IBM System/360 Model 44
The IBM System/360 Model 44 was a specialized variation of IBM's System 360 computer architecture designed for scientific and real-time computing.
The Model 44 was announced August 16, 1965 and withdrawn September 24, 1973.[1]
Architecture
The Model 44 lacked the storage-to-storage character and decimal instruction sets of a standard System/360,[2] however an "extended instruction set" feature was available to provide the missing instructions.[1] The machine featured four unique instructions: Chanqe Priority Mask (CHPM), Load PSW Special (LPSX), Read Direct Word (RDDW), and Write Direct Word (WRDW).[2]: p.73 In addition to standard System/360 short and long floating point the system was advertised as having "variable-length precision floating point arithmetic", the ability to use any specified precision up to the full fifteen digits offered by long precision to gain speed.[1]
The system came with three memory sizes: E (32 KiB), F (64 KiB), and G (128 KiB) with an access time of 1μsec, which put it closer to the Model 65 (.75μsec) than the Model 50 (2.0μsec).[3]: pp.6-11, 6–12 [1]
For added speed, the general purpose registers could be implemented in Solid Logic Technology (SLT) integrated circuitry.[1]
Peripherals
The Model 44 could support up to one standard and two high-speed System/360 multiplexer channels.[1]
A unique feature of the Model 44 was its integrated single disk storage drive which used the IBM 2315 cartridge and provided approximately 1 MiB of removable disk storage built right into the CPU.
Software
Software included a basic monitor, an assembler, a FORTRAN compiler, and a library of scientific subroutines.[1]
References
- ^ a b c d e f g IBM Corporation. "IBM Archives: System/360 Model 44". Retrieved October 18, 2012.
- ^ a b IBM Corporation (1966). IBM System/3S0 Model 44 Programming System Assembler Language (PDF).
- ^ IBM Corporation (1974). IBM System/360 System Summary (PDF).