ETUDES
Music by ZET
(C) Ivan Roshchin, Moscow, 1996
Bring to your attention I wrote a program that implements a
nice visual effect: the screen moving color bars, which fades
each other. This full-screen REAL-TIME takes effect only about
60% of the time processor. Sequence
bands and smooth transition between them can be changed.
140 .;*********************************************** *****
CLR0 EQU 0; COLOR BANDS
CLR1 EQU 1; (downward)
CLR2 EQU 2
CLR3 EQU 3
CLR4 EQU 4
CLR5 EQU 5
CLR6 EQU 6
;************************************************* ***
DEMO LD C, 0; vertical displace
; STRIP lifting:
LOOP1 CALL SHOW; DRAW BAND
CALL KEY; ANYTHING pressed?
RET NZ; IF YES, EXIT
INC C; INCREASED DISPLACEMENT
LD A, C; reached the limit?
CP TABMAXA-23
JP NZ, LOOP1; IF NO, CONTINUE.
; STRIP DOWN:
DEC C; REDUCE
DEC C; OFFSET
LOOP2 CALL SHOW; DRAW BAND
CALL KEY; ANYTHING pressed?
RET NZ; IF YES, EXIT
DEC C; REDUCE THE OFFSET
LD A, C; reached the minimum?
CP # FF
JP NZ, LOOP2; IF NO, CONTINUE.
LD C, 1; OTHERWISE GO TO
JP LOOP1; beginning the program.
;***************************************
; PROCEDURE SHOW
; LOG: C-BAND VERTICAL DISPLACEMENT (IN
; Familiarity)
; OUTPUT: Mimicking PASS. PICTURE.
SHOW; FIRST, an imaging ATTRIBUTES:
LD DE, TABL_A; ADDRESS attribute table
LD H, 0; HL = OFFSET
LD L, C
ADD HL, DE; add an offset
LD DE, # 5800; beginning of the file ATTRIBUTES
HALT; WAITING FOR THE START OF FRAME
DI; disable interruptions, TK
; WILL manipulated from the stack.
NEXT_A LD A, (DE); which attribute picture?
CP (HL); what we need?
JP Z, RETU; IF YES, DO NOT PEESYLAEM
PUSH HL; SAVE ADDRESS OF SOURCE
LD A, (HL); BYTES FROM THE SOURCE
LD (M1 +1), SP; PRESERVE SP (NOTE WHERE).
LD HL, # 20, generates a new
ADD HL, DE; ADDRESS STACK
LD SP, HL
LD D, A; than fill
LD E, A; STRING
PUSH DE; forming one
PUSH DE; STRING
PUSH DE
PUSH DE
PUSH DE
PUSH DE
PUSH DE
PUSH DE
PUSH DE
PUSH DE
PUSH DE
PUSH DE
PUSH DE
PUSH DE
PUSH DE
PUSH DE
EX DE, HL; In DE NEW ADDRESS RECEIVER
M1 LD SP, 0; RESTORE SP.
; This command LOAD SP
; DONE twice as fast
; Than a team of LD SP, (NN).
POP HL; RESTORE HL
JP NE_RETU; WAY, TEAM JP
; Run faster
; WHAT TEAM JR.
; If a line is was necessary to fill,
, Increases DE (addr. RECEIVER) FOR # 20:
RETU LD A, # 20, looks like it is
ADD A, E; unusual, but
LD E, A; WORKS
LD A, 0; FASTER.
ADC A, D
LD D, A
, Otherwise the destination address has already been increased.
NE_RETU INC HL; Source Address
LD A, D
CP # 5B
JP NZ, NEXT_A
And now draw the image:
LD L, C; Offset in familiarity
SLA L; multiplied by 8
SLA L
SLA L
RES 7, L
LD B, L; GET OFFSET TABLE
LD H, 0; HL = OFFSET. TABLE
LD DE, TABL; ADDRESS TABLE
ADD HL, DE
EX DE, HL
LD HL, # 4000; HOME DISPLAY FILE
And here, on the contrary, HL-receiver address, A
; DE-source address.
NEXT LD A, (DE); an imaging BYTES
CP (HL); Compares with the image.
JP Z, RET3; If zero, do not send
PUSH HL; SAVE ADDRESS OF RECEIVER
, Increases HL (addr. RECEIVER) FOR # 20:
LD A, # 20, looks like it is
ADD A, L; unusual, but
LD L, A; WORKS
LD A, 0; FASTER.
