From mboxrd@z Thu Jan 1 00:00:00 1970 From: andreas.kahari@icm.uu.se (Andreas Kusalananda =?iso-8859-1?B?S+Ro5HJp?=) Date: Mon, 18 Sep 2017 12:39:11 +0200 Subject: [TUHS] And now ... Weirdnix? In-Reply-To: <201709180831.v8I8V6LB021088@freefriends.org> References: <8AA943A2-D6C0-4812-9C16-C09D1298754F@tuhs.org> <20170917144909.DB27FA585CB@yagi.h-net.msu.edu> <201709180831.v8I8V6LB021088@freefriends.org> Message-ID: <20170918103911.2bok6nfjpbbm6cqq@client.local> (This is a copy of an email I sent from the wrong address. If the first (identaical) version of the message eventually arrives, just ignore it) On Mon, Sep 18, 2017 at 02:31:06AM -0600, arnold at skeeve.com wrote: > That Pr1me had a Unix emulation layer is news to me (I think). I worked > on the Georgia Tech Software Tools Subsystem for Pr1me Computers for > several years. (Oh, how I wish I had saved that last release tape!!!) > > Primos was a terribly weird OS, but the SWT subsystem made it almost > Unix-like and very pleasant and usable. The mark parity business > was only one of the weirdnesses of that machine. Georgia Tech even > had a C compiler for it. sizeof(char) was 1, of course, but it was 16 > bits, because the instruction mode used didn't have 8 bit byte pointers. > > I can't claim credit for GT-SWT; I came along after it was mature > and stable, but I did do a few nice things. > > Arnold > > Nigel Williams wrote: [cut] I've been wondering about this for some time, if a byte isn't 8 bits on an architecture, how would you go about calculating memory sizes in a way that makes it comparable between machines? A 32 KB memory buffer is 262144=32*1024*8 bits on one machine, but 294912=32*1024*9 bits on another. That's a difference of 32 Kbit. Of course, it may not matter since both buffers contains as many items/bytes, but for the machine as a whole you can't say "this machine has X MB of memory" without mentioning the byte length. A machine with "n" bit words would be able to "store less information" in memory than a machine with the same number of MB of RAM but with "n+x" bit words. How would you do for even more exotic hardware? What if sizeof(char) != 1 for example? Maybe this isn't/wasn't an issue at all? Cheers, Kusalananda -- Andreas Kusalananda Kähäri, National Bioinformatics Infrastructure Sweden (NBIS), Uppsala University, Sweden.