Intel 8086 and 8088

Instruction pre-fetching is very important phenomena in 8086 microprocessor. There is a 16-bit register set located in the BIU (bus Interface Unit) known as QUEUE.

While EU (Execution Unit) is working on the instructions i.e decoding and executing them, queue fetches the next sixinstruction byte of the running program. It is to be noted that, unlike stack (which is last in first out), queue is first in first out. Instruction which is fetched first is retrieved first.

This is much faster than sending out the address and waiting for memory to send back the instruction byte or bytes.

Limitation of QUEUE:

This pre-fetching of instruction speeds up processing but sometimes during 1JMP and CALL statements, queue has to be dumped and reloaded again starting from the next address.

Fetching the instruction while the current instruction executes is called pipelining.

1. Like in c++ programming, when a function is called the control is transferred to the function and its instruction

You have an adder circuit that can hold a maximum value of 100. With the carry it can hold values up to 199, the carry distinguishes between 31 and 131. But if the sum is greater than 199, you have overflow, because the circuit has no way of telling you what the actual value is.

[edit]

you have an overflow when the size of the result doesn't fit to the capacity of the memory sign of the result is different from what is expected (for example, getting a negative result when adding 2 positive numbers) The carry out occur when the size of the result doesn't fit to the capacity of the memory, yet its sign is correct.

Test 0 [Address test, walking ones, no cache]

Tests all address bits in all memory banks by using a walking ones address pattern.

Modes of Winding Up of Companies

As per Section 425 of the Act, the modes of winding up are:

1. Compulsory Winding up by the court.
   1. Members' Voluntary winding up.
   2. Creditors' Voluntary winding up.
2. Voluntary winding up,
3. Winding up subject to supervision of the court.

MODES OF COMPANIES WINDING UP

Compulsory Winding-up by the Court

The court may wind up a Company:

a. if the company has, by special resolution, resolved that the company should be wound up by the court;

b. if default is made in delivering the statutory report to the Registrar or in holding the statutory meeting;

c. if the company does not commence its business within a year from its incorporation, or suspends its business for a whole year;

d. if the number of members is reduced, in the case of a public company, below seven, and in the case of a private company, below two;

e. if the company is unable to pay its debts;

f. if the court is of the opinion that it is just and equitable that the company should be wound up.

The 'just and equitable' clause effectively makes the powers of the court unlimited. In a normal situation, the court might order the winding-up of a company in situations such as a deadlock in the business or continuous losses eroding the capital.

Voluntary Winding-up

A voluntary winding-up may be made on any one of the following grounds:

(a) when the period, if any, fixed for the duration of company by its articles, has expired;

(b) an event has taken place, on the occurrence of which the articles provide that the company is to be dissolved;

(c) if the company passes a special resolution that the company should be wound up voluntarily (section 484(1) of the Act).

In circumstances (a) and (b), an ordinary resolution passed in a general meeting for winding-up is sufficient.

A voluntary winding-up may be

(a) a members' voluntary winding-up,

(b) a creditors' voluntary winding-up.

The members' voluntary winding-up may be resorted to only when the directors or the majority of the directors, are able, at a meeting of the board, to make a declaration verified by an affidavit, to the effect that they have made a full inquiry into the affairs of the company, and that, having done so, they are of the opinion that the company has no debts, or that it will be able to pay its debts in full within such period (not exceeding three years) from the commencement of the winding-up as may be specified in the declaration (section 488 of the Act). In circumstances where the company is not solvent, it cannot be wound up by way of members' voluntary winding-up and it must resort to a creditors' voluntary winding-up. The procedure for a creditors' voluntary winding-up is that the company causes a meeting of the creditors' voluntary winding-up is that the company causes a meeting of the creditors of the company to be called for the day, or the next following day, on which the general meeting of the company is to be held at which the resolution for winding-up is to be proposed, and causes notices of the meeting of creditors to be sent to the creditors by post, simultaneously with the sending of the notices of the general meeting of the company (section 500 of the Act). The creditors and the company at their respective meetings may nominate a person to be the liquidator for the purpose of winding up the affairs and distributing the assets of the company.

Winding-up subject to the Supervision of the Court

After the company has passed a resolution for voluntary winding-up, the court may make an order that the voluntary winding-up shall continue, but subject to the supervision of the court and with such liberty for creditors, contributories or others to apply to the court, and generally on such terms and conditions as the court thinks just (section 533 of the Act). Thus, a voluntary winding-up can e converted into a winding-up subject to the supervision of the court, on terms and conditions imposed by the court.