Hi Seema,
What microprocessor/microcontroller are you using?

Well, as far as your question, I don't think there is such kind of a chip as 8279.

If the processor is MCS-51 family, then you will find tons of application notes for keyboard/display functions. These functions can be performed by the MCS-51 chip itself, you might optimize the design later on.

If your requirement for an 8279 kind of device is a must, then you can probably have a slave processor (MCS-51 family, 20/40 pin devices, low cost, or some other small processors such as microchip, etc., or even FPGA, CPLDs,) and have the main processor communicate with this slave processor. You will find lots of application notes and threads on this forum for communicating between 2 processors.

Using a slave processor is more economical compared to using 8279, because, the interface pins required is less, so pcb size is reduced, and the cost of 8279 is at present sky high compared to low cost CPUs. In Mumbai,India, the cost of 8279 is approx. Rs.300/-, whereas the a low cost processor AT89C51 will cost Rs.55/-.

With best regards from,

Mr. Kiran V. Sutar.