ZX Spectrum Next's ZX81 Core

EeDee
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ZX Spectrum Next's ZX81 Core

Unread post by EeDee »

Upon trying the ZX Next's ZX81 core I'm finding that the keyboard characters don't print what you'd expect. For example SHIFT and 3 yields FAST instead of THEN.
As I cannot find any mention of a problem I'm wondering what I'm missing.
Can anyone shed some light?

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pgimeno
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Re: ZX Spectrum Next's ZX81 Core

Unread post by pgimeno »

It looks like the keys are mapped Spectrum-style, probably by replacing the ROM. For example, shift+ASDFG yields the same STOP NOT STEP TO THEN sequence as in the Speccy, the semicolon is in shift+O instead of shift+X, and so on.

My guess is that they made this to make the keywords and symbols match those printed in the keys of the Next keyboard.

Stinky
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Re: ZX Spectrum Next's ZX81 Core

Unread post by Stinky »

Getting a bit inception...

EeDee
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Re: ZX Spectrum Next's ZX81 Core

Unread post by EeDee »

Not much use to me then.
Thanks @pgimeno

RichardHallas
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Re: ZX Spectrum Next's ZX81 Core

Unread post by RichardHallas »

Just spotted this thread.

I haven't personally used the Spectrum Next core on a MiSTer, so the following is based on use of the real machine.

The Spectrum Next's ZX80 and ZX81 emulators have a choice of keyboard mappings. When either is running, if you press the NMI button to bring up the NMI menu, it offers a Keymap menu option; if you choose this, then (a) it shows you a graphical representation of the current keyboard mapping, and (b) it allows you to toggle between the remapped and standard layouts by pressing X.

I assume the MiSTer core can invoke the Spectrum Next's NMI menu(s)? I hope so. Assuming it can, this is by far the easiest way to see and change the keyboard mapping. Alternatively, you can revert to the original ZX81 keyboard mapping by typing PRINT USR 8255, or switch back to the new mapping by typing PRINT USR 8252.

There's more info about all this on Paul Farrow's website (http://www.fruitcake.plus.com/Sinclair/ ... w_ZX81.htm), as he wrote the ZX80/81 emulators: they're actually Interface 2 cartridge ROMs for the Spectrum 128, and are included on the Spectrum Next with his permission. However, the Keymap option on the Spectrum Next's NMI menu is a feature of the Next itself, and is not part of Paul Farrow's software; it's a quality of life bonus feature to make the emulators easier to use on the Next.

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Re: ZX Spectrum Next's ZX81 Core

Unread post by EeDee »

Thank you for that @RichardHallas, The latter method works fine.
It's taken me a while to try it and reply as I managed to incapacitate my DE10 Nano to the point of uselessness 🙄

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