Author: Sergey Kolotov, SerzhSoft
__________________________________________
NEW "40 BEST PROCEDURES"
In 1992, in the pages of a ZX-REVIEW
published an abridged translation of the book by J.
Hardman and E. Hyuzon "top 40 procedures."
The publication has caused the most
rave chi
Tutelo, because many in the
rank sinkleristy with its
by finally able to
overcome all difficulties
"Barrier machine code."
But it is exactly five
years, and old-timers ZX-REVIEW
was surprised to notice in
the first issue for 1997 is painfully familiar
name.
All of the many reasons so convincingly set forth INFORKOMOM
course largely correct. But in my (and not
only my) opinion, they did not give
People magazine publishers the right to spend
precious pages ZX-REVIEW print already
published at the time of the material.
Instead of heading a "retro" is much more useful
and current could be introduced to "remake". And it does not
print just the old, well-worn materials, and treat them
more deeply, to give examples of more effective implementation
of programs and individual procedures.
Get at least the same "40 procedures." Yes,
This work is very useful for beginners. But a little more
experienced experts assembler will notice that the more of
obemu reducible authors procedure, then invariably, it has more
disadvantages more effectively implemented, has
greater number of "extra" commands ... Yes
Some "better procedures" are reduced
more than twice! And more: Comments
programs are for themselves listings that are very difficult to
understand "what exactly happens when the procedure
at some stage. "Of course, a description of the type" C
register is copied into the register B ", but such is the
meaning, which behind this is not always clear ...
It will be presented libraries, in
that has integrated graphics procedure to rewrite the principle
of "forty of the best." Memory footprint decreased from 1,444
bytes to 861 bytes! Each procedure commented in detail most of
its listing, so to speak - on the spot. "
Listing and hex dump.
Many of the procedures in their work requires
some pre-defined values -
constants. Under these values are allocated a special area of
memory addressable tag CONSTS. In this case indicates CONSTS
address 23296, but of course this address
You can change to any other. The length of the constants of 8
bytes. If any of the procedures, none of the constants does not
change. Otherwise, it would have to call them Variable ...
The procedures that manipulate the coordinates of points on
the screen ostchet is in contrast to BASIC is not a bottom-up,
and vice versa - Top-down. Such a reading of coordinates is
much more convenient and is used in many other computers. Now
you can specify Y coordinate from 0 to 191 (instead of 175)
ie it is possible to specify the coordinates of points on the
screen that are in the bottom two rows to be allocated by error
messages. When counting the same bottom-up, the maximum
Y-coordinate is Y = 175, and to the lower two strings do not
get.
BRIEF DESCRIPTION OF PROCEDURES:
1. ASRL_LF - a procedure shifts the entire
screen attributes (color) to the left. The right column is
filled with an attribute of the cell to at CONSTS (23,296). The
length of the procedure, 22 bytes (was - 23 bytes). -Translated
under the address 62000 (HEX: # F230).
2. ASRL_RG - a shift of the entire screen to the right
attributes. The left column is filled with an attribute of
CONSTS. The length of the procedure, 21 bytes (19 bytes).
Located at 62022 (# F246).
3. ASRL_UP - shift up the whole screen attributes. The
bottom line of the attribute is populated from CONSTS. The
length of the procedure, 19 bytes (21 bytes). Address: 62043 (#
F25B).
4. ASRL_DN - shift the entire display attributes down. The
upper line is filled with an attribute of CONSTS. Length: 20
bytes (21 bytes). Address: 62062 (# F26E).
5. SSRL_LF - a shift of the entire screen to the left
one character (graphic). The right column
familiarity is cleared. Length of 20 bytes (21
bytes). Address: 62082 (# F282).
6. SSRL_RG - a shift of the entire screen to the right
one character. The left column familiarity
cleared. Length of 19 bytes (22 bytes). Address: 62102 (# F296).
