it seems Critor from TI-BANK might have found the issue, but it's still uncertain:

Start reading there http://www.unitedti.org/forum/index.php?s=f7b7b9f492cb8540d0c2338e370f28db&showtopic=8913&st=120&p=137093&#entry137093

Hi people.


First, I wanted to look at hardware revisions to know which ones could use the 128Kb RAM and whice ones couldn't...

And my tests made the UTI thread ran into a wall: some hardware revision (JKL) could pass and fail the test...


So I got another idea.

And it's becoming more and more certain now...


Let's look at a TI-84+(SE) serial number.

It ends with something like:
A-1111B

where:
A is the manufacturer (S or P - both factories are in China)
1111 is the manufacturing date in format MM/YY
B is the hardware revision (A to M)

Here is my table, copied from UTI:
End of Serial   |128K RAM test   |LCD FPS test   |Boot Code   |CPU   |Type   |ASIC
                |(OK/FAIL)       |(120/240/280)  |(1.00/1.02) |(MHz) |(BE/SE)|(CPU/RAM chip)
----------------+----------------+---------------+------------+------+-------+------------------
S-0304          |                |               |            |      |BE     |TI-REF 83PLUSB/TA2
S-0504          |OK              |120            |1.00        |13.6  |BE     |TI-REF 83PLUSB/TA2
S-0504          |                |               |            |      |SE     |TI-REF 83PLUSB/TA2
S-0704          |OK              |               |            |      |       |
S-0704A         |OK              |               |            |      |       |
S-0804          |                |               |            |      |BE     |TI-REF 83PLUSB/TA2
----------------+----------------+---------------+------------+------+-------+------------------
S-0305C         |OK              |120            |1.02        |14.5  |SE     |TI-REF 84PLUSB/TA3
S-0605C         |OK              |               |            |      |       |
S-0605D         |OK              |               |            |      |SE     |
S-0306F         |OK              |               |            |      |       |
S-0506F         |OK              |120            |1.02        |15.2  |SE     |TI-REF 84PLUSB/TA3
S-0606F         |                |               |1.02        |      |BE     |TI-REF 84PLUSB/TA3
S-0207G         |OK              |               |1.02        |      |       |TI-REF 84PLUSB/TA3
S-0307G         |OK              |120            |1.02        |      |BE     |TI-REF 84PLUSB/TA3
S-0407G         |                |               |1.02        |      |SE     |TI-REF 84PLUSB/TA3
----------------+----------------+---------------+------------+------+-------+------------------
S-0607H         |FAIL            |               |            |      |       |
----------------+----------------+---------------+------------+------+-------+------------------
K-0308J         |FAIL            |               |            |      |       |
----------------+----------------+---------------+------------+------+-------+------------------
P-0308J         |FAIL            |240            |1.02        |15.9  |BE     |TI-REF 84PLCR/TA1
P-0308K         |FAIL            |               |1.02        |      |BE     |TI-REF 84PLCR/TA1
P-0308L         |                |               |1.02        |      |SE     |TI-REF 84PLCR/TA1
P-0408L         |                |               |1.02        |      |SE     |TI-REF 84PLCR/TA1
P-0508M         |FAIL            |120            |1.02        |15.7  |SE     |TI-REF 84PLCR/TA1
P-0808M         |                |               |1.02        |      |SE     |TI-REF 84PLCR/TA1
P-0509M         |FAIL            |2x0            |1.02        |      |       |
So you may notice severall things:

* sometime between late 2007 and early 2008, TI did transfer it's TI-84+(SE) production from the S chinese factory to the P chinese factory

* every TI-84+(SE) which fails the RAM test comes froms the P factory

As JKL hardware revisions were produced during the "critic" period (factory change), it could explain the various results:
JKL manufactured by S have 128Kb RAM usable
JKL manufactured by P have 48Kb RAM usable


We're still collecting test results for now.
So please, if you have a TI-84+, report the end of its serial number, and if the extra 128Kb RAM is usable (or if you prefer, if you can play the Game Boy emulator).


When we'll be sure the problem comes from the P-factory, we'll have to find two "theorically" identical calculators coming from both factories(same hardware in theory: JKL, same Boot Code, same model, same OS), and look for the difference.

When the difference is found, we'll have to solve the problem (if possible - if the 128Kb RAM is still there...)

EDIT: DJ: Updated table

nice, that could make things more understandable...

One thing I still wonder, though: Does these new 84+ got that 128 KB of RAM and is it just that only 48 KB is accessible in the ways we know or did they really remove 80 KB? The later almost seems impossible since a RAM chip can be 1 KB, 2,4,8,16 KB, but it kept multiplying by 2, so it jumps to 32 KB then 64 KB afterward. I wonder if a 48 KB RAM chip would even be possible at all? (or maybe they used one 32 KB chip along with a 16 KB one, but I kinda doubt it)

EDIT: Another thing I still wonder: does TI still produce calcs in Taiwan? One of my TI-83+ (the first I got) and my TI-83+SE are from Taiwan, but they were manufactured before the end of 2001