How can we connect multiple terminals to a single linux system, is any special hardware needed

What media (ethernet, rs-232, ppp)?

What kind of terminals?

thank you for being so prompt ,
i am not such a technical person so i will tell what i am trying to do

i want to add an extra data entry terminal to an existing pharmacy software which is running on a single cpu
only with a monitor and keyboard
without investing into another cpu

i hope this is clear
i dont know how else to explain


thanks

There used to be ISA cards which gave you, in effect, a second computer running in the PC so that you had two computers for the price of one (plus a VDU and keyboard). I haven't seen any of these around recently and doubt they are supported under Linux.

Another method was a kind of 'reversed KVM' switch which connects two VDU/keyboard/Mouse sets to one CPU. Fine provided only one user wants the machine at a time.

Given the price of machines these days, though, neither of the above seems like a good move. Surely, all you want is a second cheap machine running Linux and connect it to your main machine using a serial cable (probably set up as a null modem).

You can even run X-Windows this way, although slowly.