YOU CAN CORRECTLY CONNECT THE PRINTER CONTROLLER TO THE speccy USING
BY USING K589AP16, K555APb. THIS ELIMINATES THE COMPUTER
RA WHEN TURNED ON DUE TO THE PRESENCE OF A CONTROL SIGNAL ON THE DATA BUS
RA 'PRINTER IS MISSING' OR 'PRINTER BUSY'. MUKPOC IS APPLIED
CHEMA KPS8OVA86 (FIGURE 1). INSTEAD OF K5SSLA9 YOU CAN USE BO-
LEADER COMMON-KSS5LAZ.IN THE TEXT OF MOVEMENT OF THE DRIVER FOR
THIS CONTROLLER HAS A SIGNIFICANT INACCURACY WHICH REVEALS -
IF THE PRINTED STRING CONTAINS MORE THAN 65 CHARACTERS (LOST)
THERE IS 1 CHARACTER AND AN EXTRA 'BLANK LINE' IS PRINTED).FOR ITS YCTPA-
IT IS ENOUGH TO SWAP THE OPERANDS newline AND conto IN
THE FOLLOWING FRAGMENT OF THE PROGRAM:
ld bc,conto-base
add hl,bc
ex(sp),hl
jr newline
TO USE THE DESCRIBED DRIVER WHEN OPERATING WITH tlw2, SUPPLY
THE PRINTER MAINTENANCE PROGRAM CAN BE SIGNIFICANTLY SIMPLIFIED:
prn ld hl,base
cp {7f +5B $$$$$$$$$$$$$$$$$$$$
jr nz,sym ddS
ld a,{23 KPS8OVA86 & & & & & & r19-r14jr print К& &%%%%%%& & & & & & & (1К)
sym jr c,print &$$$1& ` & &19$$$&$&$&$&$&$$$$&К
sub 165 z&$$$2&%%%%%%&18$$$$$&$&$&$&$$$$&
jp nc,{0c10 x&$$$3& ` & &17$$$$$$$&$&$&$$$$&d
print ld d,a &$$$4& ` & &16$$$$$$$$$&$&$$$$&d
wait call {1f54 d&$$$5& `ЕП& &15$$$$$$$$$$$&$$$$&1
jr c,cont1 a&$$$6& ` & &14$$$$$$$$$$$$$$$$&
rst 8 t&$$$7& ` & &13$$$$$$$$$$$$$$$$&
defb {14 a&$$$8& ` & &12$$$$$$$$$$$$$$$$&
cont1 in a,({fb) &$`$$&$&
add a,a $$$$$$$9&-` & &
ret m & $$11&+` & & РИСУНОК 1
jr nc,wait & & %%%%%%%%
ld a,d & &
out ({fb),А & &$$$ К ВЫВОДУ 8 dd2
ret &
&$$$$$$$ К ВЫВОДЫ 3dd2
----------------------------------------------------------------
DEVELOPMENT OF CONTROLLER D-A
DEVELOPMENT BY WESTERN DIGITAL - INTERFERENCE-PROOF DIGITAL CIRCUIT
PLL-BECAME WIDELY KNOWN IN KHARKOV EARLIER THAN IN OTHER CITIES
CHILDREN IN THE CIS THANKS TO THE PROMPT RESPONSE OF V.M.G. And B.A.E.
BASED ON THE NEEDS OF THE MARKET.IN 1992, THE SCHEME TOOK FIRST PLACE IN
SALE, IT IS INCLUDED IN ALMOST ALL NEW DEVELOPMENTS
KHARKIV RAIO LOVERS. THE COMPANY'S ADVERTISING brochure APPROVES,
THAT THIS SCHEME INCREASES THE RELIABILITY OF READING DISK INFORMATION
NO LESS THAN 10 TIMES. EXPERIENCE IN USING A CIRCUIT WITH CONTROLLERS
'ECHO', 'betadisk', 'pentagon' AND OTHERS CONFIRM THIS INFORMATION -
TION IN 90 PERCENT OF CASES. THE DIFFERENCE IS ESPECIALLY NOTICEABLE WHEN WORKING WITH
LOW-QUALITY DISK DRIVES AND DISKETTES.
$$$$$$$$$ $$$$$$ r1 10k MIC FIRMWARE
&`. &`&. & ROSCHEMES 556 RTC
& ` & ` & & $$$$$ $$$$$ C . +5v PUBLISHED IN
& ` & ` C & & &. &&. & & . wf/de MAGAZINE 'RADIO'
&`556& ` O &555 & &555& &555& . rclk AMATEUR' IN BUT-
& ` & ` P & TM9& &TM2& &LAZ& & . -rawr AT LEAST 3 FOR 1993
& `PTC& ` R & & & & & & r . -rdata YEAR (PAGE 6)
& ` & ` O & & & & & & 2 . 8 mhz
& ` & ` & & & & & & & . gnd
%%%%%%%%% %%%%%% %%%%% %%%%%
r3...r6 1k
4 x 1K!
IF YOU NEED A DIAGRAM FOR THIS IMPROVEMENT, WRITE AND I WILL GIVE IT TO YOU
I WILL SEND (FREE!), AND ALSO HAS A sound drive by flash!
----------------------------------------------------------------
AND NOW I WOULD LIKE TO TELL YOU ABOUT THE SHADOW ROM tr-dos!
