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Nova, (Data General Nova)
a 16-bit minicomputer series built by the American company Data General starting in 1968. The Nova was designed by DEC PDP-8 chief engineer and Data General co-founder Edson de Castro. It was packaged into a single rack mount case.

Unlike the PDP-8, Nova was a load/store architecture. It had four 16-bit accumulators, where two could be used as index registers, and a 15-bit address space and PC. The Nova is a big-endian architecture. Since there is no byte addressing, bytes need to be parsed out of words using swaps and masks high-order byte first [1]. Nova consists of a nibble-serial 4-bit ALU - its RISC-like instructions perform arithmetical and logical operations with the options to rotate, test and branch on the (skip next instructon on zero, carry) the 17-bit result, and also to discard the result otherwise written into the target accu. Basic models of the Nova came without built-in hardware multiply and divide. The first models were available with 1 to 8 Kibi words of magnetic core memory.

System software provided include the real time operating system RDOS, assembler, Basic interpreter, and Fortran and Algol compiler, expanded with Forth, Lisp, and C through third party vendors [2].
NOVA Rack [3]

Nova Line

SuperNOVA

The SuperNOVA subsequently replaced initial magnetic core memory with faster ROM for library routines, and semiconductor (SuperNOVA SC) memory. The 4-bit ALU was extended to 16-bit using four instead of one bit slice 74181 ALU with speedup correspondingly [4].

Nova 1200

The Nova 1200 contained the entire CPU one one board, first shipped in 1971 [5]. It still had the Nibble-serial ALU, and up to 32 Kibi words magnetic core memory.
320px-Nova1200.agr.jpg
Nova 1200 Front panel [6]

Nova 8x0

The faster Nova 800 was released in 1971. The Nova 840 introduced memory mapping in 1973, allowing two discrete sessions running concurrently, each with its own controlling terminal [7].

Nova 2

The Nova 2 was essentially a simplified version of the earlier machines as increasing chip densities allowed the CPU to be reduced in size, with CPU and memory on a single board, introduced in 1973.

Eclipse

The Eclipse line, started in 1974, had an advanced, Nova upward-compatible instruction set, and included support for virtual memory and multitasking. The line was succeeded by the 32-bit Eclipse MV minicomputers in the early 80s, whose development was subject of Tracy Kidder's book The Soul of A New Machine.

Nova 3

In 1975, the Nova 3 combined features from all previous Nova designs, and added a hardware stack and appropriate stack instructions [8]. The Nova 3 was reduced to a chip set in 1976, called the microNOVA with hardware Multiply/Divide, optionally before, becoming a standard [9].

Nova 4

The Nova 4 was the last of the Nova line, released in 1987, the CPU a derivation of the Eclipse S/140. The Nova 4 is implemented around four AMD 2901 bit-slice chips and, unlike all earlier Novas, is microcoded.

Chess Programs


See also


External Links

SuperNOVA

Nova 1200

Nova 8x0

Nova 2

Eclipse

Nova 3

Nova 4


References

  1. ^ Data General NOVA Basic Instruction Summary by Carl R. Friend
  2. ^ Data General Nova from Wikipedia
  3. ^ Data General NOVA System, (beige and yellow, center bottom) and a cartridge hard disk system (opened, below Nova) in a mostly empty rack mount, Goodwill Computer Museum, Austin, Texas, Image courtesy Jeff Keyzer, January 07, 2011
  4. ^ Data General Nova from Wikipedia
  5. ^ The Retro-Computing Society of RI, Inc.: Nova 1200
  6. ^ Front panel of a Data General Nova 1200 minicomputer by Arnold Reinhold, CC BY-SA 4.0, Wikimedia Commons, Data General Nova from Wikipedia, bit 0 for Carry, bit 1 for MSB and bit 15 for LSB!
  7. ^ Nova 840 from Carl Friend's Minicomputer "Museum"
  8. ^ Nova Stack Instructions from DG Nova Extended Instructions by Carl R. Friend
  9. ^ Nova Multiply/Divide from DG Nova Extended Instructions by Carl R. Friend

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