ETUDES
Music by ZET and MITCHELL
(C) Kolotov Sergei g.Shadrinsk,
SerzhSoft, July, 1997
Remake some of the procedures
1993
In the ZX-REVIEW-93 p. 121 was published procedure NM Stinova
called DOORS, realizing the effect of cleaning the screen by
moving apart pictures in hand. The procedure takes 101 bytes
and, frankly, is not written
very effectively. Used
alternative registers, but register as HL nowhere and is not
saved, which makes it impossible call this procedure from
BASIC. Applying command block Shipping and LDIR LDDR, managed
"Make friends" with new procedure
BASIC (good in her alternate registers are not generally used),
more than halving the volume of memory and significantly
improve performance. The new procedure also was completely
moved. When cleaning the image on the screen set to the current
system attributes of a cell 23693. That is, there is a
possibility change the color right out of Basic
teams INK, PAPER, BRIGHT,
FLASH or directly by submitting the command POKE 23693, n
before calling procedures RANDOMIZE USR adr.
Performing POKE adr +1, n (n = 1 .. 16),
You can set the number of
shifts to be performed in one run the procedure.
140.
; SCREEN-APART
3; (c) SerzhSoft, 11 july 1997
;
ORG 60000; address assembly
;
ATTR_P EQU 23693; current attributes of the main screen
;
APART
LD B, # 10, the number of pairs of shifts in the side
of the screen LP_APR1 PUSH BC; store count changes on the stack
LD A, (ATTR_P); A = attributes filled. after sdiga
LD DE, # 5AFF; the last byte of attributes
LP_APR2 LD H, D; copied this address
LD L, E; in HL and decreased to 1:
DEC HL; address byte of the penultimate line
LD BC, # 000F; shift: 15 bytes
LDDR; shift in the right half-line right
LD (DE), A; set the new value
LD BC, # FFF2; correction of p-pa HL - now
ADD HL, BC; indicates the second byte of the line
LD E, L; DE = HL
DEC E; first byte to the left of the line
LD BC, # 000F; will move 15 bytes
LDIR; shift left half-line to the left
LD (DE), A; establish a new byte (clear)
LD BC, # FFEF; correction register DE -
ADD HL, BC; go one
EX DE, HL; line up in the screen (attributes)
BIT 3, D; if the attributes are not over,
JR NZ, LP_APR2; something cool cycle
XOR A; passed in Graphics
BIT 6, D; if we have not yet got into the ROM
JR NZ, LP_APR2; then continue to twist the loop
POP BC; restore counter shifts
DJNZ LP_APR1; twist cycle put the number of times
RET; exit procedures
2
Hex dump procedure APART:
EA60: June 10 C5 3A 8D 5C 11 FF: 58
EA68: 5A 62 6B 2B 01 0F 00 ED: A1
EA70: B8 January 12 F2 FF 09 5D 1D: 99
EA78: 01 0F 00 ED B0 December 2001 EF: 11
EA80: FF 09 EB CB 5A 20 E2 AF: 1933
EA88: CB 72 20 DD C1 10 D3 C9: 19
Saving: SAVE "arart.c" CODE
60000,48
On page 35 ZX-REVIEW-93 was
published program of the shadow
Path. I was able to significantly improve the procedure for
Just rewrite it from scratch. The new procedure takes
138 bytes (old - 211 bytes) and
became relotsiruemoy. As before, to get a
pseudo-three-dimensional image, rather identify attributes of
high brightness places on the screen, which require shade and
call the procedure SHADOW. It is possible to change the
configuration of the most shade. For this necessary to change
the values in the Two teams load register pair DE, which are
labeled asterisks. In the present
program are set
# 5500, # 5500, respectively,
gives shade with slightly rounded edges. Substituting # 2A80,
# AA80, we shade the direct
edges. To get the same
result as in the original
option, you must install
# AA00, # 2A80. But the values
# 7F80, # FF80 will show you a continuous, unprimed shadow.
140.
; SHADOW-PROCESSOR
3; (c) SerzhSoft, 11 july 1997
;
ORG 60000; address assembly
SHADOW
LD HL, # 5AFF; the last byte of attributes
LP_SHD1 LD BC, # 0020, the number of bytes in one line
attributes
DEC HL; go to the previous attribute
BIT 3, H; we have not "stopped" in the schedule?
RET Z; if you have already, then exit procedure
BIT 6, (HL); this attribute with high brightness?
LP_SHD0 JR Z, LP_SHD1; if not, then the previous attribute
PUSH HL; attribute stores the address on the stack
INC L; move to the next attribute
LD A, L; test for transition
AND # 1F; to the next line attributes
JR Z, GO_SHD2; if yes, then jump
BIT 6, (HL); included whether the brightness?
