Scribe-Pad

bit_banging

2007-04-07T08:35:57-05:00

As the title says it all, this is about ‘Banging’ the ‘Bit’. This comes as a handy method for simplifying data transactions over certain interfaces. Here are a few applications where this can be used: * Programming a flash/PLD (though complex due to protocols, can be done). * Providing clock source to a peripheral where trace connecting clock is unavailable. * Data transaction in both Master/Slave mode with certain peripherals. But the complexity increases when in slave mode.

bitwise_questions

2007-04-07T08:00:54-05:00

1. The Sequence Given the inputs I={1,3,5}, return outputs O={3,5,1}. Meaning, given I=1, return O=3, and so on. These are the constraints imposed: * No extra memory other than ‘I’ should be used to process. * Only operators available are: &, |, ~, ^, >>, <<, +, -. * No logical operators/if’s/for’s/while’s please.

code-snippets

2007-04-07T08:14:56-05:00

Just a collection of Misc. Snippets. Not completely optimized and i wouldnot like to guarantee about the validation of the algorithm implemented in them. This code snippets are open for public and could be used as you wish (if at all it serves some purpose of yours :).

droste_effect

2007-04-07T08:16:38-05:00

Droste Effect [A square droste image.] A recursive enumeration of an art within itself is the droste effect. The word droste has its origin from the Dutch language. It is almost similar to the fractaline nature of the art. The Dutch painter/mathematician, M.C.Escher‘s “Print Gallery” is a very good example of the Droste effect. The puzzle that lied in the central blank spot of the image has been revealed by a group of Mathematicians at the University of Leiden in Netherlands.

game_of_life

2007-04-07T08:18:41-05:00

This is a small analysis of the celebrated Conway’s Game of Life. History of this game is really fascinating. All started with John Von Neumann’s wish of creating self-evolving machines and this is just a simplified quantification of his attempt by Conway.

joy_of_lisping

2007-04-17T09:21:02-05:00

Not for fun, but actually started to have some fun with cutty parenthesis lurking around the code, has a more ‘machine’ like flavour coding with those symbols. But the serious fun has become a bit serious after grabbing the beauty of the Lisp. The beauty of Lisp is its limited types/keywords, with flexible extension for building maximal blocks. Here are some snippets written for fun but could be put under analysis. There exists lot of variants of Lisp for the snippets presented below is writ…

kernel-commenting-style

2007-04-07T08:31:10-05:00

Commenting Style In order to make the task of extracting the functional headers easier, we could follow one of the numerous commenting styles available (javadoc, linuxdoc, kernel etc..). Here is a brief description of commenting in the kernel style.

knight_tour

2007-04-07T08:09:28-05:00

Problem of Chess have fascinated the human race for decades/centuries together. Im no escape! Here again, we would like to discuss the knight tour and the so called knight graph from which the tour is derieved. The knight graph is again an interesting one, artistically! Here are few snapshots of the knight graph and the code snippet to generate them.

lover_paradox

2007-04-07T07:59:58-05:00

Paradox of Love Just yet another paradox that flashes after realizing the Russel’s classic paradox. The content here is to be taken just as a fun stuff and _NO_ unethical motives behind. The Story Once upon a time there existed a person of truth (as people address) who didn’t have a pair. He was questioned regarding this as why didn’t he choose a pair for himself. The truthful person smiles for a moment and replies back in a soothing tone that,

neo_system

2007-04-07T07:59:31-05:00

Dream design of a system Out of sheer curiosity, there were a list of questions as equal to that of a kid’s wish that comes on its way. Here are a list of few of them proceeding to the artificialism from the naturalism. Its a ‘new’ system and finally i say a ‘wow’ which gets the name, ‘newow’ and i dont like to see letters being redundant on the new word. Hence removing those ‘w’, which is already ‘double u’:-) the name ‘neo’ for the system evolved.

p_np_problem

2007-04-07T07:58:41-05:00

IS P=NP? A celebrated problem in the theory of computation, really had fascinated many. A few thoughts over the problem is given below. This approach of solving the problem ofcourse has a flaw. The whole thread of discussion can be found in google-groups-cs-theory link.

poly_infinite_products

2007-04-09T09:46:11-05:00

Polynomials are undoubtedly a beautiful representation of abstraction by humans. Here we restrict our explorations in polynomials that carry integral powers/coefficients. Here are few simpler polynomials and their factorizations. Some examples For now, leaving all the rules of convergence, that play a tricky role of deciding the expansions, we take it for granted that some kind of convergence rule would hold and go on to investigate on the patterns of expansions in these polynomials.

sequence_encounter

2008-05-03T16:59:51-05:00

Sequences are so fascinating in their beauty. The changes in patterns and the dynamics would tie us up for the whole lifetime. It is hard to be an exception to avoid sequences. Here are few encounters with them. Journey through the sequences are so fascinating that you would cross the meadows that look the same but different.

