Hello Friend's!! 27 Series of PROM & EPROM today's young generation are mostly not aware off, the most widely used ROM from 1980's till date specially the industrial sector, My this Standalone ROM copier circuit I developed in the year 1995, many of my student's made it & learned writing data in ROM using a breadboard. Today the ROM has changed from parallel data ROM to Serial ROM with 24 and 25 series. Just wanted to share my old memories. Be blessed and enjoy developing circuits. Love You All. We are electronics circuit designers since last 3 decades and have touched almost all domains in electronics and mechatronics. Visit www.compudrivesystem.com.