The first step is to connect your PC to the remote computer using a serial cable. The only actual Wyse terminals I've seen, have 25-way, female, D-type connectors on the back:
Modern PCs have one 9-way, male D-type:
While older PCs often have one 25-way, male D-type:
If you have an existing serial cable, it is possible to buy plugin adapters that will convert from a 25-way, male D-type plug into a 9-way, female D-type plug suitable for most PCs:
Your friendly local computer store is a good place to buy such adapters from.
Note: sometimes a combination of a 'gender changer' and a '25-way into 9-way converter' will be required.
The alternative is to make (or buy) a suitable serial cable. The connections for the PC end should allow the use of hardware handshaking, preferably using the RTS/CTS lines. If you are going to be logging into a Unix box, the DTR line usually needs connecting so that the remote computer knows that a terminal is connected and switched on.
For completeness, here are two diagrams which show the mapping between a 25-way and a 9-way RS232 D-type connector, and the wiring for an RS232 serial cable to connect two PCs together so that hardware-handshaking works:
The second diagram uses pin numbers for a 25-way D-type, and these pin numbers and signal names match those of a Wyse Terminal (the PC and most terminals are DTE devices).
Getting serial links working correctly can be fraught with difficultly and without the use of serial line monitoring gadgets or at least a multi-meter there can often be too many unknowns for a novice.
I like to start from a known state, so I want to see a working terminal session on the cable I am going to use before wasting a lot of time.
The settings for baud-rate, parity, data bits, stop-bits, and handshaking can be read from the working terminal configuration:
All you have to do then, is use a trusty gender-changer/ 25way into 9way adapter combination and get the serial port working on the PC.
Problems I have encountered include: