Split Integer into 2 bytes

KenHorse · Joined: 16 Jul 2004 Posts: 523

Ok, so why doesn't this work?

albertsm · Joined: 09 Apr 2004 Posts: 5921 Location: Holland

numbers of base 10 system which we use, can not be stored in a computer with base 10 since the computer only knows 0 and 1.
So numbers are binary coded. And we group 8 bits into a byte. For 8 bits, we can represent maximum 255 : 1111_1111 : 128+64+32+16+8+4+2+1
If we want bigger numbers for an integer/word we use 2 bytes. The LSB is still representing 0-255 but the MSB has a different weight : 256+512+1024+2048 etc.
If you use low() you get the LSB. If you use high() you get the MSB. But when printing these bytes, they loose their weight/significance. And you print as a decimal number.
So 3 means 3*256 and 238 need to be added : (3*256) + 238 which should make 1006.
Use the simulator to have a look at the bits and bytes.

consider what you was expecting for values like 32000 and 3271 ?

KenHorse · Joined: 16 Jul 2004 Posts: 523

I didn't take into account the weighting issue when trying to print those values.

My main concern is that an integer with a value of 1006 can be split into 2 bytes with actual values of 10 and 6 respectively. Are you saying low() and high() do that but that can't actually be printed but the bytes do contain the correct values for other uses?

albertsm · Joined: 09 Apr 2004 Posts: 5921 Location: Holland

when you use someInt=1006, it will be assigned with a binary number, the only number that can be used. have a look in the simulator.
1006 is just like we humans want to see a number. when you use INPUT , this decimal number is converted into binary. and when you use PRINT, this binary number is converted into a decimal string.
you can use str() to get a string, and then use left/right/mid or str2digits.

KenHorse · Joined: 16 Jul 2004 Posts: 523

Thanks Mark

I was hoping to have smaller compiled code than using strings but I guess it is what it is......

MWS · Joined: 22 Aug 2009 Posts: 2262

A = I \ 100
B = I MOD 100

KenHorse · Joined: 16 Jul 2004 Posts: 523

MWS · Joined: 22 Aug 2009 Posts: 2262

If 1006 divided by 100 gives you 2, you do something seriously wrong.

albertsm · Joined: 09 Apr 2004 Posts: 5921 Location: Holland

if you want integer division, the assigned variable need to be an integer too.

KenHorse · Joined: 16 Jul 2004 Posts: 523