ELF II

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ELF II
ElF II Computer.jpg
Type Hobbyist computer
Release date 1978
Operating system Monitor ROM
CPU 8 bit RCA 1802 @ 1.76MHz
Memory 256B - 64KB
Storage Cassette Tape

The Netronics ELF II was an early microcomputer trainer kit featuring the RCA 1802 microprocessor, 256 bytes of RAM, DMA-based bitmap graphics, hexadecimal keypad, two digit hexadecimal LED display, a single "Q" LED, and 5 expansion slots.

Hardware[edit]

Available hardware accessories included:

  • The "Giant Board" (ROM monitor, serial and parallel I/O, Cassette interface)
  • 4KB and 16KB (static) RAM boards
  • ASCII Keyboard
  • Video display card (monochrome text)
  • Low resolution color graphics board
  • "Full BASIC" board with BASIC preloaded in ROM chips
  • EPROM burner board
  • External Power Supply
  • Attractive, heavy duty metal cases for the CPU, keyboard, and power supply

Software[edit]

Available software included:

Notable Innovations[edit]

  • Unlike similar "bare circuit card" trainer/experimenter computers of the day, the ELF II could be easily expanded thanks to its built-in bus.
  • The video card is mounted underneath the keyboard inside the metal case. This allows it to be used as a standalone computer terminal if needed.
  • The Elf II used a simple and low-cost math coprocessor. The "Full BASIC" ROM card contained an RPN calculator chip. As a result, floating point operations were an order of magnitude faster than what was possible in software. However, the BASIC syntax for math was non-standard as it used postfix RPN notation. Historically, this was also the heyday of Hewlett Packard calculators, so it was a fair bet that any technically minded person willing to assemble a computer already knew RPN.
10 REM This program will PRINT the number 30
20 A=10,B=20
30 C=A#B+
40 PRINT C
50 END

In the code above, the "#" symbol is equivalent to the "Enter" key on a RPN calculator.

The Name[edit]

The ELF part of the name came from an earlier machine called the "COSMAC ELF", published as a construction project in Popular Electronics magazine. Improvements on its predecessor included an etched PCB, a hexadecimal keypad instead of toggle switches for program entry, the CDP1861 Pixie-graphics chip, and the 5 slot 86-line bus for expansion cards.

See also[edit]

External links[edit]