Product number (P/N): DC2266,
Keywords/Tags: DC2266
Date of intro-: ~1971, TimeKeeper IC's (sorted by Year): (Link),
Classification: / Part / Calculator-ChipSet,
Featuring: Logic-technology: LSI (Large Scale Integration), calculator-chipset,
Serie-members: ROCKWELL_parts(E): DC2266 (ChipSet); SHARP_parts(E): DC2266 (ChipSet),
Info: The DC2266 was the specialized ‘precision officer’ of the ROCKWELL chipset.
While its siblings handled inputs and core logic, the DC2266 was dedicated to the mathematical formatting that made a calculator useful for real-world science and finance
Primary Function:
Decimal-point Control
The ‘DC’ in its name stands for Decimal-point Control.
In the early days of digital calculation, managing where the decimal point sat was a complex task that required its own dedicated silicon.
Its main duties included:
Floating Decimal Point:
It enabled ‘floating’ logic, allowing the decimal point to move automatically to provide the most accurate result possible on an 8-digit display.
Overflow Protection:
It monitored the size of the numbers being processed.
If a calculation exceeded the machine's capacity, the DC2266 triggered the ‘Error’ or ‘Overflow’ flag, signaling the NRD2256 to light up the error indicator.
Rounding and Alignment:
It ensured that numbers were correctly aligned before and after an arithmetic operation (e.g., making sure decimal points lined up during addition)
Used in: SHARP_parts(E): 4041PCBD45 (PCB)