Everything was _way_ more expensive back then, and the CRT monitors had to be driven with electron beam steering gaps (blanks) while the output cycled to the ne

Everything was _way_ more expensive back then, and the CRT monitors had to be driven with electron beam steering gaps (blanks) while the output cycled to the next row. Thus there was downtime for an otherwise idle chip to do some work, and yes, saving a few dollars or 10s of dollars in 1970s money was a LOT of money!