Today, 1(of8)DUMB TERMINAL appeared to be writing its own code?greenspun.com : LUSENET : TimeBomb 2000 (Y2000) : One Thread
Today, at work one of 8 networked dumb terminals seemed to decide to bug out and appeared to be just sitting there writing its own code! ( or so it appeared to my boss) I wouldnt know, dont know that much about computers. The other terminals were working fine. What could have happened?
-- Ann Fisher (firstname.lastname@example.org), December 07, 1998
That would be God. Since he has had his laughs, and he knows there's no way in hell we can do it, he is going to go ahead and fix it for us!
-- M.D. (email@example.com), December 08, 1998.
I don't know what happened but here's one likely possibility: Terminals receive data from the computer to which you are connected (i.e. the stuff that get's displayed on the screen). In addition, most terminals also support a set of 'commands' (aka control sequences). You (should) never see these commands displayed on the screen -- they are basically invisible to the user -- they are use to control where and how information is placed on the screen. For example, it might receive a sequence of data and commands that tell it to go to line 14, column 22, turn on reverse video and display the value "$1,000".
A number of things can go wrong in this process. For example, data transmission lines (the cables that go from your terminal to the computer) can have errors that occur (bad cable, somebody bumps a connector, the connector on your machine is loose, bad hardware somewhere along the route from your terminal top the computer you are eventually connected to, and so on and so forth). As a result, some of this data can be lost. If the lost or garbled data happened to be part of a control sequence, the terminal may become 'confused' and may begin actually attempting to display some of the control sequences which can look like 'code' (oddball gobbledygook characters).
When this happens you typically just need to reset your terminal. This may be as easy as switching the unit off then on again or may require some other action. Check with your system administrator for the proper procedure where you work.
Another similar situation that we see a lot happens when a user attempts to display a binary file on their screen. Basically, there are two types of ways computers store data in files: as 'text' or as 'binary' (this is an over-simplification but think of binaries as everything that isn't text - might include software programs, databases, graphics, sounds, zipped files, etc.) If you attempt to display a binary file using a command intended for a text file, you will often 'confuse' your terminal. This happens to me every once in a while on our Unix-based systems if I'm not watching what I'm doing. It used to happen A LOT under DOS when a user would enter the command "TYPE
" where contained not text but binary information.
In short, it's frustrating but really nothing to worry about.
-- Arnie Rimmer (Arnie_Rimmer@usa.net), December 08, 1998.
And when they fail, cmputers fail in weird and wonderful ways............
-- Robert A. Cook, P.E. (Kennesaw, GA) (firstname.lastname@example.org), December 08, 1998.