7. SSRL_UP - translation of the whole screen up
one character. The bottom line of familiarity
cleared. Length 55 bytes (68 bytes). Address:
62,121 (# F2A9).
8. SSRL_DN - a shift of the entire screen down
one character. The top line of familiarity is cleared. Length
55 bytes (73 bytes). Address: 62,176 (# F2E0).
9. PSRL_LF - a shift of the entire screen to the left
one pixel (graphics). The right column
pixel is cleared. Length of 16 bytes (17
bytes). Address: 62231 (# F317).
10. PSRL_RG - a shift of the entire screen to the right
one pixel. The left column of pixels
cleared. Length 17 bytes (17 bytes). Address:
62,247 (# F327).
11. PSRL_UP - translation of the whole screen up
one line of pixels. Bottom row of pixels is cleared. Length of
38 bytes (91 bytes). Address: 62264 (# F338).
12. PSRL_DN - a shift of the entire screen down
one line of pixels. The upper line
pixel is cleared. Length of 38 bytes (90 bytes). Address: 62302
(# F35E).
13. SCR_MRG - merge two images
(Graphics, on the basis of OR). Double-byte
constant at CONSTS must contain the address of the placement of
the second picture in memory (overlay). The result is put on
the screen. The length of the procedure, 17 bytes (Previously -
21 bytes). Address of accommodation: 62,340 (# F384).
14. SCR_INV - invert the screen
(Graphics, on principle). All the pixels change their value to
the opposite. The length of the procedure, 12 bytes (was - 18
bytes). Address: 62357 (# F395).
15. SINV_UD - invert symbol
vertically. Arrow pointing up
is directed downward, and vice versa.
In the double-byte variable at CONSTS
must contain the address of a variable character. The length of
the procedure, 20 bytes (or was). Address allocation: 62369 (#
F3A1).
16. SINV_LR - invert symbol
horizontally. Arrow pointing left, is directed to the right,
and vice versa. In the double-byte variable at CONSTS must
contain the address of a variable character. The length of the
procedure, 17 bytes (was - 19 bytes). Address allocation: 62,389
(# F3B5).
17. SROTATE - rotate the character in a clockwise direction
by 90 degrees. In the double-byte variable at CONSTS must
contain the address of a variable character. Length 26 bytes
(previously - 42 bytes). Address: 62406 (# F3C6).
18. ACHANGE - change the attributes of all symbols of the
screen. Bit operation. In a cell at CONSTS should contain the
mask bits: Bits that are installed in the mask are the
attributes same, and the bits that are masked
null value - would have zero
value and the attributes (operations and (not
"Since "!)). In a cell at CONSTS +1 must
bytes to be included whose bits
will be introduced in all the attributes of the screen, ie,
If this byte is a bit turned on,
then it will be installed in all the attributes
(OR operation). The length of the procedure 16 bytes
(21 bytes). Address: 624320 (# F3E0).
19. AREPLC - search the attributes of a specific value and
replace each found a new attribute value. In cell at CONSTS
should contain byte value to be replaced (that look). In a cell
at CONSTS +1 should be the value of the substitute bytes (the
replace). The length of the procedure, 18 bytes (22
bytes). Address: 62448 (# F3F0).
20. PAINT - fill certain
screen area, bounded by a line of pixels (fill). The starting
point is given by placing it at the X
CONSTS, and the coordinates of Y - to the address
CONSTS +1. If the Y coordinate greater than 191 or
point in these coordinates is already installed, the program is
interrupted by an emergency. This procedure is not moveable
because of the challenges procedures POINT. When shading is
actively used by the stack - it stored the coordinates of the
line fills. When painted over a large area of complex shapes,
and need more space in RAM - between the end of BASIC-program
and address set by the operator CLEAR
(The contents of the system variable RAMTOP).
If memory space is not enough, you can
crash. The procedure takes 88
bytes, and together with the procedure POINT - 123
bytes, which is more than half
length of the procedure in 1992 (263 bytes!).
