The i386-Engine-P is based on the i386-Engine design, and offers an on-board 5-volt regulator and two RS-232 drivers, high-speed ADC, and more on-board memory in addition to standard IE features. The third optional UART SCC2691 can be either RS-232 (default) or RS-485, to be specified when ordering. The i386-Engine-P does not require the VE232.

In addition to the 512 KB 8-bit SRAM and 512 KB 8-bit ROM/Flash, the IE-P supports up to 1 MB 16-bit SRAM and 1 MB 16-bit Flash. A 16-bit ADC (LTC1605, 100 kHz, +-10V) or a 12-bit ADC (LTC1415, 1.2 MHz, 0-5V) can be installed. Eight additional TTL outputs are designed for operating an external analog multiplexer. The switching power regulator is useful for lowering power consumption.