>I still wonder why no PICs (or AVR's) have more than a few hundred bytes >RAM. True not many applications use more than a few dozen bytes. But I >have some in mind that need a couple Kbyte. Especially with dual serial >ports and decent processing speed, the opportunity is ripe for buffers, >protocol converters, error correctors, etc. Agreed. Suspect that its cost / die space required. Someone said the 17xx external rams needed to be very fast. This is expensive, in SRAM. SRAM also is somewhat expensive of die real estate. MikeS