[ Reply to This | Parent | # ]

No modern microcomputer does that.

This is not quite true. The Intel line of processors does not have dedicated BCD instructions, but they do have a "two- step" BCD ability, in which a "normal" binary addition is followed by the AAA ("Adjust AL after BCD Addition") instruction, which examines AL and, if greater than 9, adjusts the value to the correct corresponding BCD digit while generating a carry out into AH. (There are corresponding "Adjust" instructions for subtraction, multiplication, and division.)

The Intel chips also have "DAA" ("Decimal Adjust after Addition") and "DAS" ("Decimal Adjust after Subtraction") which do similar functions for packed decimal values.

---
"When I say something, I put my name next to it." -- Isaac Jaffe, "Sports Night"

[ Reply to This | Parent | # ]

• Memory register vs a register? - Authored by: Anonymous on Monday, April 01 2013 @ 09:33 AM EDT
  • Memory register vs a register? - Authored by: bprice on Monday, April 01 2013 @ 02:29 PM EDT
  • Memory register vs a register? - Authored by: Anonymous on Tuesday, April 02 2013 @ 05:16 AM EDT

The farce continues with this BCD Floating point number format. Apparently, there are still some programmers out there who do not recognise when they should be using integer or fixed point representations. If this makes any sense to you, please consider:

[ Reply to This | Parent | # ]