T80 cpu

Hi,

The opcodes LD A,R and LD A,I don't change the flags H, N, Z and S correctly.

This make bugs in some games with ZX Spectrum cloned in FPGA.

The solution:

diff -Naur T80.vhd T80_fixed.vhd

--- T80.vhd Sun Nov 24 13:51:28 2002 +++ T80_fixed.vhd Tue May 6 19:10:00 2014 @@ -604,9 +604,25 @@ when "00" => ACC <= I; F(Flag_P) <= IntE_FF2;

•                                           if I = X"00" then

•                                                   F(Flag_Z) <= '1';

•                                           else

•                                                   F(Flag_Z) <= '0';

•                                           end if;

•                                           F(Flag_H) <= '0';

•                                           F(Flag_N) <= '0';

•                                           F(Flag_S) <= I(7);
                                    when "01" =>
                                            ACC <= std_logic_vector(R);
                                            F(Flag_P) <= IntE_FF2;

•                                           if R = 0 then

•                                                   F(Flag_Z) <= '1';

•                                           else

•                                                   F(Flag_Z) <= '0';

•                                           end if;

•                                           F(Flag_H) <= '0';

•                                           F(Flag_N) <= '0';

•                                           F(Flag_S) <= R(7);
                                    when "10" =>
                                            I <= ACC;
                                    when others =>

Thanks!!

Hi, I appear to be the maintainer for this still. I need to merge all the versions (including the one I am maintaining at fpgaarcade back here). Thanks for reporting, Mike p.s. if anybody else reads this and has other bug fixes, please enter a report here!