Category: spectrum

Essential API

+3DOS Essential API

Additional API

+3DOS Additional API

Low Level API

+3DOS Low Level API

Spectrum Memory Map Overview

Spectrum Memory Map

Display File

The display pixel format

+3DOS File Header

The +3DOS File Header

Display Attributes

The display attributes specifying colour information

Error Codes

The +3DOS Error Codes

Screen

The Spectrum’s screen memory layout

System Variables

System variables

Basic

Notes on BASIC for the Spectrum

+3 DOS

Notes on the Disk Operating System for the Plus 3

DOS_INITIALISE

Initialise +3DOS

DOS_VERSION

Get the DOS issue and version numbers

DOS_OPEN

Open and/or Create a file

DOS_CLOSE

Close a file

DOS_ABANDON

Abandon a file

DOS_REF_HEAD

Point to header data for this file

DOS_READ

Read bytes from a file into memory

DOS_Write

Read bytes from a file into memory

DOS_READ_BYTE

Read byte from a file, check for soft-EOF

DOS_WRITE_BYTE

Write byte to a file

DOS_CATALOG

Get the disk catalog

DOS_FREE_SPACE

Get free space on drive

DOS_DELETE

Delete a file

DOS_RENAME

Rename a file

DOS_BOOT

Boot from disk

DOS_SET_DRIVE

Set the default drive

DOS_SET_USER

Set the default user

DOS_GET_POSITION

Get the file pointer

DOS_SET_POSITION

Set the file pointer

DOS_GET_EOF

Get the end of file (EOF) position

DOS_GET_1346

Get current cache/ramdisk location

DOS_SET_1346

Rebuild the sector cache and RAM disk

DOS_FLUSH

Write any pending data to this drive

DOS_SET_ACCESS

Change access mode of an open file

DOS_SET_ATTRIBUTES

Set a files attributes

DOS_OPEN_DRIVE

Open drive as a single file

DOS_SET_MESSAGE

Enable/disable disk error messages

DOS_REF_XDPB

Point at XDPB for this drive

DOS_MAP_B

Map drive B to unit 0 or 1

DD_INTERFACE

Check for the disk drive interface

DD_INIT

Initialise the disk driver

DD_SETUP

Setup disk parameters

DD_SET_RETRY

Set try/retry count

DD_READ_SECTOR

Read a sector

DD_WRITE_SECTOR

Write a sector

DD_CHECK_SECTOR

Check a sector

DD_FORMAT

Format a track

DD_READ_ID

Read a sector identifier

DD_TEST_UNSUITABLE

Check disk is suitable to write to

DD_LOGIN

Log in a new disk

DD_SEL_FORMAT

Select a standard format

DD_ASK_1

Check to see if unit 1 is present

DD_DRIVE_STATUS

Check drive status

DD_EQUIPMENT

Ask what type of drive

DD_ENCODE

Set copy protection encode routine

DD_L_XDPB

Initialise XDPB for a given format

DD_L_DPB

Initialise DPB for a given format

DD_L_SEEK

Seek to required track

DD_L_READ

Low level uPD765A read command

DD_L_WRITE

Low level uPD765A write command

DD_L_ON_MOTOR

Turn on motor

DD_L_T_OFF_MOTOR

Start motor off timeout

DD_L_OFF_MOTOR

Turn off motor

Spectrum +2A/+3 Memory Map

Spectrum +2A/+3 Memory Map

Spectrum 128K/+2 Memory Map

Spectrum 128K/+2 Memory Map

Spectrum 48K Memory Map

Spectrum 48K Memory Map

Spectrum Basic Memory Map

Spectrum Basic Memory Map

BASIC Loader

BASIC .TAP loader

Basic Tokens

Tokens used to store BASIC programs in memory

Calculator

Enter the floating point calculator

Clear the Screen

Example code to clear the Spectrum’s screen

Clear the screen

Clear the whole display area

Collect Character restarts

Collect Character and Collect Next Character restarts

ERROR

Error restart

Get address of character on screen

Calculate the true address on screen of a character

Tape Loaders

Notes on various program loaders

Make BC Spaces

Creates BC free locations in the workspace

Maskable Interrupt

The Maskable Interrupt Handler

PRINT_A

Write A to current output channel

Managing the Screen

How to manipulate the Spectrum’s screen

Set the border colour

Example code to set the border colour on the Spectrum’s screen

START

Restart the machine

Determine Machine Type

Detect which model of Spectrum the code is running on

TAP

Example code to load a machine code program in TAP format

TAP Format