I received my 28X2's today and quickly got to testing.
To check I have everything wired correctly I used this small test program
main:
for b0=32 to 255
sertxd (b0," ",#b0,cr,lf)
; serout b.7,n2400, (b0," ",#b0,cr,lf)
pause 150
next b0
goto main
Picaxe runs fine.
However the simulation...