Password System in OG Tecmo?

[keithisgood]

Any existing documentation on how the Password system in Tecmo Bowl works? After a few minutes messing around with it, looks like the password manipulates $0084-0089 in RAM, with $0084 and $0085 being the most dynamic. Just guessing, but it would seem with 6 bytes, the password generates 3 pointers to fetch 1)your team, 2)your opponent, 3)which week of the season. However, I'm unable to crack it as yet.

 

Just wondering if there was any existing documentation before I start digging into it.

[bruddog]

Ya the decode routine on bytes 86 through 89 is not trivial to figure out. I found the routine but its pretty convoluted. If I knew the memory locations for regular tecmo bowl it might be easier

[bruddog]

Nevermind found the answer on gamefaqs. Also someone created a web tecmo bowl password generator at some point. 

 

 

"This section looks at the technical side of the passwords.  Once you fully
understand this section, you'll be able to create a password that will allow
you to place yourself at any point in the season as any team.  The team that
you play will be random (unless you go to the Tecmo Bowl), because I did not
take the time to decipher the part of the password that differentiates between
randomness and a select team.  You will need some basic math skills to be able
to understand this section.

 

Each password is constructed of eight characters with each being represented by
one of sixteen possible characters: the numbers 0 through 9 or A, B, C, D, E,
or F.  It could look like the following:

1234ABCD

 

Now, each part of the password can be broken down.  The easiest way to think
of it is in three parts: what team you are, what week you're on in the season,
and who you've beaten.  It's actually more complicated than this, but this
breakdown essentially tells you everything you need.

 

To start, you'll need to order the teams as they are in the game, into groups
of four (the numbers will be explained in a bit):

Indianapolis    xxx001xx
Miami           xxx002xx
Cleveland       xxx004xx
Denver          xxx008xx

Seattle         xxx010xx
Los Angeles     xxx020xx
Washington      xxx040xx
San Francisco   xxx080xx

Dallas          xxx100xx
New York        xxx200xx
Chicago         xxx400xx
Minnesota       xxx800xx

 

 

To start, we'll look at the first two characters of a password.  These help to
tell the game where to start the list of who you've beaten and who you are.
Use the top line to find what team you are or would like to be.  Next, think of
who you would like to have already beaten.  From the list of teams you want to
have beaten, go down the column until you run into the first team on the list.

    IND - MIA - CLV - DNV - SEA - LAN - WAS - SNF - DAL - NWY - CHI - MININD   xx    04    08    0C    10    14    18    1C    20    24    28    2C  MIA   01    xx    09    0D    11    15    19    1D    21    25    29    2DCLV   02    06    xx    0E    12    16    1A    1E    22    26    2A    2EDNV   03    07    0B    xx    13    17    1B    1F    23    27    2B    2FSEA   40    44    48    4C    xx    54    58    5C    60    64    68    6CLAN   41    45    49    4D    51    xx    59    5D    61    65    69    6DWAS   42    46    4A    4E    52    56    xx    5E    62    66    6A    6ESNF   43    47    4B    4F    53    57    5B    xx    63    67    6B    6FDAL   80    84    88    8C    90    94    98    9C    xx    A4    A8    ACNWY   81    85    89    8D    91    95    99    9D    A1    xx    A9    ADCHI   82    86    8A    8E    92    96    9A    9E    A2    A6    xx    AEMIN   83    87    8B    8F    93    97    9B    9F    A3    A7    AB    xx

For example, let's say you want to be Chicago and you already beat Seattle,
Dallas, and Cleveland.  You go over to the Chicago column, and go down to
Cleveland (the first one on the list according to the game's order).  So the
first two digits in the password would be "2A".

 

Next, let's look at the following characters of a password: xxxABCxx.  These
work together to tell the game what teams you've beaten.  Remember the numbers
in the first list that I said would be explained in a bit?  Well, that's what
this part is for.  All you do is a add the numbers together.  Include your own
team when doing this.  Also think of the letters as numbers: A=10, B=11, C=12,
D=13, E=14, and F=15.

 

Let's look at another example.  You're Chicago and you already beat Seattle,
Dallas, Washington, San Francisco, and Cleveland.  You'd add up the columns
like so:
0 0 4 (Cleveland)
0 1 0 (Seattle)
0 4 0 (Washington)
0 8 0 (San Francisco)
1 0 0 (Dallas)
+4 0 0 (Chicago)
------
5 D 4 (D because the middle column adds up to 13, which corresponds to D.  You
        don't carry the one or anything.  Add up each column individually).
The password for this example so far would be: "8Ax5D4xx".

 

Now for the last part of the password: xx1xxx23.  This part of the password is
by far the most coomplicated.  It took hours to figure this out.  Like the
chart above, you want to find the team you are on the first line.  Then go
down that column until you get to the first team on your list of beaten teams.
The numbers in this chart can be thought of as base sets.  Once you find the
base set you need, we'll need to do some adding.

