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Path: utzoo!utgpu!water!watmath!clyde!burl!codas!killer!sampson
From: sampson@killer.UUCP
Newsgroups: comp.sys.m6809
Subject: Re: GF9 Draft
Message-ID: <2267@killer.UUCP>
Date: Mon, 30-Nov-87 21:44:14 EST
Article-I.D.: killer.2267
Posted: Mon Nov 30 21:44:14 1987
Date-Received: Fri, 4-Dec-87 01:24:22 EST
References: <1987Nov27.110848.13005@lsuc.uucp>
Organization: The Unix(R) Connection, Dallas, Texas
Lines: 93



> TITLE: Proposal for Graphics File Format Standard

> For OS-9 / Color Computer Users

>

>      I've been waiting for a while now for some sort of standard

> to arise, but nothing has happened.  As such, this is what I'm

 

Change to:

 

, but nothing has happened except the Compuserve GIF protocol, which 

has no animation facilities.

 

> The Header Format:

>

>     The key is 64 bytes which are, for the most, to be thought

> of as 32 "words".  Where a word is 16 bits.  These 32 words make

> up the header.  There is no "tail" information defined at this

> time.

 

Problems:

 

1.  Byte swapping allowed? (e.g. Intel, ATT) or is Motorolla the format.

2.  32 "words"?  How about the three byte length and 1 byte modes, etc.

 

Would a C structure look like this:

 

typedef unsigned short word;

typedef char byte;

 

struct	header	{

	byte	Mode;

	byte	SubMode;

	byte	CompType;

	byte	Length[3];		/* Length[0] = Msb, Length[2] = Lsb */

	word	Duration;

	byte	ColorCycle[4];

	byte	Extra[20];

	word	Palette[16];		/* Actually pointers but hardcoded   */

};					/* to 16 bit addresses		     */

 

 

Wouldn't it be easier to code if Length[3] is just made a 'long':

 

	long	Length;

	byte	Extra[19];

 

/* EOF */