Multiloader from Stellar Contour. Latest optimization.
ZXNet echo conference «code.zx»
Hi, All!
In general, I’m releasing the source code of the loader from our Stellar Contour demo to the masses. In it,
Unlike the loader in Tryptomine Dream there are 3 degrees of optimization, not just one.
In general, read the source, everything is explained there clearly.
The source was created in ZXASM 3.10, so perhaps something will not work in
other asmakhs, but I tried to use the most standard assembler
features.
Actually, the work with TRDOS itself is at the very end of the multiloader, that’s all
the rest is the logic of the work. ;)))
═══════════════════ LOADER .t ══════════════════
;(C) Vivid & Tigrr from Brainwave
;AFTER ASSEMBLY YOU CAN RUN
;EVERYTHING SHOULD WORK NORMALLY
L3D13 EQU 0
L3D2F EQU 1
;DB TYPE(L3D13,L3D2F),LAG_UP,LAG_NEXT,PORTION
DRIVER MACRO:DB =1,=2,=3,=4:ENDM
popytki equ 3;NUMBER OF READING ATTEMPTS
;ONE SECTOR, AFTER WHICH
;THE SECTORS WITH WILL BE READ
;NEXT TRACKS
;3 - JUST RIGHT.
INTTAB equ #be00
INTSP equ INTTAB.h+1*257
;WARNING, A LOADER IS REQUIRED
;FOR WORK THE PLATE IS SIZE 1 KILOBYTE
sectb equ INTTAB-#100 ;PLATE 1[256]
ADRTB EQU sectb-#300 ;PLATE 2[768]
;BEFORE AND AFTER LAUNCHING THE LOADER
;CAN BE USED AREA AREA
;PLATES FOR YOUR OWN PURPOSE
org #6000
JP BEGIN
BEGIN
;EXAMPLE OF USING THE LOADER:
LD IY,#5C3A
;SET FOR DISK DRIVE A (POSSIBLE
;THROW OUT)
LD A,0
LD C,1CALL #3D13
LD C,#18
CALL #3D13
;INSTALLED THE LOADER
;DATA FOR THIS MUST BE AVAILABLE
;AT ADDRESS DRIVEA
CALL INSTALL
;TURN ON INTS
D.I.
LD HL,INTTAB
LD A,H
LD I,A
INC A
SETINT1 LD (HL),A
INC L
JR NZ,SETINT1
INC H
LD(HL),A
IM 2
LD L,H
;DURING LOADER OPERATION
;THE HANDLER MUST BE
;PROCEDURE inter
LD (HL),#C3
INC HL
LD (HL),inter
INC HL
LD (HL),inter/256
EI
;LOAD 27 SECTORS FOR EXAMPLE
;From TRACK 1 AND SECTOR 0
LD HL,#4000;LOAD ADDRESS
LD DE,#0100;ROAD AND SECTOR
;(CURRENT TRACK AND SECTOR ARE STORED
;IN VARIABLE #5CF4). LOADER
;DURING ITS OPERATION, IT UPDATES
;IT'S AS IT SHOULD BE.
LD B,27
CALL IM2LOAD
;NOW YOU CAN TRY TO LOAD
;SEVERAL SERIOUS FILES AT A TIME
; ADR PAGE LENGTH
;1.#4000 #10 #10
;2.#C000 #17 #18
;3.#8000 #10 #08
LD HL,LOAD1DAT;WHAT AND WHERE WE SHIP
LD DE,(#5CF4);HAG. DOR. AND SEC.
CALL LOADGRP;LOADING GROUP
;FILES
;TURN OFF THE INFORMATION
IM 1
;LET'S EXIT
RET
;MAKE A MINI SETUP THAT
;WOULD JUST PUT IN THE NECESSARY BYTES
;AT ADDRESS DRIVEA
; PAY SPECIAL ATTENTION TO THE PARAMETER
;LAG_UPPER, BECAUSE IT IS ENTERED THERE;VALUE EQUAL:
;(16-L)�F, WHERE L IS THAT BAYDA,
;WHICH WAS DISPLAYED IN RDS IN THE FIELD
;LAG TRACK, I.E.:
;
;RDS LAG_UPPER
;0 #00
;1 #0F
;2 #0E
;..
