Provided port access methods. The Comtrol SV11 requires no delays between accesses and uses PC I/O. Some drivers may need a 5uS delay
In the longer term this should become an architecture specific section so that this can become a generic driver interface for all platforms. For now we only handle PC I/O ports with or without the dread 5uS sanity delay.
The caller must hold sufficient locks to avoid violating the horrible 5uS delay rule.