The circuit size was limited by computing constraints
such as memory. Another equally important size limit
was the mean time to the computer crashing, which
happened as often as every 15 minutes. If the computer
went down, we lost the whole run. This also applied to
file editing. There were no auto-backup files. We
learned by brutal experience to save our work frequently.
Wow. When we look at what those before us have done, there can be a tendency to cast a dismissive eye to the shortcomings of the final design. Yes, but look what they had to go through to get as far as they did.