Memory Map - Sharp mz-800 Technical Reference And User's Manual

3 Memory map
The MZ-800 has a different memory map depending on
Q
MZ-800 memory map
EOOO
0000
MAIN
D-RAM
8000 ----- - 64-K&-- -
4000
2000
1000
oooo.
MZ-700mode
D
bd
.---,
~
~
ROM
VRAM
MZ-800 mode
MAIN
D-RAM
the mode. To have compatibility with the MZ-700, it has
two modes of the MZ-700 mode and MZ-800 mode.
~
t:J
-[] \J
D
DV-RA~--,
I I I I
I I I
1
I I l D I !m} I
I : : :
------ -L ••
.J ._ __ J
r---,
I I
I I
: IIVI I
' I
o I
L--..1
~
640
x
200
mode
~
VRAM
320 x 200 mode
NOTE:
r---.
I I
:m:
I I
... __ .J
Item within darted line
represent!l an option unit
MZ-1R2S
Memory map changes after initial program loading
$0000
$1000
$2000
@ Power on (reset)
MZ-800 mode
MON. ROM
CG. ROM
DRAM
@At start of monitor
MZ-700 mode
$0000 . . . - - - - - - - - .
MON. ROM
$1000
~------1
LD A, OSH
©Write to PCG from CG
MZ-700 mode
$0000
$1000
$2000
MON. ROM
CG. ROM
@ System operation
MZ-700 & 800 modes
$0000
OUT (CE), A
IN (EOH), A
$8000
=>
DRAM
V-RAM
(320x200 mode)
DRAM
$0000
V-RAM
$EOOO $EOOO
$E010
MON. ROM
MON. ROM
$FFFF $FFFF
• Memory map at power on is in the MZ-800 mode as
in @, but it changes to the MZ-700 mode by the
monitor ROM when the monitor program starts. After
transferring the CG data to the VRAM PCG area from
the CG ROM at @, the memory map then returns to
@.
• When the system program is completed to load, the
memory map goes into the MZ-700 mode if the
system switch (SW1) is set to ON side. If set to OFF
side, it changes to the MZ-800 mode, then the
memory map as in @. During those changes, all
memory spaces are composed of RAM and isolated
from ROM and VRAM.
3
D-RAM
D-RAM
==>
IN (E1H), A
<=
$COOO
V-RAM (CG)
$0000
V-RAM
$EOOO
$E010
MON. ROM
$FFFF SFFFF ' - - - - - - - - - '
• Depression of the manual reset switch
~ssumes
memory map transition in order of @
---+
@
---+
@
---+
@, similar as in the case of power on.
• ·However, depression of the reset switch in conjunc-
tion with the
I
CTRL
I
key assumes the memory map of
@after being changed once to the MZ-700 or MZ-800
mode depending on the state of the system switch. In
the case of the MZ-800 mode, it is set to the plane I,
II (4-color mode) of the 320 x 200 mode.