Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 UW 5/3/83; site uw-beaver Path: utzoo!watmath!clyde!burl!ulysses!mhuxl!ihnp4!drutx!houxe!hogpc!houti!ariel!vax135!cornell!uw-beaver!info-mac From: info-mac@uw-beaver.UUCP Newsgroups: fa.info-mac Subject: Re: MacPaint -> Press Message-ID: <1275@uw-beaver> Date: Fri, 27-Jul-84 02:49:31 EDT Article-I.D.: uw-beave.1275 Posted: Fri Jul 27 02:49:31 1984 Date-Received: Sun, 22-Jul-84 03:17:29 EDT Sender: daemon@uw-beave Organization: U of Washington Computer Science Lines: 36 From: Ed Pattermann I have written a program called MACaid which converts MACINTOSH files to IMPRESS format (for IMAGEN printers). It has a few bells and whistles to be added yet, but all in all, it works. For those interested, here is a description of the format of MACpaint files. This format is the common interchange format for full-page bitmap images on the MACintosh. The first 512 bytes of the file are the header. The first four bytes comprise the version number, followed by 38*8 = 304 bytes of patterns. The remaining 204 bytes of the header are reserved for future expansion. If the version number is zero, the patterns are ignored. Hence, programs that wish to create files to be read into MACpaint can just write out 512 bytes of zero as the header. Following the header are 720 compressed scanlines of data which form the 576 wide by 720 tall bitmap. The bitmap is compressed as follows ; Any run of three or more equal bytes is compressed into a count byte and a single data byte. Runs of unequal bytes are passed on literally, preceded also by a count byte. I.E. count = -1..-127 --> replicate byte 2..128 times count = 0.. 127 --> copy 1..128 bytes uncompressed count = -128 ignored for backward compatibility That's it. A nice simple scheme. Thanks to Bill Atkinson for providing this info. I have used the new MACTERMINAL Beta Release (version .5) to upload MAC files to our 2060 via the MODEM7 protocol. It all works very well. If anyone is interested, I will make a copy of MACaid available on the INFO-MAC directory once it is ready for distribution. It is a TOPS20 program written in Rutgers Pascal. -- Ed -------