MiSTer FPGA Forum

Hi,

I've tried different combinations of settings and game versions to play Blinky's Scary School in spectrum core, and none of them works for me. Tested 48/128k mode and tap/tzx/sna tosec files. All of them get stuck in the main menu and is not possible to start playing.

Does it work for you? Any suggestion for compatible settings?

Thanks

This is due to a bug in the core's implementation of port 0xFE. I was suspicious that there was no Issue 2 / Issue 3 selector in the menu, and this has confirmed my fears.

If you go here: https://worldofspectrum.org/faq/referen ... erence.htm and scroll down to where it says "Bit 6 of IN-Port 0xfe is the EAR input bit", there's a test program there. This core fails the test; the result is that you're in a Spectrum emulator.

The menu of Blinky's Scary School relies on the 0xF7FE port returning 0xBE, 0xBD, 0xBB or 0xB7 depending on the key pressed; however this core always returns 0xFE, 0xFD, 0xFB or 0xF7 for the corresponding keys (bit 6 stuck to 1).

Abu Simbel Profanation had a similar problem that rendered it unplayable with the keyboard in some machines/emulators. Indeed it is unplayable in this core too.

If you have the ADC module, you can try playing audio through the ADC input to see if you can select an option (that should force bit 6 of the port to flicker, returning the expected values sometimes). I don't know if the game will work after that.

Edit: Also, the ZX Next core gets this right, so you can use it instead.

Thanks for the info. As soon as i've played audio across the adb port, the game has worked perfectly. I have also tried to replace CP values next to IN A,FE and it works too. It seems that bit 6 is set always to 1 if no audio is received from adb input. Maybe someone who knows the code can add a menu option to change this behavior.

It's not exactly a menu option to make this optional; it's something to be fixed in order for the core to behave as a real Spectrum. It can be fixed to a certain model, Issue 2 or Issue 3, or the model can be a menu choice, but the current behaviour does not match either, causing compatibility issues.

If someone can post it to the GitHub issue tracker, that'd be nice. I left GitHub for good.

https://github.com/MiSTer-devel/ZX-Spec ... Ter/issues

I have already open the issue:

https://github.com/MiSTer-devel/ZX-Spec ... /issues/21

Thanks again

EDIT: Sorgelig has fixed the problem, now it works as expected for an issue 3

Thanks! It's something.

Sadly, Abu Simbel Profanation requires Issue 2 behaviour to work. Ideally it should be a menu choice.

ops, it's true, i've tested my abu simbel version and probably it's patched for issue 3 because it works with these changes. I reopen github issue to see if anything can be done.

Thanks