in some parts (a subroutine could not call another subroutine), with 2 or 3 levels available on others. Each instruction took between 10 and 15 microseconds to execute on the NMOS and PMOS parts, but some CMOS parts could be run as fast as 6 microseconds. The internal oscillator gave an effective clock speed of around 0.3 megahertz. The TMS1000 parts were packaged in through-hole dual in-line packages with 28 or 40 pins, but some models for prototyping were in 64-pin packages. All versions had a temperature range of 0 to 70 degrees C. Since these were intended as single-chip embedded systems, no special support chips UARTs, etc. were specifically made in the TMS 1000 family. References Further reading TMS1000