[net.micro] Which Parallel I/O Chip?

rbc (01/11/83)

I am currently designing a micro processor board.
The problem is which parallel I/O chip will I use.
Currently the options are

	INTEL  8255A	3 8-bits ports
	or
	Synertek 6520A	2 8-bit ports with handshake signals

I have used both parts and am partial to the 6520A.
I have heard a few negative things about the 8255A:
   -	Single Bit I/O operations on ports A + B
	do not always work. 

   -	That writting the control register causes
	glitches on the outputs. (very bad)

Has anyone else heard this?  Any other gotchas?
Are there any other chips I should consider?

			Thanks.
			Robert Connaghan  -  Bell Labs; Holmdel, N.J.
			201-949-5649	(collect is OK)
			houxw!rbc