solve_it_archives

2007-06-21T04:40:33-05:00

This section is a collection of problems that range from simple bit-related problems to digital designs. As such, no restriction is placed on proposing the problems. We do like to stick with few basic principles in this arena. Here are they: * Anyone can propose a problem and anyone can solve. * Take care not to repeat the problems that were already solved or proposed. * Make sure to maintain the count in this page to reflect the number of problems. * Its not demanding on the problem …

strict_inequalities

2008-05-04T08:51:40-05:00

Let us consider a sequence of integers, Sequence - A We form another sequence that is roughly half the length of the above sequence, Sequence - B We cannot of course ensure the same inequality to hold for the above , but in case if we want the above inequality to hold, we need to change values of some of the . Assuming that we change , in order to meet the constraint in , and we proceed further to create another sequence , in the following way as is obtained from . This process is not inf…

svg-template-header

2007-04-07T08:15:23-05:00

Just a small utility header to use the SVG file format. _shamelessly_ copied the SVG tags from W3C. #ifndef SVG_TEMPLATE_H #define SVG_TEMPLATE_H #define SVG_BEGIN "\n" #define SVG_DOCTYPE "\n" #define SVG_IMAGE "

technical-abbrevations-expansions

2007-04-07T08:30:37-05:00

Expansions This page contains a random list of expansions related to miscellaneous fields. Electronics/Telecom Abbrevation Expanded as Abbrevation Expanded as DTMF Dual Tone Multi FrequencyCCS Common Channel SignalingCAS Channel Associated SignalingSDH Synchronous Digital HierarchyTDM Time Division MultiplexingFDM Frequency Division MultiplexingWDM Wave Division MultiplexingTSI Time Slot InterchangePDH Plesiochronous Digital HierarchySTDM Statistical Time Division Multipl…

user_mode_driver

2007-04-07T08:34:03-05:00

In this user mode drivers, access of registers through mmap and interrupts through proc interface is discussed. This is a from Peter Chubb's User Mode Driver mechanism for linux kernel 2.6. A casual one to handle the scenarios from user space is discussed below. Whereas, it has limitations like shared interrupts cannot be used with this mechanism and a lot more. Infact at certain cases it would result in a deadlock and further discussions on this mechanism could be viewed in this discussion thre…

week-1

2007-04-09T02:33:45-05:00

week-2

2007-04-09T02:35:57-05:00

1. Is a Zero? Given a number (8/16/32/64 bit, +/-ve or 0) find if its a zero-valued number. Pretty easy task isnt? But wait! Here are a few restrictions on that: * No logical operators should be used [!, >, >=, <, <=, &&, ||, ==] * No if’s/for’s/while’s etc. * Only operators allowed: [ &, |, ~, ^, +, -, >>, << ]

week-3

2007-04-09T02:36:45-05:00

1. Palindromic Binary Strings Let us consider the k-bit binary strings. We inspect the palindromic strings of length k. Here are few analysis: k-bits Palindromic Strings Total 1 0×0, 0×1 2 2 0×00, 0×11 2 3 0×000, 0×010, 0×101, 0×111 4 And the above goes like this. What we are interested in is that, how many binary palindromic strings exists for a given length, N? Can we have an expression for the above in terms of N?

week-4

2007-04-09T02:37:20-05:00

1. Complex, is it so complex? Consider the scenario of complex multiplication. The basics of complex algebra tells (a + ib)(c + id) = (ac - bd) + i(ad + bc). Here we see, we do 4 multiplications and 2 additions. Consider architectures where multiplication operations are much costlier than addition. Can we do the above multiplication in a compact form so that the multiplication gets reduced? At which scenario its better to go for that method with less multiplication?

week-5

2007-04-09T02:37:50-05:00

1. Shuttles in Space Consider the scenario where the people of this world goes into a ET-spree for search of life out of earth. They send N space shuttles out in different directions in search of life. To maintain the team of shuttles, they need to communicate with each other so that they exchange the information of their present location in space and their guess on existance of life on the location they presently stand.

week-6

2007-04-09T02:38:28-05:00

String Compression Dexter is out with a crazy idea of designing a string compression algorithm. He wanted to store distinct symbols and any combination/permutation of that symbols is valid and hence need to keep track of all of them. So, he decides to proceed in this way:

welcome

2008-04-28T13:36:25-05:00

Aroused by curiosity, and by the way of pleasure in finding things out, certain scribblings of this amateur has been recorded. Thoughts always flow. There are designed to be that way. Its upto the system to hold the thoughts for itself that it fades away with time or to trust upon an illusive storage unit miles away which depends on the storage action using magnetics in a box. The system in me decides to choose the later, thus would be an open book and would record the thoughts that seems worthy…

x86_helloworld

2007-04-07T08:28:38-05:00

This is the result of the exploration into the world of mystery, the world of obfuscated coding. Actually some months back, there was a C code to print “Hello World” but uses no function by name main. It just had a char array, main. The main idea is to write the very first C code without using the main as a function but as an array. Is it possible? This is what the analysis about. Why is the x86? The title gives a very strong hint that the code is highly architecture dependent. An obfuscat…

xor_equation

2007-04-07T08:03:52-05:00

The given equation to be solved in the integral domain is the following: X ^ Y = X - Y, where X >= 0, Y >= 0 ................... (1) The Edges * As always, we have X ^ Y >= 0, we are restricted to values, X >= Y as the set of all solutions should be constrained to. This implies,