1. 8751H was manufactured in HMOS technology, which cannot be at all compared with todays CMOS. For the 8751H from Intel a supply current of up to 250mA had to be expected, which corresponds to a heat dissipation of up to 5 V x 250mA = 1.25W!

2. Not all parts could run at 12MHz, some only at 8MHz.

3. Using the internal Pierce oscillator the same arrangement as today was used, means the crystal between XTAL1 and XTAL2 and a 30pF burden cap from each pin to ground.

But take care: When using an external oscillator, XTAL2 was used as input and XTAL1 had to be grounded!!

4. If the security bit in the 8751H is programmed, the device will not fetch code from external program memory!

5. The 8751H did not provide static operation, but needs a minimum clock frequency of 3.5MHz.

6. A fast power-on time is needed to prevent the device from locking-up.

Kai