 

Notice that this chart has an extra column labeled ++.  It also has a gap after
Denver.  The first four teams affect the 3rd digit in the base.  The last eight
teams affect the 1st and 2nd.  To find the first number, start with your base
and add the numbers in the ++ column for each team on your "teams beaten" list.

When you add, you have to think of the digits as a cycle. Once you get to F,
the next digit would be 0, then 1 and 2 and 3 and soforth.  After 9 is the
letter A.  So if your base has a C, and you need to add 6, then you would count
D, E, F, 0, 1, 2. Do NOT use the number in the ++ column that corresponds to
the base set.  If you are Indianapolis and Seattle is the base, do not add the
1 for Seattle.  You DO, however, need to use the number that corresponds to
your own team.

 

If you go from F to 0, you need to mark up the 2nd digit in the base.
For example, if the first two are C8 and you have to add 6, the first number
would be 2 and you'd have to mark up the 8 to a 9.

 

For the 3rd number in the base set, you have to look at the first four teams.
Similar to the 1st number, you find your base, but this time you use the
numbers in the ++ for the first four teams only.  Once again, do NOT use the
number in the ++ column that corresponds to the base set, but DO use the number
that corresponds to your own team.  If you go from F to 0, you'll have to mark
up the 1st digit in the base.

    IND - MIA - CLV - DNV - SEA - LAN - WAS - SNF - DAL - NWY - CHI - MIN - ++IND  xxx   B89   B8A   B8B   B8C   B8D   B8E   B8F   C80   C81   C82   C83   1MIA  B8A   xxx   B8C   B8D   B8E   B8F   C80   C81   C82   C83   C84   C85   2CLV  B8D   B8E   xxx   C80   C81   C82   C83   C84   C85   C86   C87   C88   4DNV  C82   C83   C84   xxx   C86   C87   C88   C89   C8A   C8B   C8C   C8D   8SEA  C8B   C8C   C8D   C8E   xxx   D80   D81   D82   D83   D84   D85   D86   1LAN  D8C   D8D   D8E   D8F   E80   xxx   E82   E83   E84   E85   E86   E87   2WAS  F8D   F8E   F8F   090   091   092   xxx   094   095   096   097   098   4SNF  39E   39F   490   491   492   493   494   xxx   496   497   498   499   8DAL  C8F   D80   D81   D82   D83   D84   D85   D86   xxx   D88   D89   D8A   1NWY  E80   E81   E82   E83   E84   E85   E86   E87   E88   xxx   E8A   E8B   2CHI  091   092   093   094   095   096   097   098   099   09A   xxx   09C   4MIN  492   493   494   495   496   497   498   499   49A   49B   49C   xxx   8

Let's look back at the last example with a few changes.  This time you are
Indianapolis and you've beaten Dallas, Seattle, Washington, San Francisco, and
Cleveland.  Go to the Indianapolis column and go down to Cleveland.  Your base
set is B8D.  We have Dallas (1), Seattle (1), Washington (4), and San Francisco
( from the bottom eight teams: 8+1+1+4=14.  So we need to add 14 to the B.

 

This gives us C, D, E, F, 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9.  The new first
digit becomes 9, and since we went from F to 0, the 2nd digit gets marked up to
9.  We don't add the 4 for Cleveland since that is the base team, but we do add
the 1 for Indianapolis.  So the 3rd digit now go from D to E.  Our final
3-digit set is 99E.  The incomplete password would look like xx9xxx9E.

To finish the password, use chart one to see first two digits are 02 and the
remaining three add up to be 1D5.  This makes the finished password 0291D59E. "

[keithisgood]

How I missed that is beyond me, but as usual, Brud, you da real MVP.

[TwoScoops]

This is mostly right, but I found a simplification and thought I'd throw in an example.

 

In this case, I (SF) have defeated, in order, DEN, WAS, MIN, MIA, DAL

 

We'll break the number into !@#$%^&*

!@ is from the code as described above. I'm sure you could pick whoever you want, I pick my most recent team since that is what Tecmo does while you play. The chart is accurate and looking at it you get 9C for a defeat of Dallas. Similarly, the description of $%^ is correct. Adding up the teams gives 9CA. 

 

Right now we have 9C#9CA&*, needing to solve for #, &, and *. Again, the base for these digits is correct, going down the table to see where SF beat Dallas (again, game uses most recent victory though I'm sure it's irrelevant, it's just the only way I can test.) Dallas is D86.

 

6 + teams from first block = 10 (Denver = 8, Miami = 2), so we add 6 + 10 = 0. We carry the one to the D. So those last 3 are now E80. In fact, we now know 9C#9CA&0.

 

#=E, &=8.

 

We go again, adding 20 (8 for MIN, SFO, WAS and 0 for DAL since they were the team used to derive this base set). 

E+20=34=2=#. Since we rolled over twice we add 2 to 8 to get A.

 

Final password = 9C29CAA0. 

 

So, mostly the same, but it doesn't have to be the first team in the order you beat, it could be any, and most notably if you roll over on the very last digit, you add it to both # and &, not just # as described above.

Thanks for finding all this!

Edited January 20, 2020 by TwoScoops
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