TULIP4041 Startup Question

[MeindertKuipers]

Good to hear that things seem to be working.

If you see the TRANSMIT ERR please check with the tracer if there is any activity on FI (if you have the extra buffer installed). For tracing FI also JP2 must be closed! I have seen this sometimes after installing new firmware. Best is to disconnect from the HP41 and USB and restart everything. I will try to reproduce later today since I am building a new TULIP myself.
As an extra check (but unlikely) you could verify the physical connections of the FI signal all the way from the HP41 connector to the input buffer.