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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
;Extended operations
;
MAXEXT EQU 0Fh ;Maximum extended opcode.
;
ext_high:
scf ;Extended operations 128-255.
ret ;Entered with (inst+1) = opcode
;
ext_ops: ;0 1 2 3 4 5 6 7
defw d_save, d_restr, z_srl, z_sra, sfont, drawpic, picdata, erapic
defw smargin, u_save, u_restr,pruni, ckuni, fail, fail, fail
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
flags2: defb 0
;
save_magic: ;1...5...10..14 15 16
defb 'ZXZVM savefile',1Ah,2 ;(version 2)
save_hdr:
defs 16 ;Magic number
save_zpc:
defw 0,0 ;Program counter
save_mlen:
defw 0 ;DRAM length
save_slen:
defw 0 ;Z-stack length
save_rlen:
defw 0 ;Routine stack length
defs 102 ;Takes it up to 128 bytes
;<< v1.01
filever:
defb 0 ;Savefile version - 1 if the Z-stack has not been
;manipulated due to bug in v1.00, else 2
;>> v1.01
d_save: ld a,1 ;<< v0.02 >> Flag "Save as"
call ZXNAME
ex de,hl ;DE = filename parameter
call ilprint
defb 13,10,'$'
ld hl,abandoned ;<< v1.01 >>
ccf ;<< v0.02 >> Carry-reset return here means "cancel"
jp c,badsave ;<< v1.01 >> Don't RET, it will send the Z-machine
; into hyperspace!
ex de,hl ;Restore filename parameter
ld b,1 ;CREATE
call ZXOPEN ;CREATE savefile
jp nc,badsave
ld a,(v_argc) ;<< v1.00 Nasty SAVE bug in v3 games
cp 1 ; (and maybe others) - the base
jr nc,d_sav0 ; address was not being set to 0
ld hl,0 ; so save was from random address
ld (v_arg1),hl
d_sav0: ld a,(v_argc) ;>> v1.00
cp 2
jr nc,d_sav1
ld hl,0eh
ld e,0 ;Address of DRAM length
call ZXPKWI ;BC = DRAM length
ld (v_arg2),bc
d_sav1: ld hl,save_magic
ld de,save_hdr
ld bc,16
ldir ;Copy magic number into header
ld hl,(zpc)
ld (save_zpc),hl
ld hl,(zpc+2)
ld (save_zpc + 2),hl
ld hl,(zstop) ;Top of Z-stack
ld de,(zsp) ;Bottom of Z-stack
and a
sbc hl,de ;HL = Z-stack length
ld (save_slen),hl
ld hl,(rstop)
ld de,(rsp) ;Routine stack length
and a
sbc hl,de
ld (save_rlen),hl
ld hl,(v_arg2)
ld (save_mlen),hl
;
;Write out the header
;
ld hl,save_hdr
ld bc,128
call ZXWRIT
jp nc,badsave
;
;Write out the memory
;
ld bc,(save_mlen)
ld hl,(v_arg1) ;Base
call ZXWMEM ;Write z-machine memory
jr nc,badsave
;
call fixup_stack ;Write call stack.
ld bc,(save_slen)
ld hl,(zsp)
call ZXWRIT
call fixup_stack
jr nc,badsave ;Write routine stack
ld bc,(save_rlen)
ld hl,(rsp)
call ZXWRIT
;
ld b,1
call ZXCLSE
ld a,(zver) ;<< v0.04 Early versions branch if OK
cp 4
jp c,branch ;>> v0.04
scf
ld hl,1
jp ret_hl
;
ts_err:
ld a,(hl)
push hl
push af
and 7fh
ld l,a
ld h,0
ld a,1
call ZXZCHR
pop af
pop hl
inc hl
bit 7,a
jr z,ts_err
ld hl,0dh
ld a,1
call ZXZCHR
scf
ret
badsave:
call ts_err
ld b,1
call ZXCLSE
;
ld a,(zver) ;<< v0.04 Early versions branch not store
cp 4
jp c,nbranch ;>> v0.04
scf
ld hl,0
jp ret_hl
;
d_restr: ;"restore"
ld hl,10h
call peek64
ld (flags2),a
xor a ;<< v0.02 >> "Load" rather than "Save"
call ZXNAME
ex de,hl ;DE = "name" parameter
call ilprint
defb 13,10,'$'
ld hl,abandoned ;<< v1.01 >>
ccf ;<< v0.02 >> Carry reset here does not abort
jr c,badsave ;<< v1.01 >> nor send Z-machine into hyperspace
ld b,0 ;Open to read
ex de,hl ;HL = "name" parameter
;jr $
call ZXOPEN ;
jp nc,badsave
ld a,(v_argc) ;<< v1.00 v3 'save' bug fix
cp 1
jr nc,d_rstr0
ld hl,0 ;Start restoring at byte 0
ld (v_arg1),hl
d_rstr0: ;>> v1.00
ld a,(v_argc)
cp 2
jr nc,d_rstr1
ld hl,0eh
ld e,0 ;Address of DRAM length
call ZXPKWI ;BC = DRAM length
ld (v_arg2),bc
d_rstr1:
ld hl,save_hdr
ld bc,128
call ZXREAD
jp nc,badsave
ld hl,save_hdr
ld de,save_magic
ld b,15 ;<< v1.01 >> Can be v1 or v2
d_rstr2:
ld a,(de)
cp (hl)
inc hl
inc de
jp nz,d_rstr3
djnz d_rstr2
ld a,(hl) ;<< v1.01 Special check on savefile version
ld (filever),a
or a ;== 0
jp z,d_rstr3
cp 3 ;>= 3
jp nc,d_rstr3 ;Savefile versions 1 and 2 are acceptable
;>> v1.01
;
;Header recognised. Load Z-memory & stacks
;
ld a,(v_argc)
or a
jr nz,rstr_tab
ld bc,(save_mlen) ;Load memory
ld hl,0 ;Base
call ZXRMEM ;Read z-machine memory
jp nc,badsave
;
ld hl,(zstop)
ld de,(save_slen)
and a
sbc hl,de
ld (zsp),hl ;We have now passed the point of no return!
