Hardware; Custom Lsi; Memory Controller; 1/0 Controller - Sharp mz-800 Technical Reference And User's Manual

4 Custom LSI
The custom LSI is a 100-pin single chip LSI on which the
MZ-800 memory controller (110 controller) and CRT
controller, etc. are contained.
4-1 Memory controller
Used for the control of the memory bank. Addressing of
DRAM, ROM, and VRAM is conducted by selection 110
address, $EO - $E6, using OUT or IN command.
1/0 Signal
Device (1/0)
address name
,
4-2 1/0 controller
In this 1/0 controller is created the select signal for
assignment of MZ-800 internal device.
See Table-2 for relation of internal device vs 110
address.
Function
FF Port B, printer data output
FE
CPR
Z80A Port A, printer control and timer interrupt
FD
PlO (110)
Port B control (Mode 0)
FC Port A control (Mode 3)
F2 PSG
PSG (0)
PSG output port
F1
JOY
JOYSTICK (I)
Joystick-2 input port
FO Joystick-1 input port
FO
--
(0)
Pallet write
E6
l
--
- -
(110)
Memory bank control
EO
07 Control port output
06
C53
8253 (110)
Counter-2 (NOTE): Mapped to E007 - E004 in the
os
Counter-1 MZ-700 mode.
04 Counter-0
DJ Control
02
KEY
8255 (110)
Port C, cassette, etc. (NOTE): Mapped to E003 - EOOO in the
01 Port 8, key input MZ-700 mode.
DO Port A, key strobe output
CF 0
CE 110
CRTC register
CD
--
--
0
cc
0
$E008
--
--
110 TEMP, HBLK input; and 8253 GO ON/OFF output for the MZ-700 mode only.
., When above 1/0 address is accessed, it makes IOWR active for OUT or lORD for IN command.
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