Timing issues

[ghost]

GoSpeccy is unable to pass the following timing tests:

http://www.zxspectrum4.net/downloads/timing_tests/
http://homepage.ntlworld.com/mark.woodmass/z80tests.tap

The links come from: http://www.worldofspectrum.org/forums/showthread.php?t=30908&page=2

An emulator (with source code available) which can pass majority of these tests is: http://jspeccy.speccy.org/

[ghost]

GoSpeccy is now able to pass all but the last two timing tests from [http://www.zxspectrum4.net/downloads/timing_tests/].

Emulation of 48k Spectrum should be nearly on par with JSpeccy 0.87. A notable exception is that GoSpeccy is not emulating MEMPTR (yet). Overscan Demo [http://www.worldofspectrum.org/infoseekid.cgi?id=0007636] is working OK.

Commit: http://github.com/0xe2-0x9a-0x9b/gospeccy/commit/f3ccd13b1bbf6a826430d3a38c79d791fbf6e41e