The following code is really good.
http://www.8052.com/users/mkaras/Puzzler2.A51

the following link is not working when ever I click on this link it takes me on the home page:-
Original State Machine Tutorial
The Leds tutorial has impressed me a lot and it is something that I was searching for, thankyou.
http://www.8052.com/users/mkaras/State_Machine.A51

There are lots of things in the code that are very advance programming for me, in order to understand these terms or techniques do you recommend any book which is easily available or weblink or should I place the questions here if I have any problems in this code, Iam using Introduction to Microcontroller 8051by Scott Mackenzine, Chapter Seven Assembly Language Programming of this book covers lots of instruction's explaination that is used in the Eight Leds code but still many things are not even present in this book.

What are vertical counters does it mean that it counts upwards in the ram bitwise or byte wise or like going up from 20H address etc. etc, and are there horizontal counters also ?

Michael Karas on the following link has writtten

http://www.8052.com/forum/read.phtml?id=57921

"The routine that is called on a periodic basis is typically called from inside a timer interrupt service routine and thus it is highly desireable to make this routine as efficient as possible"
, it means that in order to do parallel monitoring of bits in such a way that each bit is treated separately the monitoring has to be done in ISR so that what ever the program is processing it stops and check if any other bit get an active signal ?