IBM introduced the 80-column rectangular hole punched card in 1928. Pre-1928 machine models that continued in production with the new 80-column card format had the same model number as before. Machines manufactured prior to 1928 were, in some cases, retrofitted with 80-column card readers and/or punches thus there existed machines with pre-1928 dates of manufacture that contain 1928 technology.
IBM introduced the 80-column rectangular hole punched card in 1928. Pre-1928 machine models that continued in production with the new 80-column card format had the same model number as before. Machines manufactured prior to 1928 were in some cases, retrofitted with 80-column card readers and/or punches thus there existe,d machines with pre-1928 dates of manufacture that contain 1928 technology.