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Signal Processors F612 - problems

ned
ned
Posts: 19

Dear All

Has anybody else noticed a couple of mistakes or oddities in the Signal Processors paper?

Q2           Shouldn't that read 'The state of L is copied to Q whenever the enable input D goes high'.

               This changes the answer for Q.

               Does this make the question invalid for marking purposes?

 

Q7b          Code section b is initiated only when neither T or A are pressed and the sensors are dry.

                Seems a little unusual, as sensor 1 is already wet (does it have to dry out?).

 

Q7c           I presume that they mean by 'flood' that both sensors are underwater, although this is not stated.

                (This is quite a change from where we left the sensors in part (b) when they were dry)

                I can write code for the flood, no problem.

                If switch T is closed, then I0 is 0. Do I assume...

                1) That A is not pressed? (otherwise I need to look for numbers greater than or equal to $40)

                2) That both sensors are dry? (otherwise I need to check for $04, $10, $44, $50)

                If these assumptions are wrong, then I need to add several question boxes to my answer.

             Also:

                If there is no flood, do I wait?

                If T is not closed do I wait?               

                Which one takes priority - flood or T pressed?

 

                This question seems to have been put in to test A grade students. However, I think that it might have backfired.

 

any thoughts?

Ned

Replies

andy masters
andy ma ...
Posts: 18

I've just put in my version of these complaints about Q2 and Q7c to our exams office.

Sorry about not replying to your email earlier, Ned, but I've been keeping my head in a 'happy place' for a couple of weeks to cope with the start of the end fopr my Electronics department. Bah. We had at least 10 AS Electronics depts in Hampshire's 6th-Form Colleges a few years ago: from September it'll be just 2 (4 have closed just now).

 

mde
mde
Posts: 7

I hadn't noticed the latch error. they'll have to scrap 2, that's pretty poor.

7b: It looks to me like the first decision box is just waiting for A to be pressed regardless of whether any sensor is wet; and code section b is then activated when either switch is pressed, or either sensor is underwater - as the 'default' input byte is 01.

I thnk you're correct that 7C is unclear, though. Presumably they will have to allow for a variety of interpretations when marking?

 

ned
ned
Posts: 19
Quote:
Originally posted by mde, 14:15, 9th June 2015

I hadn't noticed the latch error. they'll have to scrap 2, that's pretty poor.

7b: It looks to me like the first decision box is just waiting for A to be pressed regardless of whether any sensor is ...

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I hadn't noticed the latch error. they'll have to scrap 2, that's pretty poor.

7b: It looks to me like the first decision box is just waiting for A to be pressed regardless of whether any sensor is wet; and code section b is then activated when either switch is pressed, or either sensor is underwater - as the 'default' input byte is 01.

I thnk you're correct that 7C is unclear, though. Presumably they will have to allow for a variety of interpretations when marking?

 

You're absolutely right about 7B. I made two schoolboy errors and will chastise myself severely in my own time.