◈ Instructions
MLD Load mem→RA
MRD Store RA→mem
ADD RA + mem
SUB RA - mem
AND RA & mem
JMP Jump
SKZ Skip if zero
SKP Skip if +
WAT Halt
DW Define word
MARINER JUPITER-SATURN '77
Flight Data Subsystem Emulator • 806.4 kHz • 8K × 16-bit CMOS
Voyager 1 Current Distance
24,596,234,112 km
Signal delay: 22h 51m one-way
◈ Instructions
MLD Load mem→RA
MRD Store RA→mem
ADD RA + mem
SUB RA - mem
AND RA & mem
JMP Jump
SKZ Skip if zero
SKP Skip if +
WAT Halt
DW Define word
Clock
806.4 kHz
~400,000 instructions/sec
Cycle Time
2.48 µs
Glacial by modern standards
Memory
8K × 16-bit
CMOS RAM, two 4K banks
Registers
RA, RB + 128
Working + special registers
Serial I/O
32 in / 16 out
For all those instruments
DMA
4 channels
MDS, DSS, ISS, PRA @ 115.2 kbps
Interrupt
2.5 ms
Periodic error recovery
Word Size
16-bit
12-bit addresses, 4-bit opcode