IBM 5150 Hardware Reference Manual page 374

Command Status Registers
Register 0 2-100
Control Codes
CPU (Central Processing Unit) see System Board,
CRT:
Register 1 2-101
Register 2 2-102
Register 3 2-103
CPS (Characters Per Second) 2-70
Microprocessor 2-3
CR (Carriage Return) 2-79
(Cathode Ray Tube) 2-37
Output Port 1 (I/O Address '3B8') 2-42
Status Port (I/O Address '3BA') 2-43
CTS (Clear To Send) 2-130
CSOUT (Chip Select Out) 2-132
Current 2-34
Cursor 2-14
D
DO-D7 JData Bits 0-7) 2-10
DACK - DAcK3 (DMA Acknowledge 0 to 3) 2-12
DATA
Bit (DO-D7) 2-10
Bus Buffer/Driver 2-118
Input Strobe (DISTR, DISTR) 2-129
Output Strobe (DOSTR, DOSTR) 2-129
Rates 2-39
Record Architecture 3-10
Set Ready (DSR) 2-131
Data Flow (System) 2-6
Data Flow (System) 2-6
DC 1 (Device Control 1) 2-81
DC 2 (Device Control 2) 2-81
DC 3 (Device Control 3) 2-81
DC 4 (Device Control 4) 2-80
DC Output 2-34
DEL (Delete) 2-81
Delete (DEL) 2-81
Device Control 1 (DC 1) 2-81
Device Control 2 (DC 2) 2-81
Device Control 3 (DC 3) 2-81
Device Control 4 (DC 4) 2-80
Digital Output Register (DOR) 2-91
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