CBBSLINK.DOC
                           07/12/81
     DOCUMENTATION ON ASSEMBLING CBBS WITH "LINKASM.COM"


     Due to the size of the CBBS program source, it has been¨
broken up into several smaller .ASM files, which MUST be¨
assembled with LINKASM.COM.
     At first, I would assemble CBBS by PIPping all the files¨
together, but this took excessive time and requires quite a bit¨
of disk space.  I then wrote a program which combines the¨
files, eliminating all comments.  This, eventually, also became¨
unwieldy.
     The final solution was to come up with an assembler which¨
could handle multiple source files so the files need not¨
physically be copied before assembling.
     The only alternatives readily commercially available are¨
the Microsoft ASM-80 assembler or the Digital Research RMAC,¨
which require separate assemblies, and a linkage editor to¨
combine object modules.  This would not be a bad solution, but¨
has the following drawbacks:

1.   CBBS users would have to buy one of the assemblers.

2.   When debugging, the listing would not have the proper¨
assembly addresses, and lots of hex calculating would have to¨
be done.

3.   Worst of all, no .SYM file would be generated.  This would¨
significantly impede debugging using Digital Researches SID¨
(Symbolic Instruction Debugger).  I would not attempt to modify¨
or maintain CBBS without SID.

     I rewrote the CP/M assembler version 1.0, to handle a new¨
pseudo-op code, LINK.  I moved the I/O buffers out of the¨
middle of the code, to the end where they don't have to be¨
loaded with the .COM file.  I also increased the buffer sizes,¨
to: 

	1000H	.ASM BUFFER SIZE
	800H	.HEX BUFFER SIZE (earlier versions were 400H)
	400H	.PRN BUFFER SIZE


     Extra code (JMP tables for hand-link editing, space¨
padding for subroutine expansion and patches, etc) were¨
removed.  I incorporated a patch to handle lower case¨
characters, and corrected it so it handles DB statements which¨
include double quotes like:

	DB	'I don''t know what you mean'

     Each file has a LINK pseudo op as the last instruction in¨
the file.  CBBS.ASM is the first one, and results in linking to¨
all the rest.  To run the assembly, execute:

                 LINKASM CBBS.SHP [symdisk:]

Where S is the source disk, H the hex disk, and P the prn disk.
     This is the same as the normal CP/M assembler, i.e. Z may¨
be used for either the .hex or .prn disk, and X may be used for¨
the .prn disk, to direct it's output to the console. Added is¨
the "symdisk:" (e.g. A: or B: with no filename)  which¨
specifies a symbol table for use under SID will be  written as¨
CBBS.SYM.  It is partially sorted (all As then all  Bs, etc).
     For example, an assembly of CBBS on a 2 disk system, with¨
LINKASM on A:, and CBBS .ASM files on B:, with the .HEX and¨
.SYM files written to B:, and the .PRN  file thrown away, would¨
be:

                     LINKASM CBBS.BBZ B:


     If for some reason you do not like the idea of LINKASM,¨
i.e. perhaps you insist on having Macros in it, then edit out ¨
the  LINK pseudo ops from each file, and PIP the following¨
files together, in order, end-to-end.  ...But the result would¨
be a relatively unwieldy .ASM file of perhaps  128K or more,¨
and over 7000 lines.  Without stripping lots of comments, it¨
couldn't even be edited on 1 single density disk.
     The utility program "FAST" has been included on this disk. ¨
If you have a moderate amount of memory, it allows options such¨
as full track read and/or write buffering, and  directory¨
buffering, on 1 or more disks.
     A brief overview of FAST.COM:  Just say FAST before your¨
other command, such as:

                FAST [BY] LINKASM CBBS.BBZ B:

<<CP/M 1.4 only>> 

     This says you want B disk buffering, with the Y saying you¨
want all types (1 track read buffer, 1 track write buffer, and¨
a directory buffer (seek buffer)).  See FAST.DOC for details. ¨
This excellent speeder-upper was written by Bob Van Valzah. See¨
FAST.DOC for details.
                ASSEMBLY ORDER FOR CBBS FILES


		CBBS	.ASM
		CBBSFUNC.ASM
		CBBSBYE	.ASM
		CBBSSUMM.ASM
		CBBSENT1.ASM
		CBBSENT2.ASM
		CBBSRTRV.ASM
		CBBSOPER.ASM
		CBBSKILL.ASM
		CBBSDISK.ASM
		     !
COMPUTIME CLOCK:  IF CLOCKC---> CBBSCLKC.ASM----+
		     !				!
SCITRONICS CLOCK: IF CLOCKS---> CBBSCLKS.ASM	!
		     !		    !		!
		     !<-------------+<----------+
		     V
		CBBSSUB1.ASM
		CBBSSUB2.ASM
		CBBSSUB3.ASM
		     !
		  IF PMMI------>CBBSPMMI.ASM----+
		     !				!
		  IF HAYES----->CBBSHAYS.ASM--->!
		     !				!
		  IF IDS------->CBBSIDS.ASM---->!
		     !				!
		  IF SERMODM--->CBBSMODM.ASM--->!
						!
		     +<-------------------------+
		     !
		     V
		CBBSWORK.ASM