How much RAM is 64K 36bit words of Core Memory 789

'Anne & Lynn Wheeler' wrote, in part: "original 360 were 30, 40, 50, 60, 62, & 70. 60, 62 & 70 were going to have one mic core store (with one mbyte ... four "core boxes"

I was wrong when I stated 'core memory' pbutted with the advent of the System 360; it persisted through the '70s. Only at the last of the System 360 series did solid state memory make an appearance as memory cache storage. So I guess the sequence of state of the art computing memory was beads on a stick to ~1935, vacumn tubes to ~ 1950, accoustic delay lines to ~ 1960, core storage to ~ 1978, magnetic drums ~ 1978, and then solid state memories through the present, with some overlap?

Other System 360 models were the 360-20 (hardware multiply and divide was optional), the 360-20 (8 bit wide data bus), the 360-25 (which could execute IBM 1401 code natively by loading new microcode instructions via a deck of punched cards), the 360-44 (with an instruction set biased toward scientific calculations). In the late

Though I can not find it at the IBM website, I seem to remember the System 360-45 (virtual memory).

stored on magnetic tape. Data density was very low ( ~ 1000 to 2000 characters per inch) and memory was limited, ~ 32 KBytes. A complete batch run of transactions against the database, and the resultant reports could require a week of operations. Disk drives were small compared to such databases; in the late '60s 'data cells' were the only way to provide online storage in the 100's of Megabytes range. The 'data cell' was a real Rube Goldberg device; think of a Jukebox using dictaphone belts.

Phil Weldon