RAM has always been used to refer to internal memory. Disk is not random access, but is not fully sequential. While a program can address just about any byte on a disk drive, generally, one must position the heads at the proper cylinder, wait for the sector containing your data to pass under the heads, and then read that sector into internal memory, then extract your data from that sector. It is also orders of magnitude slower than RAM storage. Correcting myself a bit since I go back to the user of core memory. I once participated in writing a point of sale system for a fast food restaurant that was based on a DEC PDP-8 with 4K (12-bit words) of core memory. We had no external storage. All data was either transmitted to the home office each night or in the case of a failure, recorded by the manager and snailed or called in. We would upload any program changes as part of
On Tuesday 19 July 2005 8:00 am, Jerry Feldman wrote: the nightly data exchange. BTW: Baud rate (nominally 1200bps) was actually controlled by timing loops in the program since there were no uarts- Send start bit- loop-for each next 8 bits send a bit/loop- send stop bit. If the system crashed, we had to send a service person in with the program on punched paper tape and a paper tape reader. -- Jerry Feldman <gaf@blu.org> Boston Linux and Unix user group http://www.blu.org PGP key id:C5061EA9 PGP Key fingerprint:053C 73EC 3AC1 5C44 3E14 9245 FB00 3ED5 C506 1EA9