ADC A, H
LD H, A
LD (M2 +1), SP; PRESERVE SP
LD SP, HL; SP indicates the end of STRING
LD A, (DE)
LD H, A; than fill
LD L, A; STRING
PUSH HL; forming one
PUSH HL; STRING
PUSH HL
PUSH HL
PUSH HL
PUSH HL
PUSH HL
PUSH HL
PUSH HL
PUSH HL
PUSH HL
PUSH HL
PUSH HL
PUSH HL
PUSH HL
PUSH HL
M2 LD SP, 0; RESTORE SP
POP HL; RESTORE ADDRESS OF RECEIVER
RET3 INC DE; HAS INCREASED SOURCE ADDRESS
INC B; INCREASED COUNTER
LD A, B
CP TABMAX; ACHIEVED MAX. ADDRESS?
JP NZ, TAB_OK
LD B, 0; IF YES, Zeroing COUNTER
LD DE, TABL; AND GO TO TOP OF TABLE
TAB_OK INC H; SINGLE
LD A, H; NEW ADDRESS
AND 7 LINES ON
LD A, H; SCREEN
JP NZ, NEW_OK; AT
LD A, L; LAST
ADD A, 32; STRING.
LD L, A
LD A, H
JP C, NEW_OK
LD A, H
SUB 8
LD H, A
NEW_OK CP # 58
JP NZ, NEXT
EI
RET
;***************************************
TABMAX EQU 16 * 8, the size of data sets (see below)
TABL DB% 00000000; the data to
DB% 00000000; smooth transition between
DB% 00000000; colored stripes.
DB% 00000000; WAY, FROM THEM
DB% 00000000; DEPENDS ON SPEED
DB% 00000000; PROCEDURE SHOW.
DB% 00000000
DB% 00000000
DB% 00000000
DB% 00000000
DB% 00000000
DB% 00000000
DB% 00000000
DB% 00000000
DB% 00000000
DB% 00000000
DB% 00001000
DB% 00000000
DB% 10000000
DB% 00000000
DB% 00001000
DB% 10000000
DB% 00001000
DB% 10000000
DB% 00100010
DB% 10001000
DB% 00100010
DB% 10001000
DB% 00100010
DB% 10001000
DB% 00100010
DB% 10001000
DB% 00100010
DB% 10001000
DB% 00100010
DB% 10001000
DB% 00100010
DB% 10001000
DB% 00100010
DB% 10001000
DB% 00100010
DB% 01010101
DB% 10001000
DB% 01010101
DB% 00100010
DB% 01010101
DB% 10001000
DB% 01010101
DB% 00100010
DB% 01010101
DB% 00100010
DB% 01010101
DB% 10001000
DB% 01010101
DB% 00100010
DB% 01010101
DB% 10001000
DB% 01010101
DB% 00100010
DB% 01010101
DB% 10101010
DB% 01010101
DB% 10101010
DB% 01010101
DB% 10101010
DB% 01010101
DB% 10101010
DB% 01010101
DB% 10101010
DB% 01010101
DB% 10101010
DB% 01010101
DB% 10101010
DB% 01010101
DB% 10101010
DB% 01010101
DB% 10101010
DB% 01010101
DB% 10101010
DB% 01010101
DB% 10101010
DB% 01010101
DB% 10101010
DB% 01010101
DB% 10101010
DB% 01110111
DB% 10101010
DB% 11011101
DB% 10101010
DB% 01110111
DB% 10101010
DB% 11011101
DB% 10101010
DB% 01110111
DB% 10101010
DB% 11011101
DB% 10101010
DB% 01110111
DB% 10101010
DB% 11011101
DB% 10101010
DB% 01110111
DB% 10101010
DB% 11011101
DB% 11011101
DB% 01110111
DB% 11011101
DB% 01110111
DB% 11011101
DB% 01110111
DB% 11011101
DB% 01110111