;Errors now result in game abort!
ld hl,(rstop)
ld de,(save_rlen)
and a
sbc hl,de
ld (rsp),hl
;<< v1.01 don't fixup stack for v1 savefile
push af
ld a,(filever)
cp 1
call nz,fixup_stack
pop af ;>> v1.01 Read call stack
ld bc,(save_slen)
ld hl,(zsp)
call ZXREAD
push af ;<< v1.01
ld a,(filever) ;Don't fixup stack for v1 savefile
cp 1
call nz,fixup_stack
pop af ;>> v1.01
ret nc
ld bc,(save_rlen)
ld hl,(rsp)
call ZXREAD
ret nc
call ZXCLSE
ld hl,(save_zpc) ;Returning from a successful restore.
ld (zpc),hl
ld hl,(save_zpc+2)
ld (zpc+2),hl
ld hl,2
ld a,(zver) ;<< v0.04 Branch if successful
cp 4
jp c,branch ;>> v0.04
scf
jp ret_hl
;
rstr_tab:
;
;Only load memory
;
ld hl,(v_arg1)
ld bc,(v_arg2)
call ZXRMEM
jp nc,badsave
ld hl,(v_arg2)
scf
jp ret_hl
;
d_rstr3:
ld hl,badfrm
jp badsave
;
fixup_stack:
push af ;For each entry in the Z-stack, replace its RSP
push bc ;entry with (RSPTOP - RSP). This operation is
push de ;self-inverse.
push hl ;Doing it like this means the stack in the savefile
push ix ;does not depend on the local ZXZVM's setting of
ld ix,(zsp) ;RSPTOP.
fixup_s1:
ld de,(zstop)
push ix
pop bc
call cpdebc
jr z,fixend
ld e,(ix+36)
ld d,(ix+37) ;DE = associated RSP
ld hl,(rstop)
and a
sbc hl,de ;HL = RSP offset
ld (ix+36),l ;<< v1.01 - write back the RESULT, not
ld (ix+37),h ;>> v1.01 the parameter!
ld bc,38
add ix,bc
jr fixup_s1
;
fixend: pop ix
jp popd
;
badfrm: defb 'Not a ZXZVM savefile'
defb 0AEh ;'.'+80h
;
abandoned:
defb 'Operation abandoned'
defb 0AEh ;'.'+80h
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
;ZXZVM does not support Undo in this incarnation. We can't guarantee
;enough memory in the target computer to hold the RAMsaved undo image.
;
;Possibly in the future this could be implemented (some PCWs have enough
;memory) but the speed hit might be too much for a 3.5MHz Z80 to take.
;
u_save: ld hl,0ffffh ;RAMsave failed
scf
jp ret_hl
;
u_restr:
ld hl,0 ;RAM restore failed
scf
jp ret_hl
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
z_srl: ld hl,(v_arg1) ;logical shift
ld bc,(v_arg2)
bit 7,b
jr nz,z_srlr
z_srll: add hl,hl
dec c
jr nz,z_srll
z_srlm: scf
jp ret_hl
;
z_srlr: res 7,h
call absbc
z_srlt: srl h
rr l
dec c
jr nz,z_srlt
jr z_srlm
;
;Arithmetic shift
;
z_sra: ld hl,(v_arg1)
ld bc,(v_arg2)
bit 7,b
jr z,z_srll
call absbc
z_srar: srl h
rr l
bit 6,h
jr nz,z_srat
set 7,h
z_srat: dec c
jr nz,z_srar
scf
jp ret_hl
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
;set_font
;
sfont: call flush_buf ;<< v1.02 >> Flush buffers before
ld a,(v_arg1) ;changing fonts
call ZXSFNT
ld l,a
ld h,0
scf
jp ret_hl
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
;v6 routines (no-ops)
;
erapic:
drawpic:
smargin:
scf
ret
picdata:
jp nbranch
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
;Unicode routines
;
pruni: ld hl,(v_arg1)
ld a,h
or a
scf
ret nz ;Only allow ASCII characters to print
jp prchar
;
ckuni: ld de,(v_arg1)
ld hl,0
ld a,d
or a
jr nz,ckunie
set 0,l
ld a,e
cp 128
jr nc,ckunie
set 1,l
ckunie: scf
jp ret_hl