;#0F #01
;
;
;WHY IS THIS?
;BECAUSE (FOR LAG1):
;
;TRK0: 0123456789ABCDEF
;TRK1: F0123456789ABCDE
;
;HERE THE NUMBER IS ENTERED IN LAG_UPPER
;SECTOR TRK1 WHICH IS _ABOVE_
;0 SECTOR TRK0, I.E. #0F
;
;INCORRECTLY SET LAG_UPPER MAY
;BREAKINGLY SLOCK THE LOADER
;
;
; IN THE LAG_NEXT FIELD IN PRINCIPLE IT IS POSSIBLE
;PUT 0, IT DOESN'T GET MUCH SPEED
;IT DEPENDS HIGHLY.
;
;
;BENEFITS OF UPLOADING A GROUP OF FILES IN
;THAT HE READS THEM LIKE ONE BIG
;FILE, BUT EACH SECTOR OF EACH FILE
;READS IN HIS PLACE. THE WHOLE POINT IS:
;THAT THE LOADER USES SEVERAL LEVELS
;OPTIMIZATIONS:
;
;1. OPTIMIZATION AT SECTOR LEVEL
;I.E. IF DURING LOADING A SECTOR
;THE ERROR OCCURRED OR AN INTERRUPTION OCCURRED,
;LOADER WILL TRY TO READ THE NEAREST
;(IN THE MEANING OF DISK ROTATION TIME)
;BEHIND THERE IS ANOTHER UNREAD SECTOR WITH THE CURRENT-
;ON THE UPPER SIDE OR FROM THE TOP (IF THERE IS THERE)
;THERE ARE UNREAD SECTORS).
;2. OPTIMIZATION AT TRACK LEVEL
;IF ANY OF THE SECTORS IS NOT
;READ FOR popytki ATTEMPT, THEN
;UNREAD SECTORS WILL BE READ
;FROM THE NEXT (PREVIOUS) TRACKS.
;THOSE. PERIODICAL
;MOVE THE HEAD BACK AND HERE IN
;WITHOUT ONE FILE. GIVEN
;OPTIMIZATION DOES NOT HAVE ANY EFFECT
;IFFECTS ON NORMAL DISK DRIVES,;SINCE 3 ATTEMPTS HAPPEN
;READING ALL 32 SECTORS AT CURRENT.
;THE TRACK, BUT ON THE DISK DRIVES, SPEED
;ROTATIONS OF WHICH ARE "SYNCHRONIC" WITH FREQUENCY
;FRAME (INTERRUPTION COMES CONSTANTLY
;DURING THE SAME SECTOR)
;ALLOWS YOU TO INCREASE READING SPEED
;2-3 TIMES COMPARED WITH NO
;THE OPTIMIZATION.
; THIS OPTIMIZATION DOES NOT PLAY ANYTHING
;ROLES IF THE WHOLE FILE FITS
;HA ON THE SAME PHYSICAL TRACK.
;
;3. OPTIMIZATION AT THE FILE LEVEL.
;WORKS ONLY WHEN READING A GROUP
;CONTRACTIVE
;FILES. ESPECIALLY NOTICEABLE BENEFITS WHEN
;READING SEVERAL SMALL FILES
;SECTORS OF 10-15 EACH IN A CONTRACT,
; HERE BY "FILE" MEANS
;JUST A BLOCK OF SEVERAL (#01-#E0)
;CONTINUOUS SECTORS.
;LIMITATION: TOTAL FILE VOLUME
;IN ONE GROUP MUST NOT EXCEED
;#E0 (240) SECTORS (56 KILOBYTES).
