shaymanjohn/speccymac

ZX Spectrum emulator for OSX, written in Swift

SpeccyMac

ZX Spectrum emulator for macOS (currently 48K only), written in Swift 5.

Requires Xcode 13 to build.

Please see issues to check known problems. Please raise more if yours isn't there.

Collaborators welcomed.

Performance

• Pretty good when running a release build (quite a bit slower on a debug build).
• Sound tends to be a bit scratchy, don't know why yet.
• Kempston joystick is emulated on cursor keys and tilde (key between shift and Z) to fire.

Lots of things still to do

• Joypad support
• Hi-res border
• Check all timings
• Contended memory
• Add zip support
• Add Z80 file support
• Add TZX/SZX file support
• 128K mode
• AY sounds
• Lots more unit tests

Acknowledgements

• All included games have distribution permitted, see: http://worldofspectrum.org/archive.html
• AudioStreamer code by jmayoralas, https://github.com/jmayoralas/Sems
• F-register look up tables from Fuse, http://fuse-emulator.sourceforge.net/

speccymac's Issues

Crash in some games

Cobra and Green Beret
Must be caused by 1 or more incorrect instructions in the Z80 class

No graphics other than border colour which fills the whole window

Running the released version on an M1 MacBook Air / Monterey

I see a window with the "Load game" button in the top right corner. The window is a grey colour like the Speccy's "white".

On loading any game I see no graphics but can hear all of the ones that start playing a tune or emitting sound effects. Games which set the border colour change the whole window to that colour. Manic Miner changes the window colour as the music plays, but nothing else is visible.

Images for README

Some Z80 instructions not emulated

Need to add all missing instructions, including the 'hidden' ops

No sound

Evaluating sound options

Add support for .tap tape image files

I think .tap is the next file format that is both common and easy to implement since it's not an audio format and doesn't handle fastloaders.

I intend to work on it so you can assign it to me if you wish.

There are two copies of "48.rom" and three copies of "manic.sna" in the repo

speccyMac/48.rom
speccyMac/speccyMac/Games/manic.sna
speccyMac/speccyMac/48.rom
speccyMac/speccyMac/manic.sna
speccyMac/manic.sna

I'm assuming the copy of the rom in the root directory is the surplus one?

Sound scratchy intermittently

Add a file dialog to load arbitrary snapshot files

Currently the emulator can only use the snapshot files compiled into it.
Users can only load new games by modifying the code and recompiling.

A file dialog is needed so we can load snapshots directly from the Downloads or Documents folder, etc.

Both a menu and allowing files to be dragged and dropped onto the emulator window would be good ways to implement it.

Border colour doesn't always fill, and leaves empty lines

Now we've moved to a line based border (to allow hi-res border changes), often there are lines left in the border.
Faulty algorithm to blaim?

Symbol Shift not mapped

Symbol Shift appears to not be mapped - Caps Shift is mapped to Shift, but I can't find Symbol Shift at all

After one game snapshot fails with an unemulated instruction, subsequent snapshots will not run

For instance my .z80 of Chase HQ stops with:

Unemulated Instruction:

RRC (HL)
Instruction number: E
Section: z80+cb

After clicking on OK choosing any other snapshot from the Load button causes the snapshot to load but not to run.

Add support for snapshots inside ZIP archives

I've actually got ZIP parsing and extracting working in pure Swift in a standalone tool.
Just need to use that logic to make a new Loader.

Support for .z80 snapshot format

The .z80 snapshot format is probably the next easiest to implement after .sna since it's not an audio format like .tzx and .tap.

It does use compression though but it's a very simple run-length encoding.

I'm gonna start work on this now.

Three times?

$ find . -name manic.sna -ls
22577631      104 -rwxr-xr-x    1 polluks          staff               49179  4 Aug 18:28 ./manic.sna
22577679      104 -rwxr-xr-x    1 polluks          staff               49179  4 Aug 18:28 ./speccyMac/manic.sna
22577665      104 -rwxr-xr-x    1 polluks          staff               49179  4 Aug 18:28 ./speccyMac/Games/manic.sna

Adding a new game snapshot to the Games folder and the filename array in Spectrum.swift but not to the project detects no error

I'm an old programmer from the Speccy and Amiga days using this project to try to get up to speed with old school style programming on new systems after twenty years away, so please excuse me making tons of newbie mistakes.

Before I realized I had to add any new game to the project via the XCode GUI as well as to the folder structure and the source code, I could not figure out what was wrong.

The debug output says "loaded" even though it failed.