Tandy 1000 Technical Reference Manual

Tandy 1000
Technical Reference Manual
Memory Map
Video Array 3DA & 3DE
Video
Array13
Address (3DA)
00 Bit 0
00 Bit 1
00 Bit 2
00 Bit 3
00 Bit 4
01 Bit 0
01 Bit 1
01 Bit 2
01 Bit 3
02 Bit 0
02 Bit 1
02 Bit 2
02 Bit
3
03 Bit 0
03 Bit
1
03 Bit 2
03 Bit 3
03 Bit 4
10 - 1F Bit 0
10 - 1F Bit 1
10 - 1F Bit 2
10 - 1F Bit 3
Read (3DA)
Display Inactive
Light Pen Set
Light Switch Status
Vertical Retrace
Not Used
Write (3DE)
Not Used
Not Used
Not Used
Not Used
Not Used
Palette Mask 0
Palette Mask 1
Palette Mask 2
Palette Mask 3
Border Blue
Border Green
Border Red
Border Intensity
Not Used
Not Used
Border Enable
4 Color High Resolution
16 Color Mode
Palette Blue
Palette Green
Palette Red
Palette Intensity
13. A Read at 3DA retrieves the status of the Video Array. To write to a register within the Video
Array, first write the register address
at 3DA and then write the register data at 3DE.
Detailed Memory Map--Continued
69

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