Final answer:
Programs like 'mail' and 'remote file access' allowed users of a big central computer to send messages and share files with other users on the same computer.
Step-by-step explanation:
One program that allowed users of a big central computer to send messages to the personal folders of other users sharing the same computer was called 'mail'. This program provided a way for users to send and receive electronic messages within the computer system. Another program that facilitated this communication was 'remote file access'. This program allowed users to access and transfer files from one user's personal folder to another user's folder.
For instance, if User A wanted to send a message to User B's personal folder, they could use the 'mail' program to compose and send the message. Similarly, if User A wanted to share a file with User B, they could use the 'remote file access' program to transfer the file to User B's folder. These programs enabled efficient communication and file sharing among users of a big central computer.
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