Jak znaleźć brakujący znak w kodzie ASCII dla Osborne 1?

Osborne 1 Specification napisał:

The boot program loader and significant parts of the BIOS were stored in a 4 kilobyte EPROM, which was bank-switched. A second EPROM was used as a fixed character generator, providing upper and lower case ASCII characters and graphic symbols; the character generator was not accessible to the CPU. The eighth bit of an ASCII character was used to select underlined characters.