ST Microelectronics ST90T40C6

data_sheet (PDF) device PLCC-68 package

programming best with SMS or DATAIO programmer Sprint Expert, Sprint Optima, Sprint Dual

applications

st9 µC family

ST9040 1st Edition Manual

st9 family programming manual

st9 debugger

ST9 FAMILY 8/16 BIT DATA BOOK 1st Edition July 1991

https://www.rsp-italy.it/Electronics/Databooks/SGS/_contents/SGS%20ST9040%20Family%208,16%20bit%20MCU%20databook%201993.pdf April 1993 edition