mirror of
https://github.com/wwarthen/RomWBW.git
synced 2026-02-06 14:11:48 -06:00
80 lines
2.1 KiB
Z80 Assembly
80 lines
2.1 KiB
Z80 Assembly
|
||
;+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
|
||
; S E T Z 3
|
||
; for ZPM3
|
||
; by Simeon Cran
|
||
; 30/3/92
|
||
;
|
||
; This program automatically sets the system environment address in the ZPM3
|
||
; SCB for Z3PLUS users. Certain advanced ZCPR facilities such as wheel
|
||
; protection of files will then be activated.
|
||
;
|
||
; Z3PLUS users should run SETZ3.COM once when they start up Z3PLUS and again
|
||
; when returning to regular (non-Z-System) operation. When run after Z3PLUS
|
||
; is started, the SCB environment address word is set with the ZCPR environment
|
||
; address. When run after returning to regular operation, the SCB environment
|
||
; address word is cleared to 0000h.
|
||
;
|
||
;+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
|
||
|
||
;===============================================================================
|
||
|
||
BDOS equ 5
|
||
deffcb equ 5ch
|
||
SCBfunc equ 31h ; Get/Set SCB function number
|
||
SCBoff equ 3bh ; Offset in SCB to get SCB base page
|
||
Z3ENVoff equ 83h ; Offset in SCB base page of the ZCPR system
|
||
; environment pointer.
|
||
|
||
jp start ; Jump over general data
|
||
db 'Z3ENV'
|
||
db 1
|
||
Z3ENV: dw 0
|
||
dw 0
|
||
HELPmsg:
|
||
db ' SYNTAX:'
|
||
db 10,13
|
||
db ' SETZ3'
|
||
db 10,13
|
||
db ' Sets the ZCPR environment address in the SCB,'
|
||
db 10,13
|
||
db ' or else clears it if not running ZCPR.'
|
||
db 10,13
|
||
db ' SETZ3 // Displays this brief help message'
|
||
db '$'
|
||
|
||
HELP: ld de,HELPmsg
|
||
MSGexit:
|
||
ld c,9
|
||
call bdos
|
||
rst 0
|
||
|
||
start: ; Get the address of the SCB environment address pointer.
|
||
ld de,(Z3ENV)
|
||
ld a,d
|
||
or e ; Has it been set by Z3PLUS?
|
||
jr nz,Zinstall ; Jump if it has
|
||
ex de,hl
|
||
ld a,d
|
||
or e ; Was it in HL instead?
|
||
jr nz,Zinstall
|
||
Zinstall: ; DE holds 0 if uninstalling, otherwise the address of the
|
||
; ZCPR evironment descriptor.
|
||
push de
|
||
ld c,SCBfunc
|
||
ld de,SCBPB
|
||
call bdos ; Get base page of SCB
|
||
ld h,a
|
||
ld l,Z3ENVoff ; HL is now the address of the word
|
||
pop de
|
||
ld (hl),e
|
||
inc hl
|
||
ld (hl),d ; Set it appropriately
|
||
rst 0 ; And exit.
|
||
|
||
|
||
SCBPB: ; System control block function parameter block.
|
||
db 03bh
|
||
db 0 ; Get operation
|
||
|
||
|