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What is the bit rate of a video terminal unit with $80$ characters/line, $8$ $\text{bits/character}$ and horizontal sweep time of $100$ $\text{µs}$ (including $20$ $\text{µs}$ of retrace time)?

1. $8$ $\text{Mbps}$
2. $6.4$ $\text{Mbps}$
3. $0.8$ $\text{Mbps}$
4. $0.64$ $\text{Mbps}$

i/o scheduling is present in syllabus(2023). See the syllabus from official website.

Doubt: i/o scheduling and i/o handling different???

They are part of I/O which is in syllabus.

Bit rate of a video terminal unit $= 80 \times 8$ bits$/100 µs = 6.4$ Mbps

edited by

do we have to include retrace time for calculating bit rate of the video terminal? Because in retrace period video terminal unit does not sends bits to the terminal @srestha

edited by

I think in this question 20 micro sec of retrace time is included in 100 ......hence we have to consider 100
morever 640/120=5.33 no option match so retrace is included in 100 as per question

bit rate is the count of bits per second.

$80$ $characters$ =====>$100µsec$

$80\times 8$ $bits$======>$100µsec$

$640$ $bits$=======>$100µsec$

$1µsec$=======>$6.40$ $bits$

$1\times10^{-6} sec$=====>$6.40$ $bits$

$1 sec$====>$6.40\times 10^{6}$ $bits$

$bit$  $rate=6.40Mbps$

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What is the use of retrace time given in the question?

1
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