;IF YOU NEED TO READ IT
;MORE #E0 SECTORS, I RECOMMEND
;CREATE 2 APPROXIMATELY THE SAME GROUPS
;FILES, EACH OF WHICH IS NOT LONGER
;#E0 SECTORS
;FOR EXAMPLE, YOU MUST READ THE FOLLOWING
;CONTINUOUS FILES:
; BANK ADDRESS LENGTH(SECTORS)
;1. #8000 #10 #80
;2. #C000 #11 #40
;3. #C000 #13 #40
;4. #C000 #14 #40
;5. #C000 #16 #40
;6. #C000 #17 #40
;--------------------
; #1C0 = 2*#E0
;THEN IT’S SMART TO MAKE 2 GROUPS:
;
;GROUP1 DB #80,#10:DW #8000
; DB #40,#11:DW #C000; DB #20,#13:DW #C000 ;HALF
; ;3TH FILE
; DB 0 ;I.E. IN TOTAL #E0 SECTORS
;
;GROUP2 DB #20,#13:DW #E000;2ND HALF
; ;3TH FILE
; DB #40,#14:DW #C000
; DB #40,#16:DW #C000
; DB #40,#17:DW #C000
; DB 0
;AND LOAD THEM LIKE THIS:
; LD DE, TRACK AND SECTOR; POSSIBLE
; ;TAKE FROM (#5CF4)
; LD HL,GROUP1
; CALL LOADGRP
; LD DE,(#5CF4)
; LD HL,GROUP2
; CALL LOADGRP
;
; EVERYTHING IS AS SIMPLE AS 2 KOPENKS
;
;SO, YOU NEED ONLY 3 ENTRY POINTS
;1. INSTALL - INITIALIZING THE LOADER
; CALLED ONLY ONCE
; OR WHEN CHANGING THE DISK DRIVE
; (THE DISK DRIVE NUMBER IS TAKEN FROM
; TRDOS SYSTEM VARIABLES)
; AT DRIVEA ADDRESS MUST
; INFORMATION ABOUT 4 IS AVAILABLE
; DISK DRIVES (3D13 OR 3D2F,
; WHAT LAG_UP, LAG_NEXT AND SOFTWARE
; HOW MANY SECTORS SHOULD BE COUNTED AS
; ONCE IF LOADING VIA
; 3D13)
;
;2. IM2LOAD - LOADING A BLOCK OF SECTORS
; HL - ADDRESS
; D - TRACK (0..255)
; E - SECTOR (0..15)
; B - NUMBER OF SECTORS 1-#E0
; IN THE VARIABLE PAGE IS LOCATED
; PAGE TO LOAD TO
;
;3. LOADGRP - LOADING SEVERAL
; SECTOR BLOCKS:
; HL - ADDRESS OF INFORMATION ABOUT BLOCKS
; D - TRACK
; E - SECTOR
;
; I RECOMMEND FOR SWITCHING PAGES
;USE LKL PROCEDURE:; AT THE ENTRANCE: A - WHAT TO THROW IN
;PORT #7FFD
;IT SAVES INTO THE PAGE VARIABLE
;WHAT WAS BROUGHT INTO PORT #7FFD
;EITHER USE YOUR PROCEDURE, BUT
;DUPLICATE TO PAGE VARIABLE
;VALUE ENTERED IN PORT.
; YOU CAN PLACE IN THE SCREEN VARIABLE
;SCREEN NUMBER (0 OR 8)
;ONLY PLEASE NOTE THAT IF YOU WILL BE SHIPPING
;VIA #3D13 (E.G. FROM RAMDISC), THEN
;SCREEN WILL BE SETTED BY DEFAULT
;INSIDE THE TRDOS ITSELF TO EQUAL #00
;
;IN GENERAL, IT IS POSSIBLE TO CHANGE THE SCREEN
;REMOVE ALL. ;)
;
;DATA FOR LOADING THE WHOLE BLOCK
;CONSECUTIVE FILES, TOTAL SIZE
;WHICH DOES NOT EXCEED #E0 SECTORS.
