Thanks for your help. Once I knew I was compiling the Kernel correctly I soon tracked down where I had gone wrong. I had confused myself by already editing the /sys/lib/kbmap/uk map file. Although the '\' can be made to work that way, the code change cures all and means the original uk map works fin...

I have a non-responsive '\|' key. I have followed the instructions from https://groups.google.com/forum/#!topic/comp.os.plan9/ycok6NTCWCg and by editing /sys/lib/kbmap/uk I now have the '\' working. To get the shift+'\|' to give me '|' I have edited /sys/src/9/omap/kbd.c if(kbscan->esc1 && c != 0x58...