On Sat, 2025-02-15 at 12:53 -0700, ben via cctalk wrote: > Around what time did core memory drop in price that one had ample > main > memory to compile with? I am guessing the late 60's.
The IBM 704, first delivered in 1956, had 8,192 words of 36-bit core memory. The IBM 701, developed in in 1951 and delivered in 1953, had memory consisting of 72 Williams Tube CRTs; some were later converted to core. Like SWAC, there was a tendency of zero bits to leak into adjacent words, so every ten milliseconds or so, programs would swap CRT memory to drum and back. The first IBM 1401 was announced in October 1959 and delivered shortly thereafter, with 4k characters of of 12.5 microsecond core memory. One could eventually get 1401, 1440, and 1460 with 16k memory. 1410, and the faster but functionally identical 7010, could be gotten with 100k memory.
