CSpect:known bugs

CSpect V2.15.02

• sprites: the collision bit is not implemented (intentional for performance reasons)
• sprites rendering is not one-scanline-buffer delayed and all changes in sprites affect current scanline (intentional for performance reasons)
• (changed a bit in 2.15.02) modifications to NextRegs done in copper propagate to rendering usually only once per scanline, the state for rendering is sampled around end of right border area before h-blank area after h-blank area or in left-border, affecting previous line instead of next (palette changes, X/Y offsets, etc) (intentional for performance reasons)
• modifications to NextRegs done by CPU propagate to rendering usually only once per scanline, usually retroactively for whole current scanline (mostly intentional for performance reasons)
• blending modes: quite wrong (worse than 2.14.08), but the test is not comprehensive (HW core 3.1.5 now blends Layer2+ULA in different way (details))
• sprites: 4bit relative patterns are incorrect in complex cases
• DMA: reading-registers are a bit off (for example status bit5+0 not reset correctly after LOAD, probably few more (but core 3.1.5 also reads bit0 wrongly, so always test own code with all target platforms))
• DMA: Zilog mode is not implemented (port 0x0B)
• NextZXOS streaming API doesn't work (the initialization of stream fails - rst 8 service 0x86 ; DISK_STRMSTART)
• there's still something not completely right about Enhanced ULA colours, maybe just default values are wrong, or even something is emulated wrongly? (test TFalBUla.sna)
• di : halt doesn't put CPU in infinite loop waiting for NMI, but proceeds further
• NextReg $02 implementation of soft/hard-reset does something, but not the same thing like HW yet (stuck in ROM03 infinite loop)
• sprites: the wrap-around the 512x512 coordinate space is only partially implemented in extreme cases (relative sprite so far from anchor that x8 scale wraps it back onto screen)
• default value: $6E and $6F are supposed to be fixed since V2.12.30, but the SNA test still reads zeroes
• some NextRegs read as zero until they are written into first (quick-boot mode with SNA file without full NextZXOS image) (for example regs $03, $12, $13, $14, $42, $4A, $4B, $4C)
• NextRegs $09, $34, $41, $8E read incorrectly (reads after certain writes produce wrong value) (but also the test is checking 3.1.5 behaviour, needs update to 3.1.10)
• Copper disassembler plugin does not open under ctrl+alt+c
• the initial file-import sequence of CP/M BIOS fails. (get cpm-a.p3d file from somebody with a working clean CP/M installation and copy that into c:/NextZXOS, or use other emulator to create the file)
• Z80: block of prefixes/instructions 0xDD/0xFD/EI does not inhibit masked interrupts

not verified in V2.15.02 (but known bugs of older versions, may be still present):

• default ULA palette after power on (quick boot without NextZXOS) is slightly different
• (should be improved now, to be tested) without the full NextZXOS card image the esxdos services are provided by open source CSpect plugin, the implementation is limited and crude - some of the returned values are incorrect/etc, but loading files works.
• direct loading of NEX files does not support all combinations of loading-screen type and palette on/off (but V2.12.9 does load more files than V2.12.5, all common ones should work)
• sprites: something something about default clipping... just set clip windows explicitly in your SW.

Platform Specific:

• Mac: Mouse does not work / behaves erratically
• Mac: after launch keyboard being irresponsive - try "alt+tab" to other app and back
• Linux: the copper disassembly window added in 2.15.01 (ctrl+alt+c) does not draw its content and remains as empty frame (after debugging the plugin: the winform doesn't receive paint messages from the emulator, same winform code running as stand-alone app without emulator does draw in linux)

Not a bug:

• CSpect works with "-sound" (does switch sounds OFF), but shows only black screen without it:
  • you forgot to install OpenAL, check the ReadMe.txt of the emulator.