EXAMPLES:
Assuming you've written a machine language program onto Track
1,
Sector 8
of
a
diskette, and would like
to
run it in buffer number 1
in
disk memory (starting at $0400
hexadecimal, you could
do
so
as follows:
110 OPEN 15,8,15
120 OPEN
2,8,2,"#1"
130 PRINT#15,"B-E:";2;0;1;8
140 CLOSE 2
150 CLOSE
15
160 END
USER COMMANDS
Open command channel.
Open direct access channel
to
buffer
1.
Load Track
1,
Sector 8
in
it
& execute.
Tidy up after.
Most User commands are intended to be used
as
machine language JMP or BASIC
SYS commands to machine language programs that reside inside the disk memory.
However, some
of
them have other uses as well. The U serl and U ser2 commands are used
to replace the BLOCK-READ and BLOCK-WRITE commands,
VI
re-starts the
1571
without changing its variables,
UJ
cold-starts the
1571
almost
as
if it had been turned off
and on again.
User
Command
uO
ul
or ua
u2
or
ub
u3
or
uc
u4 or ud
u5
or ue
u6 or
uf
u7
or
ug
u8
or uh
u9
or
ui
u:
or
uj
Function
restores default user jump table
block read replacement
block write replacement
jump
to
$0500
jump
to
$0503
jump
to
$0506
jump
to
$0509
jump
to
$050c
jump
to
$050f
jump
to
($fffa) reset tables
power
up
vector
By loading these memory locations with another machine language JMP command,
such as JMP $0520, you can create longer routines that operate
in
the disk's memory
along with an easy-to-use jump table.
FORMAT FOR USER COMMANDS:
PRINT # 15,' 'Ucharacter";
where
"character"
defines one
of
the preset user commands listed above.
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