SECTION 15

15 Commodore Enhancements to CP/M 3.0

TABLE OF CONTENTS * 15.1 KEYBOARD ENHANCEMENTS * 15.1.1 Defining a Key * 15.1.2 Defining a String * 15.1.3 Using ALT Mode * 15.2 SCREEN ENHANCEMENTS

15.1 KEYBOARD ENHANCEMENTS

Commodore has added a number of enhancements to CP/M 3.0. These enhancements tailor the capabilities of the Commodore 128 to those of CP/M 3.0. This section describes these enhancements.

Any key on the keyboard can be defined to generate a code or function, except the following keys:

• {left shift} key
• {right shift} key
• {C=} key
• {ctrl} key
• {restore} key
• {40/80 display} key
• {caps lock} key

In defining a key, the keyboard recognizes the following special functions. To indicate these functions, hold down the {ctrl} key and the {right shift} key and press the desired function key simultaneously.

Key	Function
{crsr left} key	Defines key
{crsr right} key	Defines string (points to function keys)
{alt} key	Toggles key filter

15.1.1 Defining a Key

A user can define the code that a key can produce. Each key has four possible definitions: Normal, Alpha Shift, Shift and Control. The Alpha Shift is toggle on/off by pressing the {C=} key. After entering this mode a small box appears on the bottom of the screen. The first key that is pressed is the key to be defined. The current HEX (hexadecimal) value assigned to this key is displayed and the user can then type the new HEX code for the key, or abort by typing a non-HEX key. The following is a definition of the codes that can be assigned to a key. (In ALT mode, codes are returned to the application; see "Using ALT Mode" below, in paragraph 15.1.3.)

Code	Function
00h	Null (same as not pressing a key)
01h to 7Fh	Normal ASCII codes
80h to 9Fh	String assigned
A0h to AFh	80 column character color
B0h to BFh	80 column background color
C0h to CFh	40 column character color
D0h to DFh	40 column background color
E0h to EFh	40 column border color
F0h	Toggle disk status on/off
F1h	System Pause
F2h	(undefined)
F3h	40 column screen window right
F4h	40 column screen window left
F5h to FFh	(undefined)

15.1.2 Defining a String

This function allows the user to assign more than one key code to a single key. Any key that is typed in this mode is placed in the string. The user can see the result of typing in a long box at the bottom of the screen.

Note: Some keys may not display what they are. To provide the user with control over the process of entering data, the following five special key functions are available. To access these functions, press the {ctrl} and {right shift} keys and the desired function keys.

Key	Function
{return}	Complete string definition
{+} (on main keyboard)	Insert space into string
{-} (on main keyboard)	Delete cursor character
{left arrow}	Cursor left
{right arrow}	Cursor right

15.1.3 Using ALT Mode

ALT mode is a toggle function (that is, it can be switched between ON and OFF). The default value is OFF. This function allows the user to send 8-bit codes to an application.

15.2 SCREEN ENHANCEMENTS

The screen in CP/M 3.0 emulates an ADM31 terminal. The following screen functions emulate ADM 3A operation, which is a subset of ADM31 operation.

CTRL-G	Sound Bell
CTRL-H	Cursor left
CTRL-J	Cursor down
CTRL-K	Cursor up
CTRL-L	Cursor right
CTRL-M	Move cursor to start of current line (CR)
CTRL-Z	Home and clear screen
ESC = RC	Cursor position where R is the row location (with values from space to 8) and C is the column location (next values from space to 0), referenced to the status line.
Additional functions in ADM31 mode include:
ESC T} ESC t}	Clear to end of line
ESC Y} ESC y}	Clear to end of screen
ESC :} ESC *}	Home and clear screen (including the status line)
ESC Q	Insert character
ESC W	Delete character
ESC E	Insert line
ESC R	Delete line
* {esc} {esc} {esc} [color#] sets a screen color from a table of 16 possible color entries. The [color#] is set as follows:
20h to 2Fh	character color
30h to 3Fh	background color
40h to 4Fh	border color (40 column only)
The visual effects associated with following functions are visible only in 80-column screen format:
ESC >	Half intensity
ESC <	Full intensity
ESC G4	Reverse video ON
* ESC G3	Turn underline ON
ESC G2	Blink ON
* ESC G1	Select the alternate character set
ESC G0	All ESC G attributes OFF
* Note: This is NOT a normal ADM31 sequence.

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The sections in this chapter provide a summary of the structure and wideranging capabilities of CP/M 3.0. Detailed information on any facet of CP/M is given in the Digital Research, Inc. book, CP/M Plus User's Guide. To obtain a copy of this, refer to the coupon enclosed in the box in which the Commodore 128 is supplied.