Punched cards were, in the 1960's the universal symbol of computing, and even in the 1930's, they were a symbol of modernity. Today, cards are all but forgotten, surviving in a few applicatons such as turnpike toll receipts and automatic voting systems.
There were multiple mappings between the 12 holes of one card column and the character sets of various machines and keypunches.
The following software is available to encourage the development of museum quality emulators for antique computing and punched-card tabulating equipment:
The file format used by these programs is available, and I hope that emulators for historical computer architectures will support interchangable punched card I/O using this format and that a suite of emulated punched card data processing machines will be developed.
Paul Mattes has created an 026 keypunch emulator that supports this format and runs under X11 on Linux and some other Unix compatible systems! See x026 for a demo and an animated GIF of the user interface.
Punched cards were still commercially available from the California Tab Card Company of Whittier California as late as 2016, but their web site has since disappeared.
Cardamation was the last place to rent or buy punched-card data processing equipment. The owner, Robert G. Swartz died on Dec. 16, 2011, and it appears that Cardamation is no longer.
U.S. Card Corporation, formerly of Tiffin, Ohio, has closed its doors, as of early 2005, after a run of 32 years in the punched-card business.