# Failures

If you're having problems with the sound, please see the Sound section of the Emulation page.

Things known to not work very well, or at all, but may in future :-

- Need to cope with laptop and MacOSX keyboards better.
- `BBCBASIC.COM` runs slow.

Things which don't work, and may never work, and why :-

- Toado doesn't sound right. When you move the frog, it sets channel 1 to a loud tone and then immediately silences all 3 tone channels (so the fly noise, the twinkle noise and the frog movement tone are all silenced). However, on a real MTX, a crackly sound is heard. This is because on a real MTX the sound chip responds immediately, but in MEMU I fabricate waveform when PortAudio periodically asks for it. This is very tricky to fix.
- Programs which directly do low level disk I/O to the FDX style floppy disk controller, such as the FDX boot ROM.
- Programs which do direct access to the cassette tape ports, such as certain games loaders.
- Programs which depend on the DART, such as `KERMIT.COM`, `CONTACT.COM`, `CONTVI.COM` and the NODE ROM now have a limited degree of functionality, based upon their emulation in terms of files/devices/pipes, without respect to baud rate or real serial line control signals.
- The Speculator support is far from robust.