7437 Quad Two input NAND in Pakistan

These full adders perform the addition of two 4-bit binary
numbers. The sum (R) outputs are provided for each bit and
the resultant carry (C4) is obtained from the fourth bit.
These adders feature a full internal look ahead across all four
bits. This provides the system designer with a partial lookahead
performance at the economy and reduced package
count of a ripple-carry implementation.

74LS109 IC in Pakistan

74LS Series ICs are High-Speed Logic gates, ideally a little faster than the 74HC series but more power consumption is required. They are implemented with a Low-Power Schottky diode technology to achieve high switching speed. 74LS148 is one of the 74LS series IC. 74LS148 ICs contain an 8 to 3-Bit priority encoder that converts 8 Data Lines to 3-Line binary. Cascading circuitry (enable input EI and enable output EO) has been provided to allow octal expansion without the need for external circuitry.