[cctalk] Re: Good computer books for 1960's computers

[Paul Koning via cctalk]

> On Sep 30, 2026, at 11:21 AM, Carey Schug via cctalk <cctalk@classiccmp.org> 
> wrote:
> 
> how many bits count?
> 
> does the flag bit count in the decimal IBM 1620?  It indicated the high
> order digit of a decimal number, and nothing else.  

I thought it marks the sign when on the high order digit, and the end of the 
number when on the low order digit.  Yes, I would count the flag (but not 
parity) so you could call a 1620 a 5 bit machine.  But calling it a BCD machine 
is more logical.

        paul