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ZX Spectrum +2A

My speccy with floppy My first computer which is due to my experiences. And I'm bounded a lot. This page is a little tribute to this great small computer. But it's a history ... (for me)
From simple playing games I've started to pay attention to more practical usage of my Speccy. Such as plotting Printed Board Circuits, writing texts and making my fist steps with the computer based music. In next table are listed some of my programs and interfaces. Don't hesitate and ask me about details. But as soon as possible, because time is running...


Programs for ZX Spectrum +2A Description
Floppy disk formatter versatile routine, which I used to format single side and double side and both 40 and 80 tracks.
D40 simple file converter between D40 (Slovak version of Speccy Didaktik Gama) +3 DOS (yes, that's the name of disk system in Speccy +2A) formats.
CBD >>> HPGL Colorgraf 512 plotting printed board circuits created in CBD software on Colorgraf Aritma 512 plotter (HP 7475A compatible). Single and Double side boards.
Interfaces for ZX Spectrum +2A Description
Floppy disk interface based on I8272. Its small size allows to hide it inside Speccy. After connection the computer starts to work as ZX Spectrum +3.
Sound cardSound card for UR4 (based on 8255), which consists of four eight-bit DA converters. A soft, created by one of my friends, for playing MOD files supports this card.
AD/DA eight-bit AD/DA converter. I used to play Specdrums with it.
UR4UR4 three eight-bit port interface for ZX Spectrum
AY-3-8910 (jpeg 9kB) the schematic of stereo three channel sound generator
Floppy disk driver (jpeg 89kB)
PCB with FDD connector component and solder side.
PCB without FDD connector component and solder side.
Component plan and relocation of output signals for version without a FDD connector on PCB.
If anyone wants to see how it looks when it is built in then there are some pictures with an overview, closer look, board detail and connector detail. 		the schematic of ZX Spectrum +2A floppy disk interface based on I8272 (uPD 765). After connection the +2A becomes a real +3A and +3DOS system runs.
In the following table is the list of memory 32B PROM 74S188. The same schematic can be found in the journal Amaterske Radio line A 12/1989 page 457.
address 00H 01H 01H 02H 02H 03H 03H 04H 04H 0DH 0DH 0EH 0EH 0FH 0FH 00H 00H
address 10H 01H 02H 03H 04H 05H 06H 07H 08H 09H 0AH 0BH 0CH 0DH 0EH 0FH 00H

Power Supply Unit connector of ZX Spectrum +2A

DIN 6 Female on the back of computer
   __----  ----__
  /      --      \
 / -12V      5V   \
 |                |
 | 12V  GND   5V  |
  \              /
   \    12V     /
     ---____---
  5V 2A
 12V 200mA
-12V 50mA

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