As far as the architecture of the calculator, it's kind of amazing that they were able to build a calculator chip at all, given the state of IC technology. The architecture is highly tuned to calculators, rather than being general-purpose. For instance, a "digit scan" register cycles through 10 scan lines to illuminate each digit. At the same time, it scans 10 rows of the keyboard.
Another interesting thing about the calculator chip is it has 11-bit opcodes. Powers of two are so ingrained in us that it seems bizarre to have 11-bit opcodes. But old computers often had random word lengths. The calculator's instruction set is very low-level, more like microcode than a "real" instruction set.
As far as the architecture of the calculator, it's kind of amazing that they were able to build a calculator chip at all, given the state of IC technology. The architecture is highly tuned to calculators, rather than being general-purpose. For instance, a "digit scan" register cycles through 10 scan lines to illuminate each digit. At the same time, it scans 10 rows of the keyboard.
Another interesting thing about the calculator chip is it has 11-bit opcodes. Powers of two are so ingrained in us that it seems bizarre to have 11-bit opcodes. But old computers often had random word lengths. The calculator's instruction set is very low-level, more like microcode than a "real" instruction set.