5. Memory mapping
5-1. Memory map as seen from the Z·80 (SC7852)
OOOOH
4000H
8000H
COOOH
FFFFH
-
PC-1600
PC·1600
ROM
(CSOO1)
I
PC·1600
PC·1600
CE·1600P
CE-1600P
Siot 2
ROM
ROM
ROM
S2
I
(Printer)
(Floppy
ROM
(C)
(CS24)
disk)
(CS001 )
I
Cassette
I
PC·1600
Siot 1
Siot 1
Siot 2
Siot 2
S1
Sl
S2
S2
(A)
(B)
(C)
(0)
ROM
(CS24)
(CS123)
PC·1600
(RAM3)
-_.-
Bank 0
Bank 1
Bank 2
Bank 3
Bank4
Bank 7
The memory space directly accessible by the Z·80 is 64KB,
however, the memory space is expanded to 320KB for the
PC·1600 by means of bank selection. Bank selection is done
according to the contents of the Z·80 I/F address 31 H.
When the Z·80
accesses aspace
in 000H~3FFFH,
bank
o
or bank
1 is selected depending
on the status
in bit
o
(bO) of the 1/0 address 31 H.
If bO
=
0, bank 0
-+
PVOUT: 0
If bO
=
1, bank 1
-+
PVOUT: 1
PVOUT (SC7852 output)
is used to represent the chosen
bank (0 or 1). PVOUT is 0 when bank 0 is selected. It is
1 when bank 1 is selected.
Similarly,
when
the
Z·80
accesses aspace
in 4000H
~
7FFFH,
bank 0 ~ bank 7 is selected depending
on the
status in the bits, b3 ~ bl. PVOUT, PU, and PT are used
to represent bank 0 thru bank 7.
The PVOUT, PU, and PT conform to the 1/0 address 31 H
and the space accessed
by
the Z·80.
It is possible to sense the status of the 1/0 address 31 H,
Bank 5
Bank 6
Table·2
Bank
z·ao
accessing
Status in the 1/0
PT
PU
PV
No.
space
address31H
OUT
b7 b6 b5 b4 b3 b2 bl bC
0
OOOOH-3FFFH
· · · · · · · · . .
0
1
t
·
*
· · · ·
*
1
.
*
1
0
4000H-7FFFH
*
*
*
*
0
0
0
*
0
0
0
1
t
*
· · ·
0
0
1
·
0
0
1
I
2
t
· · · ·
0
1
0
·
0
1
0
3
t
·
*
·
*
0
1
1
*
0
1
1
C
t
· · · ·
1
0
0
·
1
0
0
5
t
· · · ·
1
0
1
·
1
0
1
6
t
· · · ·
1
1
0
·
1
1
0
7
t
· · · ·
1
1
1
·
1
1
1
0
8000H-BFFFH
·
0
0
0
· · · ·
0
0
0
1
t
·
0
0
1
· · · ·
0
0
1
2
t
·
0
1
0
· · · ·
0
1
0
3
t
·
0
1
1
·
*
*
*
0
1
1
C
t
·
1
0
0
*
*
·
*
1
0
0
5
t
*
1
0
1
*
*
*
*
1
0
1
6
t
*
1
1
0
*
*
*
*
1
1
0
7
t
·
1
1
1
·
*
*
*
1
1
0
0
COOOH-FFFFH
0
*
·
*
*
·
*
·
*
.
0
1
t
1
*
*
*
*
*
·
*
*
*
1
':
DON'T
CARE
Summary of Contents for PC-1600
Page 42: ... 11 CIRCUIT DIAGRAM PARTS POSITION KEY P W B LCD SIDE 39 ...
Page 43: ...PC l600 40 ...
Page 44: ...PC 1000 KEY P W B LSI SIDE 41 ...
Page 45: ... 42 ...
Page 48: ... PC l600 F P C P W B 45 ...
Page 49: ... Kn 46 ...
Page 52: ... PC l600 CONNECTOR P W B 49 ...
Page 53: ... 50 ...
Page 55: ... __ PC l600 tli I ONLY Pc 1600K I I 1 I 52 l J ...
Page 56: ... PC l600 K MEMORY P W B ROM Cut c IJ O lJ1F C O lJ1F I Bend capacitor to inward ROM SIDE 53 ...
Page 57: ...RAM SIDE 54 ...
Page 61: ...I I 2 3 4 42 58 ...
Page 93: ... P W B LSI SIDE t 90 ...
Page 117: ... PC I600 ...