;DB LENGTH_IN_SECTORS, PAGE:DW ADDRESS
LOAD1DAT DB #10,#10:DW #4000
DB #18,#17:DW #C000
DB #08,#10:DW #8000
DB 0
;Actually, LOADER PROCEDURES
;EVERYTHING IS PRETTY CHAMBER, BUT IT WORKS
;=====================================================
;TURN ON PAGE A
LKL PUSH BC
LD BC,#7FFD
LD (PAGE),A
OR 0
SCREEN EQU $-1
OUT(C),A
POP B.C.
RET
;CURRENT RAM PAGE
PAGE DB #10
;TYPE (0-3D13)
;LAG UP (0-F)
;LAG NEXT (0-F)
;SEC PER INT - NUMBER OF SECTORS-1 WHICH
;WILL BE READ BETWEEN PLAYS
;MUSON IN CASE TYPE=0. FOR
;RAMDISK MUST BE PUT 1, FOR
;SET SCREW 0, FOR REGULAR
;SET DISK DRIVE 7
;I.E. FROM RAMDISC IN ONE INTERNATIONAL TIME
;READ 2 SECTORS, AND FROM SCREW 1.
;FROM A REGULAR DISK DRIVE VIA 3D13;THE WILL NOT HAVE TIME TO READ IT IN 1 INT,
;THEREFORE 8 SECTORS NEED TO BE PUT
;ONLY SO THAT YOU DO NOT BRAKE SO MUCH
;MUZON.
DRIVEA: DB L3D2F,#0E,#02,#07
DRIVEB DB L3D2F,#0E,#02,#07
DRIVEC DB L3D2F,#0E,#02,#07
DRIVED DB L3D13,#00,#00,#01 ;2 SECTORS WHEN READING RAMDISK
;DRIVER SETUP
INSTALL LD A,(23798) ;TEK. DRIVE
AND 3
LD(drvnum),A
ADD A,A
ADD A,A
ADD A,DRIVEA
LD L,A
ADC A,DRIVEA/256
SUB L
LD H,A
;HL-SETTING TABLE
LD A,(HL) ;TYPE
INC HL
LD (TYPE),A
LD A,(HL);LAG UPPER TRACK
INC HL
LD (lagtrack),A
LD A,(HL);LAG NEXT TRACK
INC HL
LD DE,sectors
LD B,sectorsb-sectors
SETLGNT AND #0F
LD(DE),A
INC DE,A
DJNZ SETLGNT
LD A,(HL);SECTORS PER INT
INC A
LD (GRP3D13),A
RET
;int procedure
inter ex (sp),hl
ld(intjp+1),hl
ex(sp),hl
inc sp
inc sp
ld(intex+1),sp
ldsp,INTSP
push af
push bc
push de
push hl
exx
ex af,af'
push af
push bc
push de
push hl
push ix
push iy
LD A,(PAGE)
PUSH AF
;ISR body;HERE MAY BE THE CALL OF MUSIC ETC.
