|
|||||
|
Browse
Prev - Item - Next PREV - Group - NEXT Peripherals Terminals o Teletype o DEC Writer o Digital VT100 o Digital VT320 o Lear Siegler o Wang o Philips X3300 o Hazeltine o Viditel terminal |
 
 
 
 
Terminals While a PC is a single user machine, many big UNIX machines, mainframes etc are not, they consist of a big system-box and are multi-user. These users also need a monitor and a keyboard connected to the machine but this done either directly via serial ports or via the network. In case of network a serial connection is provided on top of the network with special boxes, on the terminal the user first has to talk to this box to connect to one of the machines connected to the network after which he can actually login to this machine. Terminals simply put the characters
typed on the keyboard out
on the serial port and display the characters that come in on the
serial port on the
display. A few protocols are used here, the simplest being that after
every character that comes in, the cursor is places one place to the
right. When the line is full you start again
at the left, one line lower. When all lines are used you move all lines
one line up
to make room for a new line. Special characters were invented like the
linefeed and
carriage return, the tab and the form feed (clear screen). |
||||