ORAd+ #x09) -(defconstant +OP_ASLac+ #x0A) -(defconstant +OP_ORAa+ #x0D) -(defconstant +OP_ASLa+ #x0E) - - -(defconstant +OP_BPLr+ #x10) -(defconstant +OP_ORAiy+ #x11) -(defconstant +OP_ORAzx+ #x15) -(defconstant +OP_ASLzx+ #x16) -(defconstant +OP_CLC+ #x18) -(defconstant +OP_ORAay+ #x19) -(defconstant +OP_ORAax+ #x1D) -(defconstant +OP_ASLax+ #x1E) - -(defconstant +OP_JSRa+ #x20) -(defconstant +OP_ANDxi+ #x21) -(defconstant +OP_BITz+ #x24) -(defconstant +OP_ANDz+ #x25) -(defconstant +OP_ROLz+ #x26) -(defconstant +OP_PLP+ #x28) -(defconstant +OP_ANDd+ #x29) -(defconstant +OP_ROLac+ #x2A) -(defconstant +OP_BITa+ #x2C) -(defconstant +OP_ANDa+ #x2D) -(defconstant +OP_ROLa+ #x2E) diff --git a/MOS6502.lisp b/MOS6502.lisp new file mode 100644 index 0000000..e04c562 --- /dev/null +++ b/MOS6502.lisp @@ -0,0 +1,66 @@ +;;;; Processor + +;;; Processor function +;;; +;;; Each time the *CPU* is called, it executes one operation, meaning it reads the +;;; next value in *M*, when an opcode, it either executes it, or if the opcode +;;; needs a value, gets ready to read it from the next address and do something +;;; +;;; The implementation uses closures for the internal registers. +(defparameter *CPU* (let ((PC 0) (AC 0) (X 0) (Y 0) (SR 0) (SP 0)) #'(lambda () + (let ((mval (nth PC *M*))) + (if (eql mval +OP_BRK+) + () + (if (eql mval +OP_ORAxi+) + ())))))) + +;;; External memory, where the zero page, stack and general purpose memory resides +;;; Another file has to implement it. +(defvar *M*) + +;;; Processor opcodes +;;; Ends with a small letter, depending on address mode: +;;; ac | accumulator +;;; a | absolute +;;; ax | absolute, X-indexed +;;; ay | absolute, Y-indexed +;;; d | immediate +;;; | implied +;;; i | indirect +;;; xi | X-indexed, indirect +;;; iy | indirect, Y-indexed +;;; r | relative +;;; z | zeropage +;;; zx | zeropage, X-indexed +;;; zy | zeropage, Y-indexed +(defconstant +OP_BRK+ #x00) +(defconstant +OP_ORAxi+ #x01) +(defconstant +OP_ORAz+ #x05) +(defconstant +OP_ASLz+ #x06) +(defconstant +OP_PHP+ #x08) +(defconstant +OP_ORAd+ #x09) +(defconstant +OP_ASLac+ #x0A) +(defconstant +OP_ORAa+ #x0D) +(defconstant +OP_ASLa+ #x0E) + + +(defconstant +OP_BPLr+ #x10) +(defconstant +OP_ORAiy+ #x11) +(defconstant +OP_ORAzx+ #x15) +(defconstant +OP_ASLzx+ #x16) +(defconstant +OP_CLC+ #x18) +(defconstant +OP_ORAay+ #x19) +(defconstant +OP_ORAax+ #x1D) +(defconstant +OP_ASLax+ #x1E) + +(defconstant +OP_JSRa+ #x20) +(defconstant +OP_ANDxi+ #x21) +(defconstant +OP_BITz+ #x24) +(defconstant +OP_ANDz+ #x25) +(defconstant +OP_ROLz+ #x26) +(defconstant +OP_PLP+ #x28) +(defconstant +OP_ANDd+ #x29) +(defconstant +OP_ROLac+ #x2A) +(defconstant +OP_BITa+ #x2C) +(defconstant +OP_ANDa+ #x2D) +(defconstant +OP_ROLa+ #x2E) -- cgit v1.2.3