Allow reading from port A in output mode. Add a separate bit for timer 1 PB7 toggling rather than changing the PB register directly. Don't clear the SR register on reset. Clears pcr & acr at construct time, in case something sets one of the handshaking lines before we've started. Use a separate variable for the latched inputs and the current inputs. Consolidated the input and output code. [smf]
sharc.c: Modernized cpu core.  [Wilbert Pol]