Caches existed, just not in microprocessors. The IBM 360 model 85 introduced caches in 1968 [1]. The DEC PDP-11/70 had one in 1975 [2], the same year the 6502

Caches existed, just not in microprocessors. The IBM 360 model 85 introduced caches in 1968 [1]. The DEC PDP-11/70 had one in 1975 [2], the same year the 6502 debuted. The Motorola 68020 was the first Motorola microprocessor with a cache in 1984, and the 386DX was Intel's first in 1985 [Wikipedia]. I agree, it's kind of shocking to read about the designs people could get away with before caches became important. It also illustrates why it's so important to continually re-evaluate any programming doctrine related to performance and data organization. [1] http://www.bitsavers.org/pdf/ibm/360/funcChar/A22-6916-1_360-85_funcChar_Jun68.pdf http://www.bitsavers.org/pdf/ibm/360/funcChar/A22-6916-1_360..., see references to "buffer storage" [2] http://www.pdp-11.nl/pdp11-70startpage.html http://www.pdp-11.nl/pdp11-70startpage.html