13 votes
Accepted

Why did decimal arithmetic slow down VisiCalc?

A number like 1234.56 takes three bytes in BCD where it would've taken eight bytes in double precision binary floating point. Generally speaking, that is not the case. If you have a database field ...
manassehkatz-Moving 2 Codidact's user avatar
9 votes

Why did decimal arithmetic slow down VisiCalc?

6502 supported SIMPLE BCD arithmetic. I would bet that the VisiCalc guys in the end didn't even use that feature and wrote the whole thing from scratch. There's not just addition and subtraction, ...
Will Hartung's user avatar
  • 12.2k
7 votes

Why did decimal arithmetic slow down VisiCalc?

Because decimal operations are slower, even on the 6502. There is processor support for 8-bit BCD addition and subtraction, but that's it. Code for decimal multiplication, division, shifting, ...
RETRAC's user avatar
  • 13.6k
7 votes
Accepted

How did VisiCalc decide how many decimal places to display?

VisiCalc doesn’t “decide”, it does what the user asks it to. As far as displaying values, it supports a few different display formats: general (the default), which displays however many significant ...
Stephen Kitt's user avatar
1 vote

Why did decimal arithmetic slow down VisiCalc?

Using binary floating-point math would have made some kinds of computations much faster, but would have made many other tasks slower, and using BCD math was a reasonble engineering decision. Nowadays ...
supercat's user avatar
  • 35.7k

Only top scored, non community-wiki answers of a minimum length are eligible