System information

18. Load and test the debugger by typing

DDT

See Section 4 for operating procedures.

19. Before making further CBIOS modifications, practice using the editor (see Section 2),

and assembler (see Section 3). Recode and test the GETSYS, PUTSYS, and CBIOS

programs using ED, ASM, and DDT. Code and test a COPY program that does a

sector-to-sector copy from one disk to another to obtain back-up copies of the original

disk. Read the CP/M Licensing Agreement specifying legal responsibilities when copying

the CP/M system. Place the following copyright notice:

Digital Research

on each copy that is made with the COPY program.

20. Modify the CBIOS to include the extra functions for punches, readers, and sign-on

messages, and add the facilities for additional disk drives, if desired. These changes can

be made with the GETSYS and PUTSYS programs or by referring to the

regeneration process in Section 6.3.

You should now have a good copy of the customized CP/M system. Although the CBIOS

portion of CP/M belongs to the user, the modified version cannot be legally copied.

It should be noted that the system remains file-compatible with all other CP/M systems

(assuming media compatibility) which allows transfer of nonproprietary software between CP/M

users.

6.3 Second-level System Generation

Once the system is running, the next step is to configure CP/M for the desired memory size.

Usually, a memory image is first produced with the MOVCPM program (system relocator) and

then placed into a named disk file. The disk file can then be loaded, examined, patched, and

replaced using the debugger and the system generation program (refer to Section 1).

The CBIOS and BOOT are modified using ED and assembled using ASM, producing files called

CBIOS.HEX and BOOT.HEX, which contain the code for CBIOS and BOOT in Intel hex

format.

6.2 First-level Regeneration CP/M Operating System Manual

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