For only $20 you can upgrade Sigma Chess 6.1 Lite to Sigma
Chess 6.1 Pro, which contains the full feature set. Registration and
payment is done via Kagi which
is a widely used Internet payment service. In return you will receive a personal
license code by e-mail that unlocks the
limited/disabled features
in your current installation of Sigma Chess 6.1 Lite, and thus upgrades it to
Sigma Chess 6.1 Pro (see below).
Note: Sigma Chess 6.1 Pro is a free upgrade
for owners of Sigma Chess 6 Pro and Sigma Chess 5 Pro. Owners of Sigma Chess 5 Pro
can upgrade using their existing Sigma Chess 5 license code.
Registration is done online from the secure Kagi server here:
Upgrading from Lite to Pro
Once your payment has been processed you will receive a confirmation e-mail
from Kagi (normally within a few hours). A few days later you will receive
another e-mail from the author of Sigma Chess containing a unique Serial
Number and a personal License Key. In order to upgrade to Sigma
Chess 6.1 Pro, you then simply click the Upgrade button in the Sigma
Chess 6.1 About dialog and enter this license information. From then on
Sigma Chess 6.1 will run in "Pro" mode with the full feature list enabled!
"Why haven't I received my license code?":
If several days have passed and you still haven't received your license code
by e-mail, please send me an e-mail
so I can resend it. A common problem is that a customer accidentally
specifies an incorrect e-mail address in the payment, and therefore won't
receive the license code (it's bounced back to me, and I have no way of telling
the customer to send the correct e-mail address!)
Note: All future updates to Sigma Chess 6.1 Pro are provided free of
charge for owners of Sigma Chess 6.1 Pro. You simply need to download the new
version 6.x.x here. It will automatically
run in Pro mode.