Recoding my ZX81-emulator: IM2-table

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Dr beep
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Recoding my ZX81-emulator: IM2-table

Post by Dr beep » Thu Mar 26, 2020 9:37 pm

I am recoding (speeding up) my ZX81 emulator for the 48K ZX Spectrum.

I can make it quicker but I can use some info.

1) to keep code smaller I only want to use the IM2 table as if no hardware is attached (FF). Will this do or is due to some hardware a full table needed?

2) The emulator is now fully coded in upper memory (>32k). What are the speedeffects of coding or storing tables in lowermemory (contented memory)? I will need this part of memory but at this moment I can either store tables which are read once on each opcode or screentables and intruptroutine to be executed more times per second. I want the fastest program possible. Loading and saving is stored here too, but that is no issue during emulation.

As for you all... this is the old emulator: https://www.worldofspectrum.org/infosee ... id=0015646
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