User`s guide
Extended
Display
Subroutine
(
cont)
NEW
LINE
O32C :
2El,
CONT
LINEO331
:
34:
36:
0338
LOOP
3A
3D
40
SHIFTEI\TT
IIT
9D
F8
FB
9E
4A
30
97
B7
26
B6
AD
00
s2
00
A7
A6
87
4T
F6 87
76 A7
3A
3A
Put
NB
into
RD
.0
(
counter
for
bytes
)
Clear stack
Clear
R7 .0
Put XL
into
R6
.0
(
shift
counter)
Data
byte
put
into
R7
.1
GotO
SHIFTENT
\
Shi
f
t contents
of iR7
.
1
to right
Shift carry
over
bits into R7.0
R6- 1
If
R6.0
is not
zero
goto
LOOP
WRITE
o344
47
4B
4B
4E
51
F4 87
97
EC
F2
FB
97
E2
32
o1
F3
B7
4E
BF
5C
52
:
Add
carry
over
f
rom
last
byte to R7.1
:SetXtoC
:
Test
for
hit,
if
not
goto
WRITE
:
Hit
Flag
=0L
: Write byte
to
di
splay
with
: Store
new
ca rry
over
b
te
''XOR
on
st
u"U
;ound
)
doesn't/
change
v
(Increment
RC to next byte
on
line,
test
for
and correct X wrap
a
0354:8C FC
01
Ac
:
RC.0+01rdo it ttris
way so
Rc.l
58: FA
07 3A
60
:
@O7rif
not
O
goto
CONT
'
5C: 8C Fr
OA
AE
:
Move
Rc.O up one line
on
displa
CONT
60:2D
BD 3A
31
:
RD.0-01rif not
O
qroto
CONT
LINE
(write
last
carry over bits on
]-ine)
0364:
87
:
Get
carry
over byte
65:
EC
FZ
32
6C
:
Test
for
hit, if not
goto
WRITE2
69: F8
01
BF
:
Set
Hit
Ptaq
to O1
wRrTEz
6c: 87 F3 5c
: write to display with
"xoR'!'
6Fr E2 : Reset
X
to 2
(Move
RC
to next
l-ine,
test for
and
correct
Y
wrap
around)
O37O: 2E BE 32
87
:NL-L, if 0
goto
EXIT
74t BF
FC Og Fc eF
:
Get
first value
of
RC.O on
to next
linerstore
new RC.0
79r 9C 7C O0
BC
:
RC.l+carry
7D:
FF
10
3A 2C
:
-(0C+04),
if not 0
goto
NEW
81: 9C FF 04
BC
:
Reset RC to
top
of
display
85: 30
2C
:
Goto NEW LINE
line
r
rrrove
in
RF
.0
LTNE
EXIT
Upon returning from the subroutine
I=I+(2+NB*NL)+1.With
DXYN
f=I
0387: FB
FF
A6
BA: 9F 56
BC2
L2
BD: 00 D4
I
R6
points
to
VF
:
Store Flag in
VF,
:
Increment stack
i
Idle;
Return
There are
no limit.ations
NB
is larger
than 0B
or
will
write
over itself.
on the
values
for
NB
if
NL
is
longer than
or
NL. However,
if
the
display
the
object
The routine
will work wit.h
Ben
Hutchinson's
(
vrPER
vr
r
,
p9
7
)
with
the
f
ollowing
changes
,
with
a
NoP
(
E2
)
r have at 031
3
.
0 30e z
gei_
0
35E
19;
_937
6_1
0
;
The
four
pages
of
to
start
at 0C00.
1ZBH
by
64v
circuit
which
are
facifitated
memory asslgned
to
the
Al-splay
a7e
assumed
To change to
a new
page
address
(pCa),
replace
z.oB/09.U6