• Registered: 2015-06-29
  • Posts: 366

Topic: ZX spectrum on bare-metal Pi

I missed this one, it looks very interesting for beeper music. I haven't tested it yet though.

http://zxmini.speccy.org/

ZXBaremulator is the first complete ZX Spectrum 48K bare-metal emulator for the Raspberry Pi computers.

Emulator features

- Support all Raspberry Pi models (A, B, A+, B+, 2, 3, Zero).
- Includes 55 classic 48K Spectrum games.
-  Precise Z80 emulation (undocumented opcodes, hidden WZ register, bits 3-5 from 'F' register).
-  Precise Spectrum 48k emulation (full border, real-time screen drawing without double buffer, contended memory, floating bus, hi-res color effects).
-  Kempston joystick emulation using a PS3 DualShock gamepad in USB mode (no Bluetooth supported).
- Accelerated tape loading from virtual TZX tapes (when possible). Original tape loaders are preserved.
-  Beeper emulation using the PI PWM capabilities, present on 3.5mm socket (no HDMI sound, sigh!).
-  No Linux needed!. Super-fast loading from µSD.

my 1-bit music - my soundcloud
  • Registered: 2015-06-29
  • Posts: 366

Re: ZX spectrum on bare-metal Pi

I've just tested it. It works rather well:

- instant boot
- easy to use
- all the games I tried were working

but for music lovers, there are some drawbacks:

- for general tap with loading code, unless you add some pause at the beginning, it will cut 1/2 second of the music when it loads, I don't know why
- all the engines I've tried seems to replay well, at the correct speed. However, on some of them, there is a high carrier noise in the background
- it's a pure zx48, so no AY music sad

It's a very cool project anyway.

my 1-bit music - my soundcloud
  • utz
  • utz
  • Administrator
  • Offline
  • Registered: 2015-06-28
  • Posts: 1,005

Re: ZX spectrum on bare-metal Pi

Nice project, bummer about the sound emulation. Might be worth a try porting it to the C.H.I.P, though the timing issues on that machine will probably ruin the emulation.

website | bintracker | github | bandcamp | soundcloud

utz's Website

  • Registered: 2015-06-29
  • Posts: 366

Re: ZX spectrum on bare-metal Pi

For the sound, I guess building a kind of new output to bypass the jack, with a low pass filter could maybe do the job, I guess there is one on the original ZX?

For the late beginning of the song, probably contacting the author of this project.

my 1-bit music - my soundcloud
  • utz
  • utz
  • Administrator
  • Offline
  • Registered: 2015-06-28
  • Posts: 1,005

Re: ZX spectrum on bare-metal Pi

ZXBaremulator uses the core from JSpeccy, which iirc has the same problems with beeper sound. Sound from the Pi itself should be fine.

website | bintracker | github | bandcamp | soundcloud

utz's Website