Address PAINT: 62,466 (# F402).
21. POINT - address calculation point in
screen, given the coordinates and check
state this point (ON / OFF). Attention!
This procedure can be used
only from the machine code (starting from BASIC will give
nothing). Before calling, you must install the register E X
coordinate (0 .. 255), and in case D - Y coordinate
(0 .. 191) tested the point. The output of the procedure set in
the register pair HL byte address on the screen, which is
point, and in case C - the point in this mask byte (one bit set
in the unit). Depending on how turned on a point or
No flag is set zero: Z - point
not included, NZ - point is included. If
point is set (apparently), the register A
(Battery) is identical in meaning
Register with C, and if the point is not set, then A is reset.
Register B is always exit from the procedure is zero. The
length of the procedure, 35 bytes (the original would occupy
about 70 bytes). Address allocation: 62,554 (# F45A).
22. PFIGURE - construction of any previously
a certain figure (pattern) on the screen.
Coordinates of the initial (starting) points are given the same
procedure PAINT. Template set in the BASIC string variable A $
(You can change to any other, slightly
adjusting assembly listing or
dump). A string of characters is as follows
format (a bit different from the original):
"5" - to reduce the X-coordinate
"6" - to increase the Y-coordinate
(The count goes from top to bottom)
"7" - to reduce the Y-coordinate
"8" - to increase the X-coordinate
"0" - to put the point
Any other characters inogriruyutsya.
If the string variable does not exist
or does not contain any information that
program interrupts their work. Control
for withdrawal of the initial Y-coordinate is not because
part of the figure can still be seen. Therefore, checking out
off the screen introduced in the cycle of forming a pattern.
Ability to 'wrap-round' is preserved, ie
still, when you exit X-coordinates for
the left side of the screen, the pattern appears
right, and vice versa. The procedure is not moveable. Length
PFIGURE: 98 bytes, and with used routine POINT - 133
bytes, which is still much smaller than the original (196
bytes). Address: 62589 (# F47D). If the "open" procedure call
POINT, then PFIGURE will be moved and will occupy about 125
bytes!
23. PSCALER - copy of the screen
in another region of the same screen with a possible increase
up to X and / or Y. Constants are used:
Address Name Comment
CONSTS X1_OLD one of two primary
X-coordinate pryamoug-ka
CONSTS +1 Y1_OLD one of two primary
Y-coordinate pryamoug-ka
CONSTS +2 X2_OLD one of two primary
X-coordinate pryamoug-ka
CONSTS +3 Y2_OLD one of two primary
Y-coordinate pryamoug-ka
CONSTS +4 XSCALE magnitude larger
to X
CONSTS +5 YSCALE magnitude larger
on Y
CONSTS +6 X_NEW coordinates of the left upper
On the corner of the screen,
CONSTS +7 Y_NEW which is
copy
Coordinates of the initial rectangle
Copy set in the constants
X1_OLD, Y1_OLD, X2_OLD, Y2_OLD, moreover,
can be arranged in any order. The procedure itself will
determine the smallest and largest coordinates. Emergency exit
procedures are in the following cases:
1. XSCALE = 0 - zoom scale on the X
zero
2. YSCALE = 0 - zoom scale on the Y
zero
3. Y_NEW> 191 - the new Y coordinate vyho
leads off the screen
4. Y1_OLD> 191 - Y1 coordinate of the old you
goes beyond the screen
5. Y2_OLD> 191 - Y1 coordinate of the old you
goes beyond the screen
Like the original, the program does not
control that would check the possibility
placement of the new picture on the screen. If
this does not work, something might happen
failure.
When performing the procedure at first throws a stack
bitmaps copied rectangular screen and then draws it to the new
location, increasing necessary. Therefore, if the stack is not
enough space on it, as in the procedure PAINT can happen
freeze, reset, Error ...
