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SECTION 15

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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.

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

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.

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