From 36a07314830fc30a10c858f16601b0847dd0bd20 Mon Sep 17 00:00:00 2001
From: BigEd <ed.spittles@gmail.com>
Date: Sun, 21 Aug 2011 21:52:22 +0100
Subject: [PATCH] memory model: remove blist dependency, model just 256k memory
for 32bit address space
---
src/py65/memory.py | 24 ++++++++++--------------
1 file changed, 10 insertions(+), 14 deletions(-)
diff --git a/src/py65/memory.py b/src/py65/memory.py
index 2f86d8b..1f19423 100644
--- a/src/py65/memory.py
+++ b/src/py65/memory.py
@@ -1,20 +1,11 @@
-# this sparse array module only needed for large-memory CPU models
-try:
- from blist import *
-except ImportError:
- pass
-
class ObservableMemory:
def __init__(self, subject=None, addrWidth=16):
+ self.physMask = 0xffff
+ if addrWidth > 16:
+ # even with 32-bit address space, model only 256k memory
+ self.physMask = 0x3ffff
if subject is None:
- if addrWidth <= 16:
- subject = 0x10000 * [0x00]
- else:
- try:
- subject = blist([0]) * (1 << addrWidth)
- except:
- print "Fatal: failed to initialise large memory for this CPU"
- exit (1)
+ subject = (self.physMask+1) * [0x00]
self._subject = subject
@@ -22,6 +13,7 @@ class ObservableMemory:
self._write_subscribers = {}
def __setitem__(self, address, value):
+ address &= self.physMask
callbacks = self._write_subscribers.get(address, [])
for callback in callbacks:
@@ -32,6 +24,7 @@ class ObservableMemory:
self._subject[address] = value
def __getitem__(self, address):
+ address &= self.physMask
callbacks = self._read_subscribers.get(address, [])
final_result = None
@@ -50,15 +43,18 @@ class ObservableMemory:
def subscribe_to_write(self, address_range, callback):
for address in address_range:
+ address &= self.physMask
callbacks = self._write_subscribers.setdefault(address, [])
if callback not in callbacks:
callbacks.append(callback)
def subscribe_to_read(self, address_range, callback):
for address in address_range:
+ address &= self.physMask
callbacks = self._read_subscribers.setdefault(address, [])
if callback not in callbacks:
callbacks.append(callback)
def write(self, start_address, bytes):
+ start_address &= self.physMask
self._subject[start_address:start_address+len(bytes)] = bytes