ZX80 Joystick Interface

[albertusj]

Found it!

viewtopic.php?t=2910

Perhaps I'll do something like THIS instead:

https://www.sinclairzxworld.com/viewtopic.php?t=1793

It would be far more useful for the game controller to map to the keys but in a neat way.

[mrtinb]

Oh - that’s my thread

[mrtinb]

http://forum.tlienhard.com/phpBB3/viewt ... key#p36489

And to that interface I have connected a JoyKey bought from the German ZX-Team. Here you can associate any key for any direction.

[1024MAK]

Perhaps I'll do something like THIS instead:

https://www.sinclairzxworld.com/viewtopic.php?t=1793

It would be far more useful for the game controller to map to the keys but in a neat way.

Is this for a ZX80, a ZX81 or a ZX Spectrum?

Only there may be a problem...

On a ZX80

Why you can’t connect an external keyboard or a joystick mapped to any of the keyboard keys to the expansion edge-connector and expect it to work...

On the ZX80 board, IC10, a 74LS365 provides the Ear and keyboard data to the Z80 CPU.
The 74LS365 will override any data on the expansion port at any I/O address that it responds to.

So unless you remove this chip, you will not be able to use an external keyboard or a joystick mapped to any of the keyboard keys that is connected to the expansion edge-connector.

On a ZX81 or ZX Spectrum model that uses a Ferranti ULA (16K, 48K, plus, 128K (toastrack), +2 (grey)

There is no problem using either an external keyboard, or a joystick interface that maps to the keyboard via the expansion edge-connector, as the ULA chips don’t override an external keyboard / joystick interface unless of course you press a key on the computer’s original keyboard...

ZX Spectrum +2A, +2B, +3 or +3B

A similar problem to the ZX80, only this time, the problem is the Amstrad designed gate array chip.

Mark

[RWAP]

Surely it would make more sense for a new joystick interface to support the same joystick controls as the ZXPand+ - the ZXPand+ seems to be one of the most widely used interfaces on a ZX80 and ZX81 today (because of SD support); so it makes sense to mimic it's joystick support

[albertusj]

Thank you, everyone. I'm building the interface to be Kempston compatible.