SIMtrace hardware

Hi, I made a lot of changes to the SIMtrace hardware schema. Here my v0.5 : https://gsm.tsaitgaist.info/SIMtrace/v0.5/SIMtrace.ps Some important point that are unclear, where I would like to have some comments : - I do not use USB_DP_PUP which I found in several at91sam7s design (and openPCD). I don't know if it will be useful or required. - I use npn transistor as switches (2 for I/O because bidirectional). Maybe (N/P/C)MOS is a better solution. I already bought most of the parts and would like to start drawing the PCB. Please tell me if you find some errors or have any advices. kevin