I actually have another method that might work better for some of you. After
having played with hex/bin numbers for almost 15 years, there are some
patterns and tricks that comes alive.
Designing sprites on my Commodore 64 and Amiga 2000 and new characters on my
PC, has filled my head with some of those reappearing numbers, so if you can
memorize the value of the sixteen combinations for the first four left bits
the right four bits should be pretty easy to figure out.
First of all, if you have to bits set that has a bit between them, it will
give a "nice" number.
For example 10100000 is 128+32=160, 01010000 is 64+16=80, and a combination
of both 11110000 is 240. That already gives you three combinations to
memorize.
Then there's the situations where only one bit out of the left four is set :
128, 64, 32 and 16. They should be fairly easy to remember too, and now
you're almost halfway there.
When you look at all sixteen combinations:
0000 0000 : 0 00
0001 0000 : 16 10
0010 0000 : 32 20
0011 0000 : 48 30
0100 0000 : 64 40
0101 0000 : 80 50
0110 0000 : 96 60
0111 0000 : 112 70
1000 0000 : 128 80
1001 0000 : 144 90
1010 0000 : 160 A0
1011 0000 : 176 B0
1100 0000 : 192 C0
1101 0000 : 208 D0
1110 0000 : 224 E0
1111 0000 : 240 F0
You can again see that it's simply the 16 scale, and if you remember those
16 numbers, it should be easy to subtract it from the original number which
gives you the right four bits.
Furthermore, if you write the above table down on your plastic board before
you start your test, you should be able to convert it in seconds.
Example 178:
1) You look in the table and see that 176 which is B0 is the closest equal
or less than 178.
2) 178 minus 176 is 2 so now you have your result B2.
Hth,
Ole
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Ole Drews Jensen
Systems Network Manager
CCNA, MCSE, MCP+I
RWR Enterprises, Inc.
[EMAIL PROTECTED]
http://www.oledrews.com/ccnp
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NEED A JOB ???
http://www.oledrews.com/job
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-----Original Message-----
From: Chuck Larrieu [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, November 14, 2000 12:37 PM
To: Cisco Mail List; Ole Drews Jensen
Subject: RE: BCMSN Hex- IP to MAC
I've found over the years that it a LOT of work to be truly lazy :->
Chuck
-----Original Message-----
From: Ole Drews Jensen [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, November 14, 2000 10:27 AM
To: 'Chuck Larrieu'; Jim Erickson; [EMAIL PROTECTED]
Subject: RE: BCMSN Hex- IP to MAC
Yeah but you would still have to divide the 8 bit decimal up in two 4 bit
decimals before you can use your memorization, unless you want to memorize
all 256 combinations in decimal, hex and binary - and maybe octal's too :-)
Ole
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Ole Drews Jensen
Systems Network Manager
CCNA, MCSE, MCP+I
RWR Enterprises, Inc.
[EMAIL PROTECTED]
http://www.oledrews.com/ccnp
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NEED A JOB ???
http://www.oledrews.com/job
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-----Original Message-----
From: Chuck Larrieu [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, November 14, 2000 11:17 AM
To: Jim Erickson; [EMAIL PROTECTED]
Subject: RE: BCMSN Hex- IP to MAC
it is a nice trick, but too much work for a lazy guy like myself. :->
I just memorize the table - it works a lot faster
we all know what 1-9 is in binary, or can count it up easily.
A=1010=10
B=1011=11
C=1100=12
D=1101=13
E=1110=14
F=1111=15
write it down on the paper before you start the test. refer to it when
necessary.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Jim
Erickson
Sent: Tuesday, November 14, 2000 8:55 AM
To: [EMAIL PROTECTED]
Subject: Re: BCMSN Hex- IP to MAC
Cool trick. Hadn't seen that one before. As I look at it, it actually does
the same thing as the method I posted, but skips the binary conversion step
(splitting the one octet into two quartets is equivalent to dividing by 16).
---JRE---
""Andre' Paree-Huff"" < [EMAIL PROTECTED]> wrote in message
00ee01c04ddc$bbf2cf90$[EMAIL PROTECTED]">news:00ee01c04ddc$bbf2cf90$[EMAIL PROTECTED]...
you can also go from decimal to hex by dividing by 16 example given 235
235 / 16 = 14 with a remainder of 11
14 in hex is E
11 in hex is B
answer EB
Another example 149
168/16 = 10 with a remainder of 8
10 in hex is A
8 in hex is 8
answer A8 hex
To convert hex to decimal is just as easy take the left most hex digit and
multiply it by 16 then add the right digit
EB in hex
E * 16
E=14
14*16 = 224
B=11
224 + 11 = 235
--
Andr� Paree-Huff
A+, ASE, CCDA, CCNP
MCSE+I, NET+, I-NET+
[EMAIL PROTECTED]
[EMAIL PROTECTED]
AOL AIM: pareehuff
"Jim Erickson" < [EMAIL PROTECTED]> wrote in message
8uq2ro$ppv$[EMAIL PROTECTED]">news:8uq2ro$ppv$[EMAIL PROTECTED]...
> No. But if you can go from decimal to binary, the step to hex is
> rudimentary. Just divide each octet into two quartets and convert. For
> example:
>
> 235 => 11101011 => 1110_1011 => 14_11 => E_B => EB
>
>
> ---JRE---
>
> ""Travis Parrill"" < [EMAIL PROTECTED]> wrote in message
> [EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
> > Does anyone know if there is a decimal to Hex conversion table on the
> BCMSN
> > test for the multicast IP to MAC address Translation.
> >
> > TP
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