Tandy 1000 Technical Reference Manual

Tandy 1000
MC6845
Cursor Start Register
Technical Reference Manual
FIGURE 10 - CURSOR CONTROL
Bit
6
Bil
5
Cursor Displav Mode
Non-Blink
Cursor Non-Displav
Blink, 1/16 Field Rate
Blink, 1/32 Field Rate
I
-.l
......
I
On I Off I On I
I
r-- ~~i~~ ~;r~i~:S
Field Period
.. +
Example of Cursor Display Mode
o -++-+++++-
1 -+-+-+-+-+-++-
2 -++-+-+-+-++-
3 -++-+-+-+-++-
4 -++-+-+-+-++-
5 -++-+-+-+-++-
6 -++-If-+-+-+-+-
1 -+-t-lH-+-t-t-
8 -++-If-+-+-+-+-
1~""~~"~
11 -+-t-lH-+-t-t-
Cursor Start Adr. = 9
Cursor End Adr. :::: 9
o -+-H-t-+-+-t-
1 -+-H-+-+-+-+-
2 -+-H-+-+-+-+-
3 -+-H-+-+-+-+-
4 -+-H-+-+-+-+-
5 -+-H-+-+-+-+-
6 -+-H-+-+-+-+-
1 -+-H-+-+-+-+-
8 -+-H-+-+-+-+-
1~::~~~:::
11 -+-H-t-+-+-t-
Cursor Start Adr. = 9
Cursor End Adr. =- 10
o -++-+-++-++-
~.
6 -+-Hf-+-+-+-+-
1 -++-+-+-+-++-
8 -+-Hf-+-+-+-+-
9 -+-Hf-+-+-+-+-
10 -+-Hf-+-+-+-+-
11 -+-Hf-+-+-+-+-
Cursor Start Adr. = 1
Cursor End Adr. 0;: 5
FIGURE 11 - INTERFACE CONTROL
Interlace M.od. Register
Bit Bit
1 0
o 0
1 0
o 1
1 1
Mode
Normal Sync Mode (Non·lnterlacel
Interlace Sync Mode
Interlace Sync & Video Mode
-1
Odd Even
Field Field
Scan Line Address
o 0
o 0
o 0
00000
o 0
o 0
o 0
Even
Field
Scan Line Address
~~~
0--------
2 _
-------3
4
-
_1
Odd
Field
Normal Sync
Interlace Sync I nterlace Sync and Video
@ MOTOROLA Semiconductor Product. Inc.

Tandy 1000 Specifications

General

Processor	Intel 8088
Processor Speed	4.77 MHz
RAM	128 KB (expandable to 640 KB)
Operating System	MS-DOS 2.11
Manufacturer	Tandy Corporation
Release Year	1984
Storage	Single or double 5.25" floppy disk drive (360 KB), optional hard drive
Sound	Tandy 3-voice sound
Ports	Parallel, Serial
Graphics	CGA (Color Graphics Adapter)
Graphics Modes	320x200, 640x200