Soundcard and joystick interface; AY-3-8910/12; ZX Spectrum

AY-Sound and Joystick interface "ORPHEUS"

Sound card for your ZX Spectrum 48KB and compatible computers - Winter edition

(Assembled, soldered and tested device)

The board combines two indispensable devices:

1. Three-channel audio interface with chip AY-3-8910/12 or analog, it is functionally fully compatible with a similar circuit in ZX Spectrum 128K
2. Joystick interface, emulating four standards a joystick!

Properties:

- Small sizes, compact design to directly fit into the ZX Spectrum edge connector
- Sound chip AY and joystick interface – ALL IN ONE
- Emulation of four joystick connection modes
- Possibility to block the AY chip
- Switching ACB / ABC stereo sound channels
- The full-through bus to the connector is identical to the ZX Spectrum edge connector
- RESET button on board

Joystick interface:

Allows to connect a Quickshot-compliant joystick (4x direct + 1x fire) through the 9-pin D-SUB connector.
The 5V supply voltage for the autofire function is also available on the connector. The joystick switches must
be connected to the ground (active log. levels 0), pull-up resistors are not necessary in the joystick, they are
connected to the board.

The device emulates the joystick connection to your computer in four standard modes:

1) Interface 1 (Sinclair 1 LEFT) – keystroke emulation 1 to 5
2) Interface 2 (Sinclair 2 RIGHT) – keystroke emulation 6 to 0
3) Cursor (Protek) – keystroke emulation 5,6,7,8,0
4) QAOPM – keystroke emulation QAOPM
All of these methods are common in games or other programs. The interface can be used together with
the keyboard.

Sound interface:

It is possible to mount the AY-3-8912 chip in the 28-pin DIP case and the AY-3-8910 in a 40-pin DIP
case. In addition, it is now possible to purchase and install even more modern versions of JFC95101,
KC89C72 and WF19054, all in a 40-pin DIP case. These circuits are characterized by lower energy
consumption and more pronounced sound than the old AY chips.

The circuit is full compatible with the ZX Spectrum 128KB, the sound chip operates on the same 49149
and 65533 port addresses. As opposed to Spectrum 128KB, line A5 is also introduced into the address
decoder so the interface does not collide with the current D40/D80 floppy disk drive.

Complete documentation to download: http://css-electronics.8u.cz/ZX_Spectrum_projects.html