Peter,

Though I haven't used the Scenix, my understanding is that it is a high speed, somewhat optimized copy of the 16C54, which is not a chip I would recommend. I assume you are correct about the items you listed, but I don't know for sure, as I haven't used those parts. I would agree that the PIC does have some limitations which make coding more difficult.

I would recommend the 16C74, 16F877, and 18C452. All of these parts are pin and binary compatible, though with slight differences.

The 18C452 eliminates virtually every limitation you mentioned, with a deeper stack, prioritized and multiple vector interrupts, more instructions, linear address and data space, and higher speed(40MHz=10MIPS).

C programming does hide many of the pitfalls, but most of the compilers for the PICs are too buggy and inefficient for me. I stick with asm. A bit slower coding, but overall better resulting code. I must admit that most beginning PIC users suffer from bugs due to the bank and page architecture. Good coding practice eliminates those problems.

I have always found PICS quite easy to program, though the instruction sets on the 12 and 14 bit devices are somewhat limited. Microchip has a rather good web site to speed development.

As for code size, Microchip claims that the 16C7X typically achieves a 2:1 code compression and 4:1 speed improvement over other micros in its class. I know only that a 16C74 at 20 MHz will vastly outperform a 68HC11 based on my experience.

I meant not to start a debate, only to inform Rauf as to other options.

Regards,

Cory Spackman