Sinclair ZX Spectrum User Manual

Chapter 2
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be fitted with a ROM containing a modified version of Spectrum BASIC and for devices
that were designed to supplement or interrupt the Spectrum’s BASIC ROM to be
connected behind it and to operate on the modified version instead, e.g. Multiface,
Centronics printer interface. When used in this configuration, the SPECTRA interface
should ideally be connected immediately behind the Spectrum, but this may not
always be possible, e.g. when a ZX Interface 1 is also connected. In such a case, the
ZX Interface 1 would not be able to intercept the ROM fitted on the SPECTRA interface
and so its extended BASIC commands would not be available.
Configuration switches
The SPECTRA interface contains 6 switches that are used to enable / disable the
various facilities it provides. The configuration switches are numbered 1 to 6 and
perform the following functions:
1. Enables sound output through the television’s speaker(s).
2. Enables an onboard ROM to override the Spectrum’s ROM.
3. Enables an onboard ROM or ROM cartridge to extend the Spectrum’s ROM.
4. Enables the RS232 socket.
5. Enables the Kempston joystick socket.
6. Enables the new display modes.
A facility is disabled when its control switch is set to the off position (the slider pushed
to the left), and enabled when set to the on position (the slider pushed to the right).
The use of each switch is described in the chapter that corresponds to the facility it
controls. When operating the switches, avoid placing pressure downwards as this can
damage them and ultimately prevent them from working reliably.

Sinclair ZX Spectrum Specifications

General

Brand	Sinclair
Model	ZX Spectrum
Category	Desktop
Language	English