24 Jun
2026
24 Jun
'26
7:22 a.m.
On Jun 23, 2026, at 11:28 PM, Ken Seefried via cctalk
<cctalk(a)classiccmp.org> wrote:
On Mon, Jun 22, 2026 at 4:33 PM Fred Cisin via cctalk <cctalk(a)classiccmp.org>
wrote:
Unfortunately (or not?) the x86 BCD instructions have been removed from
'64-bit mode' in x86-64. I assume those processors are fast enough
emulating BCD if required to keep COBOL users happy.
The PDP-11 CIS instructions include BCD types and are very
interesting/weird (e.g. EDIT instruction).
I never looked at PDP-11 or VAX decimal instructions all that much, but from a superficial
look they seemed to be inspired by the analogous instructions of the IBM 360 series,
including (I'm pretty sure) the EDIT instruction.
paul
My
question "what is that used for?" Answer:
"compound interest in COBOL programming".
Oh yeah.
That's what it is for