Here're some ways to change a TTY's resolution in Linux:
a. Try to use the command fbset. It can be used to change the framebuffer device settings, which related to the display of TTY.
eg. fbset 1280x1024-60
For more information about the usage of fbset and its relation with tty, check man page and google.
This change is temporary and will be reset after reboot.
b. If you are using grub and grub2, you can make it by changing the grub settings. For more information, check this: https://help.ubuntu.com/community/ChangeTTYResolution
c. If you only want to change the font size under TTY instead of the resolution, check this: http://askubuntu.com/questions/548522/resize-font-on-boot-message-screen-and-console