gilgalad@caen.engin.umich.edu (Ralph Seguin) (10/03/90)
Hi. I am about to acquire a PLEXUS 68000 based UNIX box running Sys V.2 (yech, I know 8-). I have several questions. 1: Can I get something akin to DNET to compile on this beast? 2: Can I get an ethernet board for it? 3: It has 8 serial ports, so I'm hoping to get SLIP on it. 4: Any other info anybody may have about this box. I know that DNET won't compile since V.2 doesn't have sockets. Thanks, Ralph gilgalad@dip.eecs.umich.edu gilgalad@zip.eecs.umich.edu gilgalad@caen.engin.umich.edu Ralph_Seguin@ub.cc.umich.edu gilgalad@sparky.eecs.umich.edu USER6TUN@UMICHUB.BITNET Ralph Seguin | Drinking a pan-galactic gargle blaster is 536 South Forest | like being struck over the head by a large Apartment 915 | brick of gold with a lemon wrapped around it. Ann Arbor, MI 48104 | - Zaphod Beeblebrox (313) 662-4805
david@twg.com (David S. Herron) (10/06/90)
In article <1990Oct3.043213.18022@caen.engin.umich.edu> gilgalad@caen.engin.umich.edu (Ralph Seguin) writes: >Hi. I am about to acquire a PLEXUS 68000 based UNIX box running >Sys V.2 (yech, I know 8-). I have several questions. >1: Can I get something akin to DNET to compile on this beast? Not very likely .. the reason DNET requires sockets is so that it can avoid the "blocking" (i.e. hang-until-a-character-arrives) that normally happens on Unix. There normally isn't a way to specify that an I/O channel is able to do asynchronous reads or writes in Unix .. arguably a lack in its design. The way select() helps is that it lets the program check the port without hanging, or to hang for a little while, or to return when *any* I/O descriptor has characters or any reasonable combination of the above. System V has never had this, except through add-in packages from various vendors (ahem) add-in TCP/IP packages :-). System V r4 will (I think, haven't read the docs on it yet) have a socket interface in the native system. But that's neither here nor there .. SysVr2 simply didn't have anything similar. In r3+streams you have this system call which looks promising: poll(). But it only works on a "stream", and doesn't work on a real tty device even though the tty drivers had become streams based. The interface at the /dev/ttynn level had gotten the streams-isms stripped away, I suppose. Sigh.. The closest you get with r2 is to set the VTIM type parameters using stty (or ioctl() if you're speaking C at the OS). >2: Can I get an ethernet board for it? mebbe tho it might be a bit hard to find one since that machine probably isn't in production ... >3: It has 8 serial ports, so I'm hoping to get SLIP on it. Plan on porting TCP/IP on your own. If'n you do port it on your own you can maybe shove a real select() into it. On the other hand I've read through the source for TWG/TCP for 7300/3b1's (a SysVr2 box based on 68010, should be some similarity to your Plexus) .. All the code for doing select() on a tty is commented out -- I haven't read closely enough to see *why* but I suspect that some niggling detail in the kernel architecture on SysV doesn't support this. I would suggest working back and forth between Bach's book on SysV internals and Karels book on 4.3BSD internals ;-). Hope this helps ... [response is in public since I've seen other similar queries in the past] David -- <- David Herron, an MMDF & WIN/MHS guy, <david@twg.com> <- Formerly: David Herron -- NonResident E-Mail Hack <david@ms.uky.edu> <- <- Remember: On System V it's "tar xovf", not "tar xvf"!