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From: disteli@inf.ethz.ch (Andreas Reto Disteli)
Subject: S3
Message-ID: <1993Apr16.071049.28597@neptune.inf.ethz.ch>
Sender: news@neptune.inf.ethz.ch (Mr News)
Nntp-Posting-Host: lillian-gw
Organization: Dept. Informatik, Swiss Federal Institute of Technology (ETH), Zurich, CH
Date: Fri, 16 Apr 1993 07:10:49 GMT
Lines: 40


Re: Problems with S3-initialization

As described the manual the following steps must be done for th initialization
of the S3 card.

InitDisplay;
	(*BIOS-Call
		with AX-Reg = 4F02H
		with BX-Reg = 105H for 1024 x 768 x 256 resolution
		Interrupt 10H *)
Unlock Register Lock 1 (CR38)
	(* For access to S3 Register Set *)
Unlock Register Lock 2 (CR39)
	(* For access to Syst. Control and Syst. Extension Register *)
Unlock Graphic Command Group (CR40)
	(* Set Bit 0 to 1 in Syst. Configuration Register *)
Unlock Advanced Display Functions
	(* Set Bit 0 to 1 in Function Control Register *)

After these operations the FIFO-stack of the S3 should be empty.
When we watch the status (Graph. Proc. Status), we always get
the value 0FH instead of 0H.
Full would mean 0FFH (8 places occupied), empty would mean 0H
(0 places occupied).

It is possible to read this register in two different ways. 
Both times we get different results.



Our machine is a 486 DX/2 with EISA bus and a S3 86C805 local bus. 

--> any ideas?

Andreas Disteli
Institut fuer Computersysteme, ETH Zuerich
email: disteli@inf.ethz.ch


