[SiriusHardware]

Well, it's good that you found that. If this had been any ordinary logic IC we would have said just replace it. Unfortunately that IC is one of the PROMs, it contains factory programmed data which is specific to this model or model range so it is a chip which you can't easily 'just replace'.

Can you see if the other half of that snapped IC lead is still inside the corresponding socket hole? If it is you are going to have to get it out or remove and replace the whole socket. If you do have to replace the whole socket you could replace it with a turned-pin type, plug the chip into it and spot-solder the broken pin to the 'well' on the top of the socket contact.

If the socket hole is vacant what you can do, if you feel up to it, is to first find an unused new component like a resistor or capacitor which has leads which are a nice smooth fit in the hole in the socket, and then solder the end of one lead to the inside of the remainder of the snapped pin. Once you've got it in the right place and at the right angle, trim the lead off to the same length as the other leads on the device. The attached crude sketch illustrates what I mean.

You can also bend the original upper half of the pin inwards a bit and solder the 'new' lead to the outside of it instead. That would be easier to do but it will make the repair more obvious. You may not mind about that as long as it works.

Edit: Top tip from Tim, I've never thought about using another whole leg from a duff chip (rather than a bit of component lead) as a replacement leg. Will have to remember that one.