directly into the core memory system. Nuclear Data provided interfaces to the following peripherals: Bulk storage devices Diablo Model 31 standard density disk cartridge Diablo Model 31 high density disk cartridge EDP fixed-head disk models 3008, 3016, 3032, 3064, or 3120 Magnetic tape I/O devices Magnetic cassette tape PEC 7-track magnetic tape PEC 9-track magnetic tape Paper tape I/O devices Superior Electric Model TRP125-5 photoelectric tape reader (125 char/sec) Dataterm Model HS300 photoelectric tape reader (300 char/sec) Remex Model RPF1150B photoelectric tape reader (200 char/sec) Remex Model RPF1075B mylar tape punch (75 char/sec) Tally Model 1504 paper tape reader (60 char/sec) Tally Model 1505 paper tape punch (60 char/sec) Teletype Model BRPE11 paper tape punch (110 char/sec) Hard copy I/O devices Data Products Model 2410 line printer Centronics Model 101 line printer (165 char/sec) Franklin Model 1220 printer (20 lines/sec) Franklin Model 1230 printer (30 lines/sec) Hewlett-Packard Model 5050A printer (20 lines/sec) Hewlett-Packard Model 5055A printer (10 lines/sec) Calcomp digital incremental plotter Programming facilities The ND812 did not have an operating system, just a front panel and run and halt switches. The I/O facility allowed for peripherals to directly load programs into memory while the computer was halted and not executing instructions. Another option was to enter a short loader program that would be used to bootstrap the desired program from a peripheral such as a teletype or paper tape reader. Since core memory is non-volatile, shutting off the computer did not result in data or program loss. A number of system programs were made available by Nuclear Data for use with the ND812: BASC-12 assembler, symbolic text editor, NUTRAN interpreter, and disk-based symbolic text editor, BASC-12 Assembler An assembler called BASC-12 was provided. BASC-12 was a two-pass assembler, with an optional third pass. Pass one generates a symbol table, pass two produces a binary output tape and pass three provides a listing of the program. A sample of the assembler from the Principles of Programming the ND812 Computer manual is shown below: /Input two unequal numbers "A" and "B", compare the two numbers /and determine which is larger, and output a literal statement /"A > B", or "B > A" as applicable. / /Input and store values for A & B *200 Start, TIF /Clear TTY flag JPS Input /Get value for A STJ A JPS Input /Get value for B STJ B / /Determine which of the two