If you want to copy a piece of the screen was the same size
as this, it is necessary to establish the scale of 1:1 - Add a
constant XSCALE and YSCALE edinichki. When you double the
amount there should be dvoechki, and so on ...
The procedure is not moveable from the use of sub POINT.
PSCALER occupies 174 bytes, and with POINT - 209
bytes. In any case, it is much less
than the original - 335 bytes! Address of accommodation:
62,687 (# F4DF).
So, here you are, and got acquainted with a new
implementation of "best procedures." But I advise you not
delude ourselves - some of the procedures it should be possible
to reduce more ... However, in this will inevitably have to
sacrifice something: speed of execution, or transferability,
Finally, just the time spent. I hope that the figures in this
article, the program will be useful, at least - Maybe they just
touch up on you any thoughts ... Beginners can
try to compare the procedure in 1992 with
new, learn the principles of creating a more
effective programs, tools for the integration of many different
procedures in one large library of ... Experienced programmers
also may get a lot of fun, laughing mischievously given work.
But it is also a plus: amuse people - a very necessary work! So
I wish to all readers:
Enjoy working with LOVED SPECCY!
;----------------------------------------;
, 40 New Best Routines (graphic);
; (C) SerzhSoft, Shadrinsk, may-june, 1997;
; Old length: 1444 b - new length: 861 b;
;----------------------------------------;
ORG 62000; address assembles
tion
;----------------------------------------;
CONSTS EQU 23296; address of the buffer concentration
constants (8 bytes)
;----------------------------------------;
; Shift attributes to the left (22 <= 23)
;----------------------------------------;
ASRL_LF
LD DE, # 5800; DE = address of first
Vågå bytes
Attributes
LP_ASLF LD H, D; copied
DE to HL
LD L, E; and increased
HL per unit
INC HL; HL = address of the second
rogo bytes
Attributes
LD BC, # 001F; <line length
attributes> - 1
LDIR; line shift
Attributes
left
LD A, (CONSTS); color filling
of after
shift
LD (DE), A; set
new attribute
INC DE; transition to
whether
Research from the bottom
LD A, D; if the attributes
has ended
CP # 5B; and we have come across
a buffer
Printer
JR C, LP_ASLF; then STOP, ina
Th shift
more
RET; exit from the
procedure
;----------------------------------------;
; Shift attributes to the right (21 <= 23)
;----------------------------------------;
ASRL_RG
LD DE, # 5AFF; address last
He bytes
Attributes
LP_ASRG LD H, D; copied
DE to HL -
LD L, E; Last
byte lines
Attributes
DEC HL; penultimate
byte lines
Attributes
LD BC, # 001F; <line length
attributes> - 1
LDDR; line shift
Attributes
right
LD A, (CONSTS); color filling
of after
shift
LD (DE), A; set
new attribute
DEC DE; transition to
whether
SRI top
BIT 3, D; if we all
even in the attributes
max,
JR NZ, LP_ASRG; then repeat
cycle for the lyrics.
