From owner-freebsd-hackers Sun Jun 22 16:55:09 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.5/8.8.5) id QAA28794 for hackers-outgoing; Sun, 22 Jun 1997 16:55:09 -0700 (PDT) Received: from aak.anchorage.net (ai-136.anchorage.net [207.14.72.136]) by hub.freebsd.org (8.8.5/8.8.5) with ESMTP id QAA28788 for ; Sun, 22 Jun 1997 16:55:05 -0700 (PDT) Received: from localhost (abc@localhost) by aak.anchorage.net (8.8.5/8.8.5) with SMTP id PAA15600 for ; Sun, 22 Jun 1997 15:43:36 -0800 (AKDT) X-Authentication-Warning: aak.anchorage.net: abc owned process doing -bs Date: Sun, 22 Jun 1997 15:43:36 -0800 (AKDT) From: Steve Howe X-Sender: abc@aak.anchorage.net To: freebsd-hackers Subject: direct access Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk i wanted to port a hex/block editor from DOS. it can read/write 1 RAM blocks 2 Port Addresses 3 Hard/Floppy Drives 4 Files however, i am finding even simple things like ... ///////////////////////////////////////////////// int main (void) { unsigned char * p = (unsigned char *)0x000b8000; while ( 1 ) { printf("%c", *p++); getch(); } return 0; } ///////////////////////////////////////////////// where i try to read the CGA/VGA screen, bomb with "segmentation violation" errors. is the kernel examining op codes on the run, or what? is it at all possible to write Device editors? at any level of coding? ------------------------------------------------- FingerPrint BA09868C 1B995204 58410FD3 A5E7B2DA http://www.geocities.com/siliconvalley/way/7747 -------------------------------------------------