Editing DECmate I (section)

== Hardware ==
The VT278 contains the CPU board, the keyboard interface, the video monitor board and the power supply. DEC's block diagram shows the 6120 microprocessor, 32K words of main memory, a 100 Hz real-time clock, the CRT controller and the keyboard controller on the CPU board.<ref name="td11" />

The 6120 runs user programs from main memory and uses a second 32K-word address space, called control panel memory, for self-test, terminal emulation, the floppy bootstrap, the display buffer and the CRT control registers.<ref name="td11" /> The DECmate II specification compares the two machines: the DECmate I runs its 6120 at 5 MHz and has 4K words of fitted control memory, against 8/4 MHz and 32K words on the DECmate II.<ref name="dm2spec" />

{| class="wikitable styled-table" style="width:70%; text-align:center;"
|+ '''DECmate I boards and assemblies (VT278 print set MP-00900)'''
! Assembly !! Part !! Notes
|-
| CPU module || M8436 || 6120, memory, CRT, keyboard, printer and diskette control
|-
| Communications adapter || M8437 || DP278 option
|-
| I/O connector board || 5414322 || Carries the 72-pin module connectors
|-
| Keyboard || 70-14653 assembly, 5413404 board || Keycap sets for word processing and several languages
|-
| Monitor board || 5414131 || Drawn as the VT100 monitor board
|-
| Power supply || H7836-A (120 V), H7836-B (220 V) || +5 V 2.5 A, +12 V 2 A, −12 V 0.25 A
|}
<ref name="mp900" />

The keyboard is joined to the CPU board by a 3-wire cable. Two wires carry +12 V and ground for the keyboard logic; the third is a bidirectional serial line.<ref name="td13" /> The power supply takes 120 V or 220/240 V, selected by a slide switch on the rear panel, and a second switch selects 50 Hz or 60 Hz.<ref name="td13" />

=== Display ===
The display is 24 rows of 80 characters or 14 rows of 132. Each character can be given increased intensity, underlining, blink or reverse video.<ref name="td13" /> The screen brightness is set from the keyboard in SET-UP mode, in 16 steps.<ref name="sam36" />

=== Storage ===
A 37-pin connector at the rear of the VT278 takes one or two dual diskette drives.<ref name="td13" /> Each RX02 diskette holds 256,256 12-bit words formatted on 77 tracks.<ref name="sam14" /> The printer port is a 25-pin connector; it starts at 9600 baud and can be set from 50 to 19,200 baud under program control.<ref name="td13" />