IBM 5150 Hardware Reference Manual

Bit 5 When on, this bit will change the character background
intensity to the blinking attribute function for
ALPHA
modes. When the high order attribute bit is not selected, 16
background colors (or intensified colors) are available. For
normal operation, this bit should be set to "1" to allow the
blinking function.
Mode Register Summary
Bits
0
1 2 3 4 5
0 0
1 1
0 1
40 x 25 ALPHA B & W
0 0 0
1 0
1
40 x 25 ALPHA COLOR
1 0 1 1 0 1
80 x 25 ALPHA B & W
1
0 0
1
0 1
80 x 25 ALPHA COLOR
0
1 1 1
0
z
320 x 200 B & W GRAPHICS
0
1
0
1
0
z
320 x 200 COLOR GRAPHICS
0
1 1
1 1 z
640 x 200 B & W GRAPHICS
'1'
4"
l"
~
.~
'1'
ENABLE BLINK ATTRIBUTE
640 x 200 B& W
ENABLE VIDEO
SELECT B & W MODE
SELECT 320 x 200 GRAPHICS
80 x 25 ALPHA SELECT
Z = don't care condition
* THE LOW RESOLUTION 160 x 100 MODE REQUIRES SPECIAL PROGRAMMING
AND IS SET UP AS ALPHA MODE 40 x 25
Status Register
~ The status register is a 4 bit read only register. Its address is X'3DA'.
It can be read using the 8088 I/O IN instruction.
2-59

IBM 5150 Specifications

General

Processor	Intel 8088
Clock Speed	4.77 MHz
RAM	16 KB - 256 KB
Manufacturer	IBM
Model	5150
Release Year	1981
Storage	5.25-inch floppy drives
Graphics	MDA or CGA
Operating System	IBM PC DOS
Ports	Cassette, keyboard
Expansion Slots	5