On 5/28/24 22:27, Lars Brinkhoff via cctalk wrote: > However, it's not entirely clear cut. In many situations data inside > words are arranged "left to right" and in this case the PDP numbering > sometimes is more convenient than the opposite.
The CDC STAR/CYBER machines were bit-addressed. When dealing with bit strings for the likes of control- and sparse-vectors, it's the only thing that makes sense, particularly when vectors can be very large. As the nominal word size of those machines was 64 bits and the preferred display radix was hexadecimal, it made for some interesting mental gymnastics when converting between bit, byte, halfword and word addresses (alignment requirements). The odd fallout from this was that when a word in memory was addressed, the most significant bit was the lowest bit address. --Chuck
