Analysis of information sources in references of the Wikipedia article "Commodore 128" in English language version.
A numeric keypad (the number keys clustered together as they are on a calculator) is useful for anyone entering large amounts of numeric data, but this feature was lacking on the Commodore 64. Since many Commodore 64 owners spent hours entering machine language programs in the form of long lists of numbers, this feature was often asked for.
C-128 CP/M uses both the Z80 and 8502 processors. The Z80 executes most of the CP/M BIOS functions.
C128 CP/M programmers who want to add or change operating system features should try to make changes to the BIOS. For one thing, BIOS source code is available, but not available for the BDOS or CCP.