line
RET; exit from the
procedure
;----------------------------------------;
; Shift attributes up (19 <= 21)
;----------------------------------------;
ASRL_UP
LD HL, # 5820; address of the second
Line attributes
Comrade
LD DE, # 5800; address of the first
Line attributes
Comrade
LD BC, # 02E0; move:
23 lines of
32 bytes
LDIR; shift 23
bottom line
Up
LD A, (CONSTS); color for
complement the lower
her line
LP_ASUP LD (DE), A; set
new attribute
INC E; if filled
Does the whole village
glacial line
JR NZ, LP_ASUP; (E = 0) then
interrupt
cycle
RET; exit from the
procedure
;----------------------------------------;
; Shift attributes down (20 <= 21)
;----------------------------------------;
ASRL_DN
LD HL, # 5ADF; address of the end
second-line
bottom
LD DE, # 5AFF; address of the end
the lowest
line
LD BC, # 02E0; move: 23
Line 32
Byte
LDDR; shift 23
top line
down
LD A, (CONSTS); color for
complement ver
hney line
LP_ASDN LD (DE), A; set
new attribute
DEC E; if reached
the very first
first byte
JR NZ, LP_ASDN; of Atri
casks (E = 0);
then STOP
LD (DE), A; and establishes
Vai this byte
RET; exit from the
procedure
;----------------------------------------;
; Shift left one character (20 <= 21)
;----------------------------------------;
SSRL_LF
LD DE, # 4000; top domains
Graphic Tee
LP_SSLF LD H, D; address of the first
LD L, E; byte line
INC HL; address of the second
byte lines
LD BC, # 001F; how many bytes
shift
LDIR; line shift
Left on 1
bytes
XOR A; resets ak
kumulyator and
have brought
LD (DE), A; the last
(Right) bytes
line
INC DE; transition to
whether
line (bottom)
LD A, D; if the attributes
CP # 58; "still have not seen
give, "
JR C, LP_SSLF; then repeat
cycle for the lyrics.
line
RET; exit from the
procedure
;----------------------------------------;
; Right shift by one character (19 <= 22)
;----------------------------------------;
SSRL_RG
LD DE, # 57FF; Last
bytes of
Graphics
LP_SSRG LD H, D; address last
He bytes
LD L, E; current line
DEC HL; address before
last
Byte
LD BC, # 001F; shift: 31
bytes
LDDR; line shift
graphic to the right
XOR A; clear the accumulative
mulyator and for
so
LD (DE), A; first (le
vy) bytes are
Booths line
DEC DE; transition to
whether
Institute of higher
BIT 6D; if we have
not "come across"
in ROM
JR NZ, LP_SSRG; we continue
spin cycle
RET; exit from the
procedure
;----------------------------------------;
; Shift up one character (55 <= 68)
;----------------------------------------;
SSRL_UP
LD DE, # 4000; top of the screen
Noah region
LP_SSU1 PUSH DE; store ad
interest on line
stack
LD BC, # 0020, in line - 32
Byte
LD A, E; The register DE
is hell
res
ADD A, C; top Do
Research Institute. In Regis
triangle
LD L, A; HL should
get the hell
res
LD A, D; line, lying
ing from below
step 8.
JR NC, GO_SSUP; To this end,
Register E
we add 32
ADD A, # 08; and records
L. If proiGO_SSUP LD H, A; zoshlo
transition complement, then
H = D +8
LDIR; transfer of one
line (32
bytes)
POP DE; recovered
Vai address
start line
LD A, H; check: a
whether it is time
We zakrug
CP # 58; lyatsya? (Ne
renesli all
1923 series)
JR NC, LP_SSU2; if so,
transition to
cleanup
INC D ;------------;
LD A, D;
DOWN_DE
AND # 07; standard
sequence
sequence
JR NZ, LP_SSU1; commands
transition to
line down
LD A, E; on-screen
region
ADD A, # 20, (to register
DE)
LD E, A;
JR C, LP_SSU1; input:
DE - Address
line
LD A, D; Output:
DE - Address
line below
SUB # 08; used
battery
LD D, A;
JR LP_SSU1 ;------------;
LP_SSU2 XOR A; cleaning Accu
mulyatora
LP_SSU3 LD (DE), A; with him on
power -
INC E; cleaning of one
line image
tion
JR NZ, LP_SSU3; total: 32
Byte
LD E, # E0; transition to
next
INC D; (lower) if
Research images
of
BIT 3, D; filled
all subsequent
tions series?
