Hi antedeluvian
Thanks for the help. Yes, it is a 0.3" wide 28-pin DIP. The pinouts don't match any chip from Atmel, Microchip, Freescale, Philips or ST, and from the info you provided it seems to be a Cypress PSoC chip.
Hi polymath
Your suggestion about the 28-pin module board is a good idea, though my experience with PICs has not been very encouraging. The PIC16 instruction set has very limited capabilities as compared to 8051 or 68HC11. You have to use 3 or more instructions for many tasks which are possible with single instruction in other MCUs plus you have to keep switching banks to access various SFRs.
I fail to understand the reason about PIC's popularity when such other good architectures are available.