;BY JUST BLINKING THE CURB
LD A,0
CURCOLOR EQU $-1
INC A
AND 7
LD (CURCOLOR),A
OUT(254),A
POP AF
CALL LKL
;exit from ISR EITHER TO TRDOS OR TO
;RAM
ld a,(intjp+2)
cp #40
jr c, zabij
inex pop iy
pop ix
pop hl
pop de
pop bc
pop af
exx
ex af,af'
pop hl
pop de
pop bc
pop af
intex ld sp,#3131
ei
intjp jp #c3c3
zabij ;we are in trdos
ld hl,(intex+1)
dec hl
dec hl
ld(intex+1),hl
ld hl,#3d2f
ld(intjp+1),hl
jr inex
;-------------------------------------
;TABLE SHOWING HOW MUCH
;SECTORS NEED TO SHIFT WHEN CHANGING-
;SHIPPING THE HEAD ON 1-8 TRACKS
;DIRECTLY DEPENDS ON SECTOR SHIFT
;HA ON TWO PHYSICAL TRACKS
;IN PRINCIPLE, IT IS CONFIGED NORMALLY, CHANGE
;NOTHING IS NEEDED
;WHEN MOVE FORWARD
sectors db -1,0,1,2,3,4,5,6,7,8,9
;WHEN MOVE BACK
sectorsb db 2,1,0,-1,-2,-3,-4,-5,-6,-7,-8
esectors
;-------------------------------------
;read from disk via #3d13
ram_dsk ld (#5cf4),de
push hl
ld hl,(#5cc2);break protect
ld hl,#c9f1ld (#5cc2),hl
ex(sp),hl
dermo push bc
EI
halt
di
im 1
push hl
ld de,(#5cf4)
;READ MIN(GRP3D13,B) SECTORS
LD C,8
GRP3D13 EQU $-1
LD A,B
CP C
JR C,$+3
LD B,C
LD A,B
LD(_READED),A
ld C.5
PUSH BC
call #3d13
POP B.C.
pop hl
ld a,h
add a,B
ld h,a
im 2
ei
pop bc
LD A,B
SUB 0
_READED EQU $-1
LD B,A
JR NZ,dermo
pop hl
ld (#5cc2),hl
im 2
ei
ret
;IM 2 LOADER
;(C)2000-2001 VIVID & TIGGR FROM BW
;hl - read address
;de - track(0...255) & sector(0...15)
;b - number of sectors to read
;VARIABLE ramld EQUALS 0 WHEN READING
;THRU #3D2F, AND NOT 0, WHEN READING
;VIA #3D13 (FOR EXAMPLE FROM A SCREW OR
;RAMDISC)
IM2LOAD LD (FDESCR+2),HL
LD A,(PAGE)
LD(FDESCR+1),A
LD HL,FDESCR
LD(HL),B
JR LOADGRP
FDESCRDS 5
;LOADING A BLOCK OF CONSEQUENTIAL FILES
LOADGRP PUSH HL
LD B,0
LDGRP1 LD A,(HL)
OR A
JR Z,V.S.E.
ADD A,B
LD B,A
INC HL,HL,HL,HL
JR LDGRP1
VSE POP HL
JP LOADER
LD3D13 LD (#5CF4),DELD3D13_ LD A,(HL)
OR A
RET Z
INC HL
LD B,A
LD A,(HL)
INC HL
CALL LKL
LD E,(HL)
INC HL
LD D,(HL)
INC HL
PUSH HL
EX DE,HL
LD DE,(#5CF4)
CALL ram_dsk
POP HL
JR LD3D13_
;ЗАГРУЗКА ГРУППЫ ФАЙЛОВ
;DE-START TRACK
;HL-FILES DESCRIPTOR
;+0 - LENGTH (0-END OF TABLE)
;+1 - PAGE
;+2 - ADR
LOADER ld a,1
TYPE equ $-1
or a
jr z,LD3D13
EI
ld a,(#5cd6)
