hi
thanks for ur observations Oleg and Kai.
i went to market and got some LEDs. documentation of the part number was not available. on testing, the average forward voltage was 1.5v. i discovered that most with their datasheets online can handle up to 50mA for short periods. so, i will make current limit be say 35mA.(the resistor as in Olegs diagramwill thus be 100 ohm)

the other resistors at the base of the PNP xtor are 2.2k and 10k (hope that works)

the PNP xtor are A733.

i got 74LS595 for the rows as well as BC339 xtors as buffers. i couldn't find 74LS datasheet but that of 74HC i saw indicated it can not handle up to that current. (i thought u said it can replace both the LS164 and the buffer?

the MCUs available are P8051AH, P8052AH, and 27xx roms
i will go back again if ay with a flash memory is available (so i can erase and reprograme ti at any time especially if i discover a mistake after burning.

PLs recommend some low priced but good ones as well as how to go about building the programmer myself, the (free) softwares i will require to do the programming, etc.

Regards,
Ehigie.