JR NZ, GO_SHD2; if yes, then jump
PUSH HL; attribute stores the address on the stack
ADD HL, BC; the transition to an attribute on a line
below
LD C, (HL); put this attribute in the register C
POP HL; restore the address attribute
LD A, H; calculation of addresses
AND # 03; top line
RLCA; familiarity
RLCA; in the screen
RLCA; for a given
OR # 40; address in
LD H, A; field attributes
LD DE, # 5500 * way to create a shadow on the right *
LD B, # 0C; shadow height: 12 pixels
LP_SHD2 LD A, E; shifted byte image of the shadow line
AND # F0; discard the extra "right" bits
OR (HL); impose the contents of the screen
LD (HL), A; and write the new byte to the screen
INC H ;---------------------------------
LD A, H;
AND # 07; standard
JR NZ, GO_SHD0; sequence
LD A, L; commands to move
ADD A, # 20, on a line below
LD L, A; in the display area
JR C, GO_SHD1;
LD A, H;
SUB # 08;
LD H, A ;--------------------------------- GO_SHD1 LD
A, H; byte address into the graph
CP # 58; verification. to go beyond the boundaries of
the screen
JR NC, GO_SHD2; if yes, then jump
BIT 6, C; check brightness: can we image
JR NZ, GO_SHD2; reap shadow. if not, then jump
GO_SHD0 SRL D; rotation of the image
RR E; shadow line to the right
DJNZ LP_SHD2; cycle the number of lines in the shadows
GO_SHD2 POP HL; restore the address attribute
PUSH HL; attribute stores the address on the stack
LD BC, # 0020, the number of bytes in one line
attributes
ADD HL, BC; the transition to an attribute under the
current
LD A, H; check the new address attribute
CP # 5B; for joining the edge of the screen
JR NC, GO_SHD4; if outside, then the transition
BIT 6, (HL); if he enters the screen, but the brightness
JR NZ, GO_SHD4; enabled, anyway - go
INC L; next byte of attributes (right)
LD C, (HL); put in the register C
LD A, H; calculation of addresses
AND # 03; top line
RLCA; familiarity
RLCA; in the screen
RLCA; for a given
OR # 40; address in
LD H, A; field attributes
LD DE, # 5500 * way to create shadows below *
LD B, # 04; height of the shade lower
LP_SHD3 DEC L; back to byte back
LD A, (HL); took bytes from the screen
OR D; imposed bytes left of the image line
LD (HL), A; the shadows and put back into the screen
INC L; the transition to a byte to the right
LD A, L; check out
AND # 1F; for the right border of the screen:
JR Z, GO_SHD3; if yes, then jump
BIT 6, C; if the attribute with the brightness,
JR NZ, GO_SHD3; it the same way - jump
LD A, (HL); took bytes from the screen
OR E; laid right bytes of the image line
LD (HL), A; the shadows and put back into the screen
GO_SHD3 INC H; the transition to the next line
SRL D; rotation of the image of one
RR E; shadow line to the right
DJNZ LP_SHD3; cycle the number of lines in the image of
the shadows GO_SHD4 POP HL; restore the address attribute
XOR A; mouth. Flag Z, to JR Z worked
JR LP_SHD0; go to a team JR Z, LP_SHD1
2
Hex dump procedure SHADOW:
EA60: 21 FF 5A 20 January 2000 2B CB: DB
EA68: 5C C8 CB 76 28 F5 E5 2C: E5
EA70: 7D E6 1F 28 3A CB 76 20: 9F
EA78: 36 E5 09 4E E1 7C E6 03: 1A
EA80: 7 July 2007 F6 40 67 November 2000: 2D
EA88: 55 06 0C 7B E6 F0 B6 77: 57
EA90: 24 7C E6 20 July 1913 7D C6: 7D
EA98: 20 6F 38 04 7C D6 August 1967: 0E
EAA0: 7C FE 58 30 0A CB 71 20: F2
EAA8: 06 CB 3A CB 1B 10 DC E1: 50
EAB0: E5 20 January 2000 09 7C FE 5B: 7E
EAB8: 30 2C CB 76 20 28 2C 4E: 01
EAC0: 7C E6 03 7 July 2007 40 F6: 5A
EAC8: 67 11 00 55 06 04 2D 7E: 34
EAD0: B2 77 2C 7D E6 1F July 28: C0
EAD8: CB 1971 March 20 7E B3 77 24: ED
EAE0: CB 3A CB 1B 10 E8 E1 AF: 3D
EAE8: 18 82 00 00 00 00 00 00: 6C
Saving: SAVE "shadow.c" CODE
60000,13
In the ZX-REVIEW-93 at p.117 was
published procedure LOOK BASIC
PROGRAMMS, the author - Alexander Bessonov. It takes 344 bytes
that in my opinion - is simply blasphemous! I managed to cut
the program more than twice (or more precisely, to rewrite it
from scratch). The principle of operation is almost changed,
however, there was a new opportunity. When you print a notation
of any control code followed by the output value of its
parameter. For example, after the panel. Code 16
(INK CTRL) is a byte value
color that the screen will look something like this: I [7] (all
inverted). And after the codes 22 and 23
(AT CTRL, TAB CTRL) must be followed by two values: A [2] [10]
or T [18] [0]. Otherwise, the program works the same way as
original. The procedure takes 158
bytes.