push af
PUSH HL
ld (trsec),de
ld (#5cf4),de
ld hl,(#5cc2);break protect
ld (runfile+1),hl
ld hl,#c9f1
ld (#5cc2),hl
push bc
push de
call posit ;track d
pop de
pop bc
;СОЗДАЕМ ТАБЛИЦУ СЕКТОРОВ
ld hl,sectb
xor a
mksectb ld (hl),a
inc l
jr nz,mksectb
ld a,d
rra
sbc a,a
and #10
or e
ld l,a
ld (startsec),a
and #ef
;HОМЕР СЕКТОРА ПОД ГОЛОВКОЙ
ld (secunh),a
ld c,b
;ЗАПОЛHЯЕМ ТАБЛИЦУ ДОРОЖЕК
ld de,tracktb
m00 ld c,0
m0 ld (hl),popytki
retrys equ $-1
inc l
inc cdjnz m1
ld a,c
ld (de),a
jr m2
m1 ld a,l
and 31
jr nz,m0
ld a,c
ld (de),a
inc de
jr m00
;--------------------------------------
m2 ld a,e
sub tracktb256
ld (hitrk),a
inc a
ld (osttracks),a
xor a
ld (direct),a
ld (lowtrk),a
ld (curtrk),a
;ЗАПОЛHЯЕМ ТАБЛИЦУ АДРЕСОВ
POP HL
LD E,0
FILLADT LD A,(HL)
INC HL
OR A
JR Z,F_OK
EXA
LD A,(HL) ;PAGE
LD (FPG),A
INC HL
LD C,(HL)
INC HL
LD B,(HL)
INC HL
EXA
EX DE,HL
FILL1 LD H,ADRTB/256
LD (HL),0
FPG EQU $-1
INC H
LD (HL),C
INC H
LD (HL),B
INC L
INC B
DEC A
JR NZ,FILL1
EX DE,HL
JR FILLADT
F_OK
;--------------------------------------
load0 ld hl,sectb
secunh equ $-2
;поиск ближайшего несчитанного сектора
;в таблице
ld a,l
and #e0
ld d,a
sseek ld a,(hl)
ld e,l
or ajr nz,found
ld a,l
add a,0
lagtrack equ $-1
and #0f
or d
or #10;up side
ld l,a
ld a,(hl)
or a
jr nz,found
ld a,e
inc a
and #0f
or d
ld l,a
jr sseek
found ld a,e
inc a
and #0f
or d
ld (second),a
ld a,l
ld (nowread),a
;waiting for you
and 16
or 0
drive number equ $-1
or #2c
xor #10
call outff
;was a snowflake для чтеия
ld a,l
and #0F
ld e,a
;waiting for a snowflake
ld a,l
sub 0
startsec equ $-1
LD L,A
LD H,ADRTB/256
LD A,(HL)
INC H
CALL LKL
LD A,(HL)
INC H
LD H,(HL)
LD L,A
LD A,E
call readsec;subject readsec a
;с текущей дорожки
;cf=1 slightly slightly
ld hl,sectb
nowread equ $-2
jp nc,readoc
;oшибка чтения:
dec (hl)
jr nz,load0;small size
;subjects
;Exclusive snowflake snowflakes
;секторов на данной дорожке.ld a,(retrys)
ld(hl),a
ld e,a
ld a,l
and #e0
ld l,a
xor a
ld b,32
reinit cp (hl)
jr z,dontinit
ld(hl),e
dontinit inc l
djnz reinit
;how many unread tracks
ld a,0
osttracks equ $-1;tracks left.
dec a ;last?
jr z,load0 ;nowhere further
;let's see where to move.
