SA44@LIVERPOOL.AC.UK (Kevin Maguire) (05/31/90)
In article <1990May29.202056.26271@ox.com>, time@ox.com (Tim Endres) says: >I am working on an implementation of News for the lowly Macintosh. >I have had many requests to support compressed/batched news. >Most people have indicated that "compress", the PD version, is what >is normally used for news compression. This would *seem* fine, but >the darn thing requires 500K RAM just to uncompress. This not only >seems extraordinary, but I can not see how implementations on a PC >limited to 640K could even work. I had a look at the compress.c (comp.c ??) file in C news and it does indeed seem to be the standard UN*X compress(1) command incognito. It depends which defines you choose when compiling this file whether you get 16bit/12bit/whatever compression. Yes 16 bit does need ~400K to compress in but uncompressing with even 16bit need much less ~70K (?) So just get this file (compress.c) and compile in 16bit mode. Once compiled compress automatically determines the compression mode a file was compressed in so on your Mac you can compress your batches in 13 bit mode and send them out and uncompress incoming 16bit batches as well. The commandline option is "compress -b13" for thirteen bits. This way you'll only need about 70K of work space to send out 13bit batches (which any compress should automatically handle) and uncompress 16bits batches. Alternatively, ask your feed site to use 13bit (or 12) compression on your batch (don't think either C news or B news automatically allow this however :-() Kevin Maguire Nsfnet : sa44%liv.ac.uk@nsfnet-relay.ac.uk Uucp : ...!mcsun!ukc!liv-ib!sa44
henry@utzoo.uucp (Henry Spencer) (06/03/90)
In article <90151.173150SA44@LIVERPOOL.AC.UK> SA44@LIVERPOOL.AC.UK (Kevin Maguire) writes: >I had a look at the compress.c (comp.c ??) file in C news and it does >indeed seem to be the standard UN*X compress(1) command incognito. Actually, the C News distribution as shipped from here doesn't include a compressor at all; we simply assumed that everyone had compress. (We realize this isn't a safe assumption, but we have to cut things off somewhere.) >... Alternatively, ask your feed site to use 13bit (or 12) >compression on your batch (don't think either C news or B news automatically >allow this however :-() C News defaults to 12-bit compression, precisely to be compatible with small machines. In fact, you have to go in and work at it to get 16-bit compression. (That probably should be made easier.) -- As a user I'll take speed over| Henry Spencer at U of Toronto Zoology features any day. -A.Tanenbaum| uunet!attcan!utzoo!henry henry@zoo.toronto.edu