JR Z, LP_SSU2; if not,
continue
fill
RET; exit from the
procedure
;----------------------------------------;
; Shift down by one character (55 <= 73)
;----------------------------------------;
SSRL_DN
LD DE, # 57FF; address last
He bytes
Graphics
LP_SSD1 PUSH DE; retained hell
res end if
SRI
LD BC, # 0020; the length of one
line image
tion
LD A, E; in register HL
SUB C; get the hell
res
LD L, A; end of the line
LD A, D; overlying
JR NC, GO_SSDN; starting with
step
SUB # 08; of 8 pixels
(Lines):
GO_SSDN LD H, A; HL = how to
feast; DE =
where
LDDR; transfer of one
Line graphs
POP DE; recovered
Vai address
end of line
BIT 6, H; if we have already
not in the screen,
JR Z, LP_SSD2; then go
to clean
LD A, D ;------------;
DEC D; UP_DE
AND # 07; standard
sequence
sequence
JR NZ, LP_SSD1; commands
transition to
line up
LD A, E; in screen
area (for
SUB # 20; register DE)
LD E, A;
JR C, LP_SSD1; input: DE
- The address line
LD A, D; output: DE
- The address line
above
ADD A, # 08; used
battery
LD D, A;
JR LP_SSD1 ;------------;
LP_SSD2 XOR A; cleaning Accu
mulyatora
LP_SSD3 LD (DE), A; cleaning of one
DEC E; line image
tion:
JR NZ, LP_SSD3; (31 bytes)
LD (DE), A; clear the most
first byte
line
LD E, # 1F; transition to
next
(Top)
DEC D; through a number of
eight lines
BIT 6, D; we are not yet on
fell in the ROM?
JR NZ, LP_SSD2; if not,
purify further
RET; exit from the
procedure
;----------------------------------------;
; Left shift by one pixel (16 <= 17)
;----------------------------------------;
PSRL_LF
LD HL, # 57FF; address last
He bytes
Graphics
LP_PSL1 OR A; reset
carry flag
CF
LD B, # 20, in the same line
- 32 bytes
LP_PSL2 RL (HL); CF <- [shifts
my bytes] <-CF
(Left)
DEC HL; transition to
previous
byte lines
DJNZ LP_PSL2; shift cycle
for one if
SRI
BIT 6, H; we are still in the equivalent
wound?
JR NZ, LP_PSL1; if so,
shift the following
lowing line
RET; exit from the
procedure
;----------------------------------------;
; Right shift by one pixel (17)
;----------------------------------------;
PSRL_RG
LD HL, # 4000; address of the first
Byte Graphics
LD C, # C0; move -
192 lines
LP_PSR1 OR A; CF = 0 for empty
one column
left
LD B, # 20, the number of bytes in
one line
LP_PSR2 RR (HL); shift of one
bytes to the right
INC HL; next
byte lines
Image
DJNZ LP_PSR2; shift the entire
line - 32
Byte
DEC C; reduce
counter lines
JR NZ, LP_PSR1; if pushed
all the lines, then
STOP
RET; exit from the
procedure
;----------------------------------------;
; Upward shift by one pixel (38 <= 91)
;----------------------------------------;
PSRL_UP
LD DE, # 4000; starting address
Graphics
(Verh. line)
LP_PSU1 LD H, D; copied
start address
LD L, E; line graphs
in HL
LD BC, # 0020, the size of one
line
Th shift
more
RET; exit from the
procedure
;----------------------------------------;
; Shift attributes to the right (21 <= 23)
;----------------------------------------;
ASRL_RG
LD DE, # 5AFF; address last
He bytes
Attributes
LP_ASRG LD H, D; copied
DE to HL -
LD L, E; Last
byte lines
Attributes
DEC HL; penultimate
byte lines
Attributes
LD BC, # 001F; <line length
attributes> - 1
LDDR; line shift
Attributes
right
LD A, (CONSTS); color filling
of after
shift
LD (DE), A; set
new attribute
DEC DE; transition to
whether
SRI top
BIT 3, D; if we all
even in the attributes
max,
JR NZ, LP_ASRG; then repeat
cycle for the lyrics.