140.
;
; LOOK BASIC PROGRAMS II
3; (c) SerzhSoft, 11 july 1997
;
ORG 65000; address assembly
;
PROG EQU # 5C53; syst. per. "Address start BASIC-program
VARS EQU # 5C4B; system. per. "Address start BASIC-variables"
;
OUT_NUM_2 EQU # 1A28; system. pr-pa "print the line number (HL)"
CHAN_OPEN EQU # 1601; system. pr-pa "discovery channel output"
STACK_NUM EQU # 33B4; system. pr-pa "to put (HL) on the stack
to-ra" STACK_A EQU # 2D28; system. Ave pa 'to put A on the
stack Calculator RA STACK_BC EQU # 2D2B; system. pr-pa "to put
BC on the stack to-ra" PRINT_FP EQU # 2DE3; system. pr-pa
"print the contents of the stack k." ;
LBP_2
LD A, # 02; open the output channel
CALL CHAN_OPEN; on the main screen
LD HL, (PROG); address of the start BASIC-program
LP_LBP1 LD DE, (VARS); address of the start BASIC-variables
AND A; reset carry flag for SBC
SBC HL, DE; check for completion of the program
RET NC; if HL> = DE, then the output of the procedure
ADD HL, DE; recover the value of HL
PUSH HL; store the string address on the stack
CALL OUT_NUM_2; print line numbers
POP HL; Restore rd row address from the stack
PUSH HL; and - again - keep
LD B, H; copied
LD C, L; HL in BC
140. CALL PRN_BC; printed the address of the string in memory
POP HL; Restore rd row address from the stack
INC HL; transition to
INC HL; length of the string
LD C, (HL); low byte string length
INC HL; further
LD B, (HL); byte string length
INC HL; the transition to the contents of a string
PUSH HL; store address on the stack
CALL PRN_BC; print length of the current BASIC-line
POP HL; reconstruct the address from the stack
LP_LBP2 LD A, (HL); the current character string
INC HL; move to the next
CP # 0D; check for end of line
JR Z, GO_LBP1; if yes, then go to the processing
LD DE, LP_LBP2; address cycle on the characters throw on
PUSH DE; stack to "return" on RET
CP # 0E; stumbled upon a number?
JR Z, GO_LBP2; if yes, then go to the processing
CP # 08; code shift back by one position?
JR Z, GO_LBP3; if so, the process
CP # 10, if the character code is less than 16,
JR C, GO_LBP0; then print it and - "to CA. characters.
CP # 18, if 16 <= character code <= 23
JR C, GO_LBP4; then go to panel processing. code
GO_LBP0 RST # 10; print one character
RET; transition to LP_LBP2
;
GO_LBP1 RST # 10; print code # 0D - newline
LD A, # 0D; and again
RST # 10; newline
JR LP_LBP1; move to the next BASIC-line
;
GO_LBP2 PUSH HL; store address on the stack
CALL STACK_NUM; 5-byte number -> on the stack tracing
paper.
CALL PRN_NUM; print it
POP HL; reconstruct the address from the stack
LD BC, # 0005, and the transition to a character string
for the BASIC-
ADD HL, BC; this 5-byte number
RET; transition to LP_LBP2
;
GO_LBP3 ADD A, # 07; correction code for # 08
GO_LBP4 SUB # 0F 3; received the number # 00 ... # 07 and have
brought
LD C, A; it in BC - it is the index (position)
LD B, # 00; notation Ex. code in the table
PUSH HL; store address on the stack
LD HL, TBLCODE; address table notation Ex. k.
ADD HL, BC; addressed the element of this table
SET 2, (IY +87); include inversion for printing
LD A, (HL); took the code no. Ex. code from the table
RST # 10, published his (written)
RES 2, (IY +87); disable inversion for printing
POP HL; reconstruct the address from the stack
LD A, C; determine the size of Manage. Code:
OR A; if it was the code # 08,
RET Z; then leave (it has no parameters)
CP # 06; if it were code # 16, # 17,
CALL NC, GO_LBP5; need to print two perametra
GO_LBP5 LD A, (HL); have one byte of memory (pair-p)
PUSH HL; store address on the stack
CALL STACK_A; scores a value of A on the stack since
CALL PRN_NUM; print this value (parameter)
POP HL; reconstruct the address from the stack
INC HL; move to the next. character in a string
RET; "return" on GO_LBP5 or LP_LBP2
;
PRN_BC CALL STACK_BC; put BC on stack calculator
;
PRN_NUM SET 2, (IY +87); include inversion for printing
LD A, "["; print it
RST # 10, a left bracket (opening)
CALL PRINT_FP; then - the number from the stack
Calculator pa,
LD A, "]"; and finally print
RST # 10, right bracket (closing)
RES 2, (IY +87); disable inversion for printing
RET; return from subroutine
;
TBLCODE DB "
