AY-Track: LOW CODER'S LYRIC (ON FUNTOP'98)
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(C) Andrew Strelnikov
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The printing process
The programs at Basic'e commonly used procedures for
printing a native. To do this, they connect to the new channel
and print plain PRINT, or placed in
RAM pre-prepared messages and transmit them to the procedure of
printing the address using the POKE. Propose another way. Data
is transmitted via a user function. Text is placed in the REM
lines. Address Text is calculated by number of the first first
line with the text. Symbol of the end of the text is missing.
End of the text determined by the absence of the operator REM
at the beginning of the next Basic line. As an example, cite
the simple procedure of printing, which uses
PZUshnuyu RST 16.
; How to print the group of text strings
; Of BASIC.
And (c) Strelnikov AS
; Def fn a (n, x, y, t, p, b) = adr
; N - number of first-line with text
; X, y - coordinates
; T, p, b, - attributes (ink, paper, bright)
; Newline 13 (VC)
The text is placed behind the operator in REM
; Multiple lines.
; Print lines until it encounters
; Line that starts with another
; (Not REM) operator.
ORG 40000
LD A, 2
CALL 5633; open channel 2
, The definition addresses the first line of text
LD HL, (23563); defadd
INC HL
INC HL
CALL 13236
CALL 7833
PUSH BC
POP HL
CALL 6510
LD DE, 5
ADD HL, DE; now in HL address text
And after REM
Setting of print attributes
LD IX, (23563); Defadd
LD A, 16
RST 1916
LD A, (IX +28); ink
RST 1916
LD A, 17
RST 1916
LD A, (IX +36); paper
RST 1916
LD A, 19
RST 1916
LD A, (IX +44); bright
RST 1916
Setting of printing position
LD B, (IX +12); x
LD C, (IX +2); y
START LD A, 22; at
RST 1916
LD A, C; y
RST 1916
LD A, B; x
RST 1916
; Print
PRN LD A, (HL); have a symbol
CP 13; checking code VC
JR 2, PS; if so, the procedure ne
, Maps the line
RST 16; print symbol
INC HL; increment pointer
; Text
JR PRN; seal. symbol
; Newline: increase y by 1
S address is increased by 5 (go to the next, blowing line,
where after REM is The text: 2 byte line number 2 bytes long,
and on-line, and 1 byte - code 13 previous ; Line).
PS INC C; y = y +1
LD DE, 5
ADD HL, DE; adr = adr +5
LD A, (HL); if there
CP 234; code REM - skip
INC HL; it and print
JR Z, START; the next line if
Nay - reset
END CALL 3405; temporal attributes
RET; output
This program, in many cases more convenient than just PRINT.
It prints a few lines in the given coordinates. Can used to
print the menu descriptions and etc.
