Sharp MZ-3500 service manual Video RAM Structure of Vram

MZ3500

2) 20 line display mode

2)20 line display mode

8

20

Without line

10

\\NS\\\\Mi

ASCII

20

With line

HL On 18th raster

VL Line to the right of element

e VL does not join

a In the case of graphic symbol display, VL is overlaid to the pattern

Graphic symbol

j I Graphic symbol

9)Cursor

Sharp of the cursor: Same as seen in Model 3200 Reverse and blink)

10)Light pen input

Incorporates the light pen input connector and its inter- face. The light pen, however, is an option.

Accuracy: By each character

Function: Coordinates/charactercode

11)Difference in specification with that of Model 3200

(1)There are two modes for the Model 3200; normal mode ( 6 x 9 elements) and graphic mode ( 6 x 8 ele- ments). In the normal mode of 25-line displaying of the PC-3200, vertically adjacent graphic symbols do not joint. But, they will joint with the Model 3500.

Model-3200 Model 3500

4-2. Video RAM

1) Structure of VRAM

GDC1 (for character)

	Attribute
	I
*07FF
2 K b i t > 8	2 K b i t
( S-RA.M)	x4

GDC2 (for graphic)

#BFFF

1 6 K b i t	i
xg	i
(G)	t
	1
	1
	j
	i
	1
	1
	1
	1
	i
	i

(D-RAM)

16Kh,t 1 6 K b i t

(2)No line will be displayed for the medium resolution CRT (640x200 dot).

It is possible to display line on the high resolution CRT, compatible to line the utilizing program of the Model 3200

ts-

(ASCI L		RAM)			( B )	( R )
				' 0 0 0 0
# 0 0 0 0
DO-	-D7 1)8—Oil			DO-	-D7 D8-	-D15
			Solid line 48KB option
			Broken line. To be added to comprise
				the 96KB option.
VRAM capacity				Graphic option 1: 48KB
Basic 3KB (including attibutes)				Graphic option 2 96KB
Bit structure of VRAM
— —______ CRT j			640 x 400 dot		640 x 200 do i
Character	VRAM		8 bu / word		8 bit / word
Graphic	! 4 8 K B	'	16 bit	,' word	8 bit / word
V R A M	[ 9 6 K B		16 bit / word		16 bit / wo-d

- 30-