Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site fritz.UUCP Path: utzoo!watmath!clyde!bonnie!akgua!whuxlm!harpo!decvax!decwrl!greipa!pesnta!pertec!felix!fritz!zemon From: zemon@fritz.UUCP (Art Zemon) Newsgroups: net.dcom Subject: Re: info on micom dataswitches??? Message-ID: <2872@fritz.UUCP> Date: Thu, 30-May-85 16:02:21 EDT Article-I.D.: fritz.2872 Posted: Thu May 30 16:02:21 1985 Date-Received: Sun, 2-Jun-85 00:28:49 EDT References: <1359@amd.UUCP> Organization: FileNet Corp., Costa Mesa, Ca. Lines: 100 Summary: personal experiences with Micom equipment I am system manager for a shop which includes a Micom Micro600 (dataswitch) and a couple different kinds of multiplexors. I thought I would respond to Phil's comments point by point. If I can provide further information, just ask. In article <> phil@amd.UUCP (Phil Ngai) writes: > >I have seen a Micom data switch (the 600 series, I think) and it had >some good points and some bad points. Good points included a claimed >high throughput and low delay. The Micro600 will support something like 592 simultaneous 9600 baud connections. The number of I/O connections to it can far exceed 592. The delay is necessarily low because the Z80 has to cycle through all the connections every 1/9600th of a second checking for bits. > Also the administrator can put in some >fairly verbose messages. There is a single 1000 byte welcome message. There is also a small set of 29 (yes, only twenty-nine) character messages which are typically used for things like "foovax down until noon". > Bad points are a top speed of 9600 (no 19200) >and pretty old technology. Configuration is done by asking the factory >to burn you a new PROM, or you can make changes in battery backed RAM. >No EEROM configuration. Top speed is indeed 9600 baud. Configuration can be done yourself if you have a PROM programmer. The PROM is all binary information but I have a C program which will let you build one without much trouble. Just upload the factory default and modify it. Then download it into a new pair of 2732s. I will be glad to provide source to my C program to any interested parties. The only condition is that you send any modifications back to me. I typically do quick reconfigurations via the command console (into the battery backed RAM) and then punch a new PROM at my convenience. It only takes about 10 minutes but you have to shut down the entire M600 to pull the memory board. Note that the I/O cards (called "quad-cards") can be changed with power on and the switch running. > The thing is big, sucks lots of power and generates >lots of heat. It seems to like being in a machine room environment. It is pretty big, about the size of a thin refrigerator. You can't get much smaller however given the large number of DB-25 sockets that you need if you fill the M600 to capacity. I don't know about environmental preferences since ours has always sat in the machine room. >If you have a campus environment where you can run twisted pair which >can operate at T1 rates, then distribution to different buildings is >pretty good. If you can only get 9600 baud links or 19200 links, the >cost per line goes up a lot, plus you have to buy the modems or line >drivers. They do have a stat mux on a card which helps hold the cabling >mess for remote sites. The M600 is the "heart" of Micom's local area non-Ethernet network. Micom makes a large number of multiplexors (both time-division and statistical) ranging from 4 to 128 lines. Most of these are available either as standalone units or as cards for the M600. Micom also just bought Interlan so it now can provide Ethernet networks as well. I don't know how well they will integrate the two product lines, however. > Support for attaching either DTE or DCE seems >reasonable, and the description of the RS-232 protocol used is among >the best I have seen. It does not appear capable of sending a break, >unlike some other equipment I have used. The M600 can indeed pass breaks through. It also acts on them under certain conditions (programmable, of course). We use breaks like this: Individual breaks typed at a terminal are transmitted to the computer. If three breaks are typed at a terminal within three seconds then then M600 drops the connection (useful if the computer crashes but otherwise never used). The M600 also drops the connection if a single break is received from the computer. I use the latter to drop connections automatically on logout; GETTY has been modified to transmit a break before putting "login:" on the screen. > They have a group termination >option (comes out in telco 25 pair connectors) which can really help >with cabling, assuming you are not scared of punch down blocks. You can also get telco connectors on one end and DB-25 connectors on the other. Of course, since you can have bare wire on one end you can do whatever you want with it; punch down blocks are not a necessity if you don't like them. -- -- Art Zemon FileNet Corp. ...! {decvax, ihnp4, ucbvax} !trwrb!felix!zemon