Happy new year 2009. A new branch has appeared on the repository : the fast i/o 3. This is a direct hardware implementation of OS_SI. It not buffered like the previous and respect the whole API. It seems to work reliabily with hardware handshaking. Timeout works and escape key detection too. Software handshaking (Xon/Xoff) and parity will be implemented in a future version. Any feedback is of course welcome, specialy at high speed (19200 and 38400 baud) which should (now) work.

It is a Z80 compatible clone but running froma 16 bits RISC architecture. It is 20% faster than a classic Z8400 (the CMOS Z80) at the same speed. It is up to 30% is the special KC80 which seems to be compatible with the Z88 because it works only in IM1 (interruption mode 1, the Z88 mode). So, I unsoldier the Z80 from the motherboard and fitted the UKC84/00A in a socket. Unfortunately, the Z88 never wanted to boot both in Z80 and KC80 mode. I presume it is a problem of timings… Lots of japanes people have replaced their MSX processor with this one and observed efficient overclocking.