polzem ld a,255
direct equ $-1
or A
ld a,0
curtrk equ $-1
ld b,a
jr z,forward
cp 0
lowtrk equ $-1
jr nz,nchdir
xor a
ld (direct),a
ld a,b
jr forward1
nchdir
;we are looking for the nearest path towards the street
;change track numbers
add a,tracktb256
ld l,a
adc a,tracktb/256
sub l
ld h,a
xor a
ldc,a
seeklow dec hl
dec b
inc c
cp(hl)
jr z,seeklow
ld a,b
ld(curtrk),a
;c-offset
ld a,c
add a,sectorsb-1
ld l,a
adc a,0+(sectorsb-1)/256
sub l
ld h,a
ld a,b
rrca
rrca
rrca
ld e,ald a,(secunh)
ADD A,(HL)
and 15
add a,e
ld (secunh),a
nostbw ld a,b
add a,a
ld de,#1111
trsec equ $-2
add a,d
ld d,a
call posit
jp load0
forward cp 0
hitrk equ $-1
jr nz,forward1
ld a,#ff
ld (direct),a
ld a,b
jr nchdir
forward1 add a,tracktb256
ld l,a
adc a,tracktb/256
sub l
ld h,a
xor a
ld c,a
seekhi inc hl
inc b
inc c
cp (hl)
jr z,seekhi
ld a,b
ld (curtrk),a
;c-offset
ld a,c
add a,sectors-1
ld l,a
adc a,0+(sectors-1)/256
sub l
ld h,a
ld a,b
rrca
rrca
rrca
ld e,a
ld a,(secunh)
add a,(hl)
and 15
add a,e
ld (secunh),a
nostf ld a,(trsec+1)
add a,b
add a,b
ld d,a
call posit
jp load0
;БУФФЕР ДЛЯ ХРАHЕHИЯ ЧИСЛА СЕКТОРОВ
;HА ФИЗИЧЕСКОЙ ДОРОЖКЕ
tracktb ds 8
readok
;пометили сектор как прочитанный
ld (hl),0;increase the current sector and track
ld hl,#5cf4
ld a,(hl)
inc a
and 15
ld(hl),a
inc hl
jr nz,$+3
inc(hl)
;reduce the number of sectors that
;must be read from this track
ld a,(curtrk)
ld b,a
add a,tracktb
ld l,a
adc a,tracktb/256
subl
ld h,a
dec (hl)
jp nz,load0;read further
;we check whether the read
;track last
ex de,hl
ld hl,osttracks
dec (hl)
ex de,hl
jr z,konets;read
;completely
;compress the boundaries if necessary
ld a,(lowtrk)
cp b
jr nz,nosqueezelow
ldc,a
xor a
squeezel inc hl
inc c
inc b
cp(hl)
jr z,squeezel
ld a,b
ld (lowtrk),a
xor a
ld (direct),a
jp polzem
nosqueezelow
ld a,(hitrk)
cp b
jp nz,polzem
ldc,a
xor a
squeezeh dec hl
inc c
dec b
cp(hl)
jr z,squeezeh
ld a,b
ld (hitrk),a
ld a,#ffld (direct),a
jp polzem
konets pop af
ld (#5cd6),a
runfile ld hl,#2121
ld (#5cc2),hl
ret
;reset VG93 (once for crooked cars),
;or the first time you access this
;drive
posit ld a,#3e
or a
jr z,track
xor a;next time
ld(posit+1),a
ld a,(drvnum)
or #3c
call outff
ld a,%00001000
call out1f
call gundos
track ld a,d
srl a
ld (pipisa),a
ld c,#7f
call outc
ld a,%00011000
call out1f
jr gundos
outff ld c,#ff
outc ld ix,#2a53
jr dos
stepbkw ld hl,pipisa
dec (hl)
ld a,%01111100
jr out1f
stepfw ld hl,pipisa
inc(hl)
ld a,%01011100
out1f ld ix,#2fc3
jr dos
gundos ld ix,#3ef5
dos push ix
jp #3d2f
deby db 1;needed for polling #1f
;read sector with current. roads
readsec if 0
ld hl,0
aaaa equ $-2
inc hl
res 6,h
ld (aaaa),hl
ld a,(hl)
add a,a
ret
endif
ld (address),hl
inc ald c,#5f;physical sector number
call outc;to sector register
xor a
ld (#5cd6),a
ld hl,retdos;actions for
push hl ;for control
ld hl,deby ;for
push hl ;correctness
ld bc,#017f ;reading
ldhl,#2121
addresses equ $-2
ld ix,#2091
jr dos
retdos ld a,10
ld (#5cd8),a
ld de,0
pipisa equ $-1
ld ix,#2740
call dos
ld a,(#5ccd)
and %01111111
ret z
ld a,(#5cd6)
neg
ret
ENDCODE
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Bye, All.
WBR, Vivid^Brainwave.