Hi Richard,

I have copied the data sheet of Honewell micro, downloaded from <questlink.com>

I think with it your application can even work in hell.

Try it.

Good Luck

Babar/


HT83C51
High Temperature 83c51 Microcontroller
A product of Honeywell
Product Information
Data Sheet from Honeywell Server (89 kb PDF)
Price & Availability
Features
HTMOS Specified Over -55 to +225 degrees C
8-Bit CPU Optimized For 5V Control Applications
Four 8-Bit Bidirectional Parallel Ports
Three 16-Bit Timer/Counters with One Up/Down Timer/Counter and
Clock Out
Programmable Counter Array with:
Capture/Compare
Software Timer with Watchdog Capability
High Speed Output
Pulse Width Modulator
Interrupt Structure with Seven Sources and Four Priority Levels
Half Duplex Programmable Serial Port with:
Framing Error Detection
Automatic Address Recognition
64K External Program Memory Address Space
Description
The HT83C51 is a monolithic 8-Bit microcontroller that is pin equivalent to the
Intel 8XC51FC microcontroller. Fab-ricated with Honeywell's dielectrically
isolated high-tem-perature (HTMOS(tm)) process, it is designed specifically for
severe high-temperature applications such as down-hole oil well, aerospace,
turbine engine and industrial control.