DB% 11011101
DB% 01110111
DB% 11011101
DB% 01110111
DB% 11011101
DB% 01110111
DB% 11011101
DB% 01110111
DB% 01111111
DB% 11110111
DB% 01111111
DB% 11110111
DB% 11111111
DB% 01111111
DB% 11111111
DB% 11110111
;************************************************* *******
TABMAXA EQU 6 * 16 +2, the size of data sets (see below)
TABL_A DB CLR0 * 8 + CLR1; FROM THEM DEPENDS
DB CLR0 * 8 + CLR1; COLOR OF EACH STRIP
DB CLR0 * 8 + CLR1
DB CLR0 * 8 + CLR1
DB CLR0 * 8 + CLR1
DB CLR0 * 8 + CLR1
DB CLR0 * 8 + CLR1
DB CLR0 * 8 + CLR1
DB CLR0 * 8 + CLR1
DB CLR0 * 8 + CLR1
DB CLR0 * 8 + CLR1
DB CLR0 * 8 + CLR1
140. DB CLR0 * 8 + CLR1
DB CLR0 * 8 + CLR1
DB CLR0 * 8 + CLR1
DB CLR0 * 8 + CLR1
DB CLR1 * 8 + CLR2
DB CLR1 * 8 + CLR2
DB CLR1 * 8 + CLR2
DB CLR1 * 8 + CLR2
DB CLR1 * 8 + CLR2
DB CLR1 * 8 + CLR2
DB CLR1 * 8 + CLR2
DB CLR1 * 8 + CLR2
DB CLR1 * 8 + CLR2
DB CLR1 * 8 + CLR2
DB CLR1 * 8 + CLR2
DB CLR1 * 8 + CLR2
DB CLR1 * 8 + CLR2
DB CLR1 * 8 + CLR2
DB CLR1 * 8 + CLR2
DB CLR1 * 8 + CLR2
DB CLR2 * 8 + CLR3
DB CLR2 * 8 + CLR3
DB CLR2 * 8 + CLR3
DB CLR2 * 8 + CLR3
DB CLR2 * 8 + CLR3
DB CLR2 * 8 + CLR3
DB CLR2 * 8 + CLR3
DB CLR2 * 8 + CLR3
DB CLR2 * 8 + CLR3
DB CLR2 * 8 + CLR3
DB CLR2 * 8 + CLR3
DB CLR2 * 8 + CLR3
DB CLR2 * 8 + CLR3
DB CLR2 * 8 + CLR3
DB CLR2 * 8 + CLR3
DB CLR2 * 8 + CLR3
DB CLR3 * 8 + CLR4
DB CLR3 * 8 + CLR4
DB CLR3 * 8 + CLR4
DB CLR3 * 8 + CLR4
DB CLR3 * 8 + CLR4
DB CLR3 * 8 + CLR4
DB CLR3 * 8 + CLR4
DB CLR3 * 8 + CLR4
DB CLR3 * 8 + CLR4
DB CLR3 * 8 + CLR4
DB CLR3 * 8 + CLR4
DB CLR3 * 8 + CLR4
DB CLR3 * 8 + CLR4
DB CLR3 * 8 + CLR4
DB CLR3 * 8 + CLR4
DB CLR3 * 8 + CLR4
DB CLR4 * 8 + CLR5
DB CLR4 * 8 + CLR5
DB CLR4 * 8 + CLR5
DB CLR4 * 8 + CLR5
DB CLR4 * 8 + CLR5
DB CLR4 * 8 + CLR5
DB CLR4 * 8 + CLR5
DB CLR4 * 8 + CLR5
DB CLR4 * 8 + CLR5
DB CLR4 * 8 + CLR5
DB CLR4 * 8 + CLR5
DB CLR4 * 8 + CLR5
DB CLR4 * 8 + CLR5
DB CLR4 * 8 + CLR5
DB CLR4 * 8 + CLR5
DB CLR4 * 8 + CLR5
DB CLR5 * 8 + CLR6
DB CLR5 * 8 + CLR6
DB CLR5 * 8 + CLR6
DB CLR5 * 8 + CLR6
DB CLR5 * 8 + CLR6
DB CLR5 * 8 + CLR6
DB CLR5 * 8 + CLR6
DB CLR5 * 8 + CLR6
DB CLR5 * 8 + CLR6
DB CLR5 * 8 + CLR6
DB CLR5 * 8 + CLR6
DB CLR5 * 8 + CLR6
DB CLR5 * 8 + CLR6
DB CLR5 * 8 + CLR6
DB CLR5 * 8 + CLR6
DB CLR5 * 8 + CLR6
DB CLR6 * 8 + CLR6
DB CLR6 * 8 + CLR6
;**************************************
; PROCEDURE KEY returns a flag Z = 0
; If your keyboard ANYTHING down.
KEY XOR A
IN A, (254)
AND% 00011111
CP% 00011111
RET
2
*
