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Sense Switch
A sense switch, or program switch, is a switch on the front panel of a computer whose state can be tested by conditional branch instructions in software.Rudolf F. Graf ''Modern dictionary of electronics seventh edition'', Newnes, 1999 Most early computers had several sense switches. They were typically used by the operator to set program options. On the IBM 1620 there are four switches, and their state can be tested via special forms of the IF-statement offered by the FORTRAN compiler for the IBM 1620. For the IBM 1130 there are sixteen switches matching the sixteen-bit word size of the computer, plus a toggle switch adjacent to the power on/off switch. These bit-switches are more normally used with the computer stopped to specify some memory address to be viewed (via the indicator lights on the front panel), or set. The state of these switches can be determined by a program, and so a running program might modify its behavior depending on the switches, such as change the amou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Front Panel
A front panel was used on early electronic computers to display and allow the alteration of the state of the machine's internal registers and memory. The front panel usually consisted of arrays of indicator lamps, digit and symbol displays, toggle switches, dials, and push buttons mounted on a sheet metal face plate. In early machines, CRTs might also be present (as an oscilloscope, or, for example, to mirror the contents of Williams–Kilburn tube memory). Prior to the development of CRT system consoles, many computers such as the IBM 1620 had console typewriters. Usually the contents of one or more hardware registers would be represented by a row of lights, allowing the contents to be read directly when the machine was stopped. The switches allowed direct entry of data and address values into registers or memory. Details On some machines, certain lights and switches were reserved for use under program control. These were often referred to as ''sense indicators'', ''se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data General Eclipse
The Data General Eclipse line of computers by Data General were 16-bit minicomputers released in early 1974 and sold until 1988. The Eclipse was based on many of the same concepts as the Data General Nova, but included support for virtual memory and multitasking more suitable to the small office than the lab. It was also packaged differently for this reason, in a floor-standing case the size of a small refrigerator. The Eclipse series was supplanted by the 32-bit Data General Eclipse MV/8000 in 1980. Description The Data General Nova was intended to outperform the PDP-8 while being less expensive, and in a similar fashion, the Eclipse was meant to compete against the larger PDP-11 computers. It kept the simple register architecture of the Nova but added a stack pointer which the Nova lacked. The stack pointer was added back to the later Nova 3 machines in 1975 and also used on the later 32-bit Data General Eclipse MV/8000. The AOS operating system was quite sophisticated, advan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
