Sharp MZ-80B - Page 53

46
The relation between V-RAM output and the CRT display is as shown in FIGURE 4.6.
Address
$DOOO
I
($5000)
$D7CF
($57CF)
V-RAM
Character
Address
$EOOO
($6000)
$FF3F
($7F3F)
CRT
Display
Address
$EOOO
V-RAM
($6000)
V-RAM
Graphic I
Graphic
II
$FF3F
l;_
($7F3F)
Switching by OUT port $F4
FIGURE 4.6 Relation between V-RAM and CRT display.
As shown in the figure, V-RAM characters and graphic (I) and (ll) can be displayed simultaneously.
The relation between V-RAM addresses and corresponding positions on
the CRT display is as
shown in FIGURE 4.7.
• V -RAM characters
$DOOO
$D027 $DODO
($5000)
($5027)
($5000)
25 lines
25 lines
$D3CO
$D3E7
$D780
($53 CO)
($53E7)
($5780)
40 characters
80 characters
• V-RAM graphic
.-------------------~
NOTE:
200 dots
$EOOO
($6000)
$FF18
($7Fl8)
320 dots
$E027
($6027)
$FF3F
($7F3F)
The addresses when V-RAM
is set in the $5000~$7FFF
mode are shown in paren-
theses.
FIGURE 4.7 V-RAM addresses and CRT display
$D04F
($504F)
$D7CF
($57CF)