Memory Mapped I/O; Colour Vram - Sharp MZ-700 Service Manual

Memory Management (2)
PH111
WRN
MRQN
RDN
LPH1
NTPL
CL
GATE
VCC
GND
0
0
0
0
Colour VRAM (VRAM-2)
CAS circuit
1/4
• MZ-700 colour infonnation is managed character by
character. One byte of colour infonnation table is assign-
ed to each characters displayed on the TV screen.
D7
D6
D5
D4
D3
D2
D1
DO
ATB
FRONT G
FRONT R
FRONT B
Not used
BACK G
BACK R
BACK B
ATB: CGROM
address switch-
ingbit
. . . . +-_FRONT
BACK
Character iqfonnation is stored in address $DOOQ.
$D7FF and colour infonnation in $D80Q.$DFFF of the
VRAM.
11
~------------------------------<1SEL
COLR
NTSC
PAL
select
~-------------In PH
10
4-3. Memory mapped I/O ($EOOO - $EOO8)
CPU
memory Controller Function
address
$EOOO
PA : Output
$EOOl
Pe : Input
$E002
8255
Pc : Input/output mode controller
by bit cell
$E003 Mode controller
$E004 Co
: Mode
3
(square wave rate ge»erator)
$E005
C,
: Mode 2
8253
(rate generator)
$E006
C
2
: Mode
0
(terminal counter)
$E007
Mode controller
$E008
LS367 and
Tempo,joystick,
HBLNK
input
others