| count listener |
    count _ 0.
    listener _ ComancheListener
        on: 8123
        handler: 
            [ :socket |
            count _ count + 1.
            Transcript show: socket getData.
            socket closeAndDestroy].
    listener forkAndListenWhile: [count < 5].

Must be :

| count listener |
    count _ 0.
    listener _ TcpListener
        on: 8123
        handler: 
            [ :socket |
            count _ count + 1.
            Transcript show: socket getData.
            socket closeAndDestroy].
    listener forkAndListenWhile: [count < 5].

After looking for ComancheListener class in all images what have something
network related , I think maybe class was renamed and, yes, with new name
example works fine.

Edgar