.comment ~

 Library:  Z34CMN.LIB
 Author:   Joe Wright
 Date:     23 March 1988

 Modern assemblers provide for the use of up to twelve named common
 blocks.  The actual addresses of these blocks need not be known at
 the time of assembly, but are supplied later by the linker or loader.
 NZ-COM will allow the use of seven of these twelve blocks.

 This library is to be included in the assembly of the segments in
 place of Z3BASE.LIB.  Note that the seven blocks declared here have
 only equates and no code or data.  Only one common (_ID_) is allowed
 to contain data.  If it is used, it is declared separately in the
 source of the particular segment.  The _ID_ common data is read but
 otherwise ignored by NZCOM.


           Assembly Notes for ZCPR3 modules and NZ-COM
                          by Joe Wright
                           26 March 88

NZ-COM uses MicroSoft or SLR .REL modules to build the  Z-System.  
The  modules  are written so as to 'stand alone'.  There  are  no 
direct  inter-module  references.  Rather the modules  treat  the 
ZCPR3   environment  and  obtain  required  data  and   addresses 
indirectly.    The  environment  descriptor  now   includes   the 
addresses of the CBIOS, CCP, DOS and BIOs. as follows:

Z3ENV+
0000      DB   0C3H      ; As always..
0001      DW   CBIOS     ; For NZ-COM, this is CBIOS+6

0008      DB   80H       ; Env Type.  bit 7 means 'Extended'

0034      DW   DRVEC     ; Valid drive vector allows 'holes'

003F      DW   CCP       ; Address of ZCPR3
0041      DB   CCPS      ; Its size in records (normally 16)
0042      DW   DOS       ; Address of the disk operating system
0044      DB   DOSS      ; Its size (normally 28 records)
0045      DW   BIO       ; Address of NZBIO (no size)


                        Notes on Assembly

NZ-COM  uses Named COMMON blocks to provide direct references  to 
the  'minor'  segments,  Z3ENV,  SHSTK,  Z3MSG,  etc.   The  file 
Z34CMN.LIB replaces Z3BASE.LIB for all assemblies.  All files are 
assembled  to .REL (MicroSoft or SLR).  NZCOM.COM  also  requires 
the modules to be specifically named.  This is accomplished  with 
the NAME pseudo-op as follows:

     NAME      ('CCP')        ; Declare module name
     MACLIB    Z34CMN.LIB     ; In place of Z3BASE.LIB
     MACLIB    Z34HDR.LIB     ; Configuration header

Assembly conditionals are treated a little differently.   Because 
module  addresses  are no longer assigned at  assembly  time,  we 
cannot  use the address as an existence test, rather we  use  the 
module 'size' indicator.  The old IF FCP NE 0 test is changed  to 
IF  FCPS NE 0.  FCPS is defined in Z34CMN.LIB as an absolute  YES 
or NO.  Of course, the same holds true for RCP, IOP and Z3NDIR.

Because  they  are defined in Z34CMN.LIB,  direct  references  to 
Z3ENV,  SHSTK,  Z3MSG,  Z3CL and the like  are  still  permitted.  
Addresses  and  sizes of the dynamic segments  must  be  obtained 
indirectly  from Z3ENV.  Instead of LD HL,FCP we use LD  HL,(FCP) 
which is defined in Z34CMN.LIB as Z3ENV+18.

                        End of NZASM.NOT


~


; As a replacement for Z3BASE.LIB, some usual equates.

base	equ	0		; Base Page

false	equ	0
true	equ	not false

no	equ	false
yes	equ	true

off	equ	false
on	equ	true

; Named COMMON declarations start here.  For compatibility, these
; are the same names used by Bridger Mitchell's JetLDR.

	common	/_ENV_/
z3env:				; Z3 Environment descriptor
z3envs	equ	yes		; There is one

expath	equ	z3env+9		; Address of External Path
expaths	equ	10		; Maximum 10 elements for MPATH

rcp	equ	z3env+12	; Address of RCP
rcps	equ	yes		; Used as existence test, not size

fcp	equ	z3env+18	; Address of FCB
fcps	equ	yes		; Used as existence test, not size

z3ndir	equ	z3env+21	; Address of NDR
z3ndirs	equ	yes		; Used as existence test, not size

z3quiet	equ	z3env+28h	; Quiet flag ( 1= quiet )

z3whl	equ	z3env+29h	; Wheel byte address
z3whls	equ	yes		; There is a wheel

drvec	equ	z3env+52	; Valid drive vector

ccp	equ	z3env+63	; CCP entry
ccps	equ	z3env+65	; Size

dos	equ	z3env+66	; DOS entry (+6)
doss	equ	z3env+68	; Size

bio	equ	z3env+69	; BIO entry

	common	/_SSTK_/
shstk:				; Top of Shell stack
shstks	equ	yes		; There is a shell stack

	common	/_MSG_/
z3msg:				; Message buffer
z3msgs	equ	yes		; There is one

	common	/_FCB_/
extfcb:				; External file control block
extfcbs	equ	yes		; There is one

	common	/_MCL_/
z3cl:				; Multiple command line
z3cls	equ	yes		; There is one

	common	/_XSTK_/
extstk:				; External stack
extstks	equ	yes		; There is one

	common	/_BIOS_/
bios:

	cseg			; Select Code Segment

; End of Z34CMN.LIB

fcp	equ	z3env+18	; Address of FCB
fcps	equ	yes		; Used as existence test, not size

z3n