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Sinclair ZX Spectrum
128K Plus 3

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This was the last (but not the last launched model) ZX Spectrum model, launched in 1988 by Amstrad. This computer have a internal 3" disk drive. Each disk side have 173K free for programs. This computer may use all the software for 48K Spectrum (I think that +3 have some incompatibilities) and all 128K software (if it doesn't use the special commands to work with the 128K/128K+2 RAMdisk). This computer doesn't have the 128 BASIC, but the +3 BASIC, witch have the +3 DOS, to work with the disk drive. Tape is treated in +3 BASIC as T: drive and the RAMdrive as the M: drive. A addicional external disk drive could be connected to the +3 back. The external disk drive is treated by +3 DOS as B: drive.
+3 have 64K ROM instead of 32K like the +2 and was capable to use Centronics printers.
With this model the ZX Interface 1 can't be used. All the peripherals used in the early models must be tested to see if they work with +3 The +3 edge connector is incompatible with 48K edge connector but a fix board can be made to change this.

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Processor:
-Zilog Z80A running at 3.5Mhz
RAM:

-128K. Paged in 16K chunks.
Storage:

-Cassete tapes at 1200 baud.
-RAM disk
-Disk Drive 3" (160K)
Firmware:

-16K ZX colour BASIC
-32K +3 Basic
-16K +3 DOS
Screen:

-Text 32x22 16 colors
-Graphics 256x192. Color resolution is 32x22x16
Sound:
-3 channels AY-3-8912 chip
-Beeper
Other:

-Expansion connector
-TV Modulator
-Reset button
-MIDI/RS232
-RGB/peritel monitor
-Aux
-Sound
-Disk Drive (FD-1)
-Parallel port
-Joysticks SJS1

This page was updated at 03-03-2003