English Amiga Board


Go Back   English Amiga Board > Coders > Coders. Language > Coders. Blitz Basic

 
 
Thread Tools
Old 30 March 2018, 11:22   #21
Toni Wilen
WinUAE developer
 
Join Date: Aug 2001
Location: Hämeenlinna/Finland
Age: 43
Posts: 22,129
Great.

I think original reason was 68030 cache related bug/feature: long aligned writes always get cached if write allocate cache mode is enabled, even if write goes to hardware level (CI pin active) cache-inhibited memory. Only MMU level cache inhibit works properly in this situation.

CPU wrote something to chip ram, and because it was long and aligned write, it also got stored in data cache. Then blitter modified same memory. Finally CPU was used to read from address that was previously written to: data came from cache, not from memory that blitter modified.

EDIT: This happens very rarely because cache is so tiny.
Toni Wilen is offline  
 


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
What makes you an Amiga user? manic23 Nostalgia & memories 63 14 May 2015 23:15
Compact Flash Write Errors and Nervous Mouse merlin1968 support.Hardware 7 16 June 2013 04:01
Only Amiga makes it possible Reynolds request.Other 10 15 October 2010 05:09
Only the Amiga makes it possible... Paul_s Amiga scene 46 09 July 2009 15:57
Only Amiga makes it possible! laffer Retrogaming General Discussion 13 07 June 2007 06:50

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +2. The time now is 16:59.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2018, vBulletin Solutions Inc.
Page generated in 0.05982 seconds with 13 queries