line
RET; exit from the
procedure
;----------------------------------------;
; Shift attributes up (19 <= 21)
;----------------------------------------;
ASRL_UP
LD HL, # 5820; address of the second
Line attributes
Comrade
LD DE, # 5800; address of the first
Line attributes
Comrade
LD BC, # 02E0; move:
23 lines of
32 bytes
LDIR; shift 23
bottom line
Up
LD A, (CONSTS); color for
complement the lower
her line
LP_ASUP LD (DE), A; set
new attribute
INC E; if filled
Does the whole village
glacial line
JR NZ, LP_ASUP; (E = 0) then
interrupt
cycle
RET; exit from the
procedure
;----------------------------------------;
; Shift attributes down (20 <= 21)
;----------------------------------------;
ASRL_DN
LD HL, # 5ADF; address of the end
second-line
bottom
LD DE, # 5AFF; address of the end
the lowest
line
LD BC, # 02E0; move: 23
Line 32
Byte
LDDR; shift 23
top line
down
LD A, (CONSTS); color for
complement ver
hney line
LP_ASDN LD (DE), A; set
new attribute
DEC E; if reached
the very first
first byte
JR NZ, LP_ASDN; of Atri
casks (E = 0);
then STOP
LD (DE), A; and establishes
Vai this byte
RET; exit from the
procedure
;----------------------------------------;
; Shift left one character (20 <= 21)
;----------------------------------------;
SSRL_LF
LD DE, # 4000; top domains
Graphic Tee
LP_SSLF LD H, D; address of the first
LD L, E; byte line
INC HL; address of the second
byte lines
LD BC, # 001F; how many bytes
shift
LDIR; line shift
Left on 1
bytes
XOR A; resets ak
kumulyator and
have brought
LD (DE), A; the last
(Right) bytes
line
INC DE; transition to
whether
line (bottom)
LD A, D; if the attributes
CP # 58; "still have not seen
give, "
JR C, LP_SSLF; then repeat
cycle for the lyrics.
line
RET; exit from the
procedure
;----------------------------------------;
; Right shift by one character (19 <= 22)
;----------------------------------------;
SSRL_RG
LD DE, # 57FF; Last
bytes of
Graphics
LP_SSRG LD H, D; address last
He bytes
LD L, E; current line
DEC HL; address before
last
Byte
LD BC, # 001F; shift: 31
bytes
LDDR; line shift
graphic to the right
XOR A; clear the accumulative
mulyator and for
so
LD (DE), A; first (le
vy) bytes are
Booths line
DEC DE; transition to
whether
Institute of higher
BIT 6D; if we have
not "come across"
in ROM
JR NZ, LP_SSRG; we continue
spin cycle
RET; exit from the
procedure
;----------------------------------------;
; Shift up one character (55 <= 68)
;----------------------------------------;
SSRL_UP
LD DE, # 4000; top of the screen
Noah region
LP_SSU1 PUSH DE; store ad
interest on line
stack
LD BC, # 0020, in line - 32
Byte
LD A, E; The register DE
is hell
res
ADD A, C; top Do
Research Institute. In Regis
triangle
LD L, A; HL should
get the hell
res
LD A, D; line, lying
ing from below
step 8.
JR NC, GO_SSUP; To this end,
Register E
we add 32
ADD A, # 08; and records
L. If proiGO_SSUP LD H, A; zoshlo
transition complement, then
H = D +8
LDIR; transfer of one
line (32
bytes)
POP DE; recovered
Vai address
start line
LD A, H; check: a
whether it is time
We zakrug
CP # 58; lyatsya? (Ne
renesli all
1923 series)
JR NC, LP_SSU2; if so,
transition to
cleanup
INC D ;------------;
LD A, D;
DOWN_DE
AND # 07; standard
sequence
sequence
JR NZ, LP_SSU1; commands
transition to
line down
LD A, E; on-screen
region
ADD A, # 20, (to register
DE)
LD E, A;
JR C, LP_SSU1; input:
DE - Address
line
LD A, D; Output:
DE - Address
line below
SUB # 08; used
battery
LD D, A;
JR LP_SSU1 ;------------;
LP_SSU2 XOR A; cleaning Accu
mulyatora
LP_SSU3 LD (DE), A; with him on
power -
INC E; cleaning of one
line image
tion
JR NZ, LP_SSU3; total: 32
Byte
LD E, # E0; transition to
next
INC D; (lower) if
Research images
of
BIT 3, D; filled
all subsequent
tions series?
JR Z, LP_SSU2; if not,
continue
fill
RET; exit from the
procedure
;----------------------------------------;
; Shift down by one character (55 <= 73)
;----------------------------------------;
SSRL_DN
LD DE, # 57FF; address last
He bytes
Graphics
LP_SSD1 PUSH DE; retained hell
res end if
SRI
LD BC, # 0020; the length of one
line image
tion
LD A, E; in register HL
SUB C; get the hell
res
LD L, A; end of the line
LD A, D; overlying
JR NC, GO_SSDN; starting with
step
SUB # 08; of 8 pixels
(Lines):
GO_SSDN LD H, A; HL = how to
feast; DE =
where
LDDR; transfer of one
Line graphs
POP DE; recovered
Vai address
end of line
BIT 6, H; if we have already
not in the screen,
JR Z, LP_SSD2; then go
to clean
LD A, D ;------------;
DEC D; UP_DE
AND # 07; standard
sequence
sequence
JR NZ, LP_SSD1; commands
transition to
line up
LD A, E; in screen
area (for
SUB # 20; register DE)
LD E, A;
JR C, LP_SSD1; input: DE
- The address line
LD A, D; output: DE
- The address line
above
ADD A, # 08; used
battery
LD D, A;
JR LP_SSD1 ;------------;
LP_SSD2 XOR A; cleaning Accu
mulyatora
LP_SSD3 LD (DE), A; cleaning of one
DEC E; line image
tion:
JR NZ, LP_SSD3; (31 bytes)
LD (DE), A; clear the most
first byte
line
LD E, # 1F; transition to
next
(Top)
DEC D; through a number of
eight lines
BIT 6, D; we are not yet on
fell in the ROM?
JR NZ, LP_SSD2; if not,
purify further
RET; exit from the
procedure
;----------------------------------------;
; Left shift by one pixel (16 <= 17)
;----------------------------------------;
PSRL_LF
LD HL, # 57FF; address last
He bytes
Graphics
LP_PSL1 OR A; reset
carry flag
CF
LD B, # 20, in the same line
- 32 bytes
LP_PSL2 RL (HL); CF <- [shifts
my bytes] <-CF
(Left)
DEC HL; transition to
previous
byte lines
DJNZ LP_PSL2; shift cycle
for one if
SRI
BIT 6, H; we are still in the equivalent
wound?
JR NZ, LP_PSL1; if so,
shift the following
lowing line
RET; exit from the
procedure
;----------------------------------------;
; Right shift by one pixel (17)
;----------------------------------------;
PSRL_RG
LD HL, # 4000; address of the first
Byte Graphics
LD C, # C0; move -
192 lines
LP_PSR1 OR A; CF = 0 for empty
one column
left
LD B, # 20, the number of bytes in
one line
LP_PSR2 RR (HL); shift of one
bytes to the right
INC HL; next
byte lines
Image
DJNZ LP_PSR2; shift the entire
line - 32
Byte
DEC C; reduce
counter lines
JR NZ, LP_PSR1; if pushed
all the lines, then
STOP
RET; exit from the
procedure
;----------------------------------------;
; Upward shift by one pixel (38 <= 91)
;----------------------------------------;
PSRL_UP
LD DE, # 4000; starting address
Graphics
(Verh. line)
LP_PSU1 LD H, D; copied
start address
LD L, E; line graphs
in HL
LD BC, # 0020, the size of one
line
