Atari 400 Technical Reference Manual page 153

PND=
*
'PND' = NEXT FREE LOCATION.
. END
Figure 10-4 Sample Cassette-Bootable Program
Program to Create Cassette-Boot Files
This section provides a program listing that can be used to make
boatable files on cassette tapes. The program given is not the only
one possible, and no claims are made as to its elegance.
Shown below is
a
listing of the program to create a cassette-boot
.pi
Ie:
THIS PROGRAM WRITES A SINGLE FILE TO THE CASSETTE AND IS
USED IN CONJUNCTION WITH A PROCEDURE TO MAKE CASSETTE-
BOOTABLE FILES. THE FOLLOWING TWO SYMBOLS MUST BE EGUATED
USING THE MEMORY LIMITS OF THE PROGRAM TO BE COPIED:
PST=
PND=
FLEN=
'PST' = PROGRAM START ADDRESS (SEE SAMPLE PROGRAM).
'PND' = PROGRAM END ADDRESS (SEE SAMPLE PROGRAM).
$0700
$1324
PND-PST+127/128*128
$8000
ROUND UP TO MULTIPLE OF 128.
THIS PROGRAM'S ORIGIN.
BOOTB LDX #$10
USE IOCB #1.
FIRST OPEN THE CASSETTE FILE FOR WRITING.
LDA
STA
LDA
STA
LDA
STA
LDA
STA
LDA
STA
JSR
BMI
IOPEN
ICCOM,X
lOP NOT
ICAX1,X
#$80
ICAX2,X
#CFILE
ICBAL,X
ICFILE/256
ICBAH,X
CIOV
CERR
SET UP FOR DEVICE "OPEN.
II
DIRECTION IS "OUTPUT."
SELECT SHORT IRG.
SET UP POINTER TO DEVICE NAME.
; ATTEMPT TO OPEN FILE.
i
ERROR.
NOW WRITE THE ENTIRE FILE AS ONE OPERATION.
OPERATING SYSTEM C016555 -- Section 10
168