SHADOW ROM tr-dos CONNECTS TO THE MAIN ROM OF THE COMPUTER WHEN
Z-80 ACCESSING CERTAIN MEMORY ADDRESSES. ONE OF SUCH ADDRESSES
PECOB-ADDRESS {3d13.IF TR-DOS' YOU NEED TO CONTACT THE MAIN
MU ROM, IT DOES THE FOLLOWING:
-BTHE STACK IS PUT THE RETURN ADDRESS TO THOSE PARTS OR MODULES tr-dos.
-THE ADDRESS OF THE REQUIRED SUBPROGRAM FROM THE MAIN ROM IS PUT ON THE STACK
-SHADOW ROM IS DISABLED.
-GOING TO ADDRESS 23746.
-THE RET INSTRUCTION IS LOCATED AT THIS ADDRESS, SO FROM THE STACK
THE ADDRESS OF THE SUBPROGRAM IN THE MAIN ROM IS TAKEN AND IT STARTS.
-RET INSTRUCTION AT THE END OF THE PROGRAM WILL CAUSE A JUMP BACK-IN THE SHADOW-
VOE ROM tr-dos'A.
THE PROVIDED EXAMPLE SHOWS HOW YOU CAN REFER TO tr-dos
SO TO ALLOW HER TO CLEAR THE SCREEN AND SHOW HER MESSAGE
AT THE BOTTOM OF THE SCREEN. INSTEAD, tr-dos DISPLAYS IN THE 'MESSAGE' WINDOW
DEFINITION OF THE SYSTEM, APPLIED WINDOW INTERFACE. IN AN EXAMPLE
THERE IS AN APPEAL TO AN UNDEFINED WINDOW INTERFACE HERE.
YOU CAN JUST INSTALL YOUR PROGRAM WITH A SIMILAR VALUE
MAKE YOUR SPECIAL CALLS TO THE SITES OF CALLING THESE PROCEDURES C
SIMILAR FUNCTIONS. IN THIS CASE, THE CALL TO tr-dos IS SEPARATED
IN 3 STAGES:
1. PREPARATION OF THE OPERATION: INTERCEPTOR INSTALLATION.
2.DIRECT CALL tr-dos BY {3D13 (WITH RETURN TRANSITION)
3. COMPLETION OF THE OPERATION: REMOVAL OF THE INTERCEPTOR.
SO, STAGE 1—INTERCEPTOR INSTALLATION:
pospre sub a
ld (rstflg),a
ld hl,posw
ld (rstptr),hl
call im1
posswp ld hl,dos st
ld de,23746
ld bc,3
swap2 ld a,(de)
ldi
dec hl
ld (hl),a
inc hl
jp pe,swap2
ld hl,(23633)
ld c,(hl)
inc hl
ld b,(hl)
ld de,(dos oh)
ld (dos oh),bc
ld (hl),d
dec hl
ld (hl),e
ret
ВТОРОЙ ЭТАП:
dos push af
ld (iy),-1
sub a
ld (23823),a
ld (23824),a
pop af
call {3Д13
ld a,(23823)
and a
ret z
scf
ret
dos st jp dosend
dos hl defw 0
dos bc defw 0
dos oh defw dos rstdosend ld (dos hl),hl
ld (dos bc),bc
pop bc
push af
and a
ld hl,{Odбb
sbc hl,bc
jr z,dos cls
ld hl,{1601
sbc hl,bc
jr z,dosing
pop af
push bc
ld hl,(dos hl)
ld bc,(dos bc)
ret
posign pop af
ret
rstflg defb 0
rstptr defw dosw
dosclspop af
ld hl,dosw
ld de,dosw+1
ld bc,5*21-1
ld (hl),{ff
ldir
ld hl,dosw
ld (rstptr),hl
ld a,(rstflg)
and a
ld a,28
call z,open
ld a,-1
ld (rstflg),А
jp reddraw
dosrst push bc
push de
push hl
ld hl,(rstptr)
ld (hl),a
inc hl
ld (rstptr),hlcall text-n ;UPDATE TEXT IN WINDOW
pop hl
pop de
pop bc
ret
dosend ld (iy),-1
caLL dosswp
ld a,(rstflg)
and a ;IF THE WINDOW SAYS tr-dos OPENS
call nz,close ;THEN CLOSE IT
ret
THUS, IF tr-dos WANTS TO ISSUE DURING THE WORK PROCESS
MESSAGE disk error OR read only,PROGRAM FIRST
IS TRYING TO CLEAR THE SCREEN. THIS ATTEMPT WILL BE DETECTED by dosend
AND INSTEAD OF CLEARING THE SCREEN, A MESSAGE WINDOW WILL BE DISPLAYED
tr-dos AND ITS CLEARING.THEN tr-dos WILL TRY TO OPEN THE STREAM
'k', BUT THIS ATTEMPT WILL BE INTERCEPTED AND IGNORED. IN RE-
AS A RESULT, THE TR-DOS MESSAGE APPEARS IN BEAUTIFUL MULTICOLOR
THE WINDOW IS IN THE MIDDLE OF THE SCREEN, NOT AT THE BOTTOM. AFTER COMPLETING THE LAST CONCLUSIONS
CALLS IN tr-dos THE WINDOW WILL CLOSE (DURING dosend).$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
p.p.s VOROZHKIN ALEXANDER, BAZHENOV STAS
Do it yourself - printer controller for ZX Spectrum. Improvement of the PLL drive controller.
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