devices File

The devices file contains an item for every terminal or printer device recognized by the D3 System. The actual escape sequences produced by @ functions in BASIC and PROC are defined within these device drivers.

Synonym(s)

dv

Description

The item-IDs are device codes (for example, WY-100 is the WYSE WY-100 terminal). The define-terminal command defines additional terminals and printers.

The attributes in the devices file for terminals are:

Attribute

Name

Description

0

 

Full name and model number information for device.

1

desc

Description of device

2

bks.ss

ASCII character for backspacing, number of columns, number of rows

3

c.add

Device x-y cursor addressing statement will begin with ’=m’

4

cac

Cursor Addressing Code

5

 

CRT Functions statement will begin with ’=s’

6

cls

@(-1) Clear screen and home

 

NOTE

This file contains terminal specific code that can cause your terminal to lose its characteristics during updates. When an item in this file is modified, the term (c command must be run to recompile the device definition.

The attributes in the devices file for printers are:

Attribute

Name

Description

0

 

Full name and model number information for device.

1

desc

Description of device

2

points

ASCII character for backspacing, number of columns, number of rows

3

lpi

Device x-y cursor addressing statement, If applicable, will begins with ’=m’ otherwise the statement will contain a ’!’ (comment)

4

lpp

Cursor Addressing Code, if applicable, otherwise the statement will contain a ’!’ (comment)

5

orient

CRT Functions statement will begin with ’=s’,if applicable, otherwise the statement will contain a ’!’.

Example(s)

Show all the devices defined.

sort only devices

CRT Control Language (CCL)

D3 has a universal device function, the @() to specify certain terminal and printer commands.

To perform a certain feature the programmer will use the equivalent @() function. At runtime, the system will look up the function and substitute the proper character string then output it to the device. In this way, the compiled BASIC program does not have to contain hardware specific commands.

This method of device independence is achieved by creating many look-up tables - one for each device. Each look-up table contains over 300 different popular device functions, features and modes. Each function, referred to as an @() function has a corresponding character string which is output to the device. Such a look-up table is considered to be a "script" written in D3’s CRT Control Language or CCL.

D3 has expanded the uses of the @() functions to include printer devices as well.

Typical uses of the @() function:

Example 1

Example 2

Example 3

A CCL script contains of several sections, each section contains sentences, each sentence contains data elements

The specific information for creating a CCL script is contained in the crt.control.language item in the dm,devices, file. The information can be displayed by using:

op dm,devices, crt.control.language.

See Also

.font Command

@() Function

assignfq (UNIX) Command

choose.term Command

define-terminal Command

listabs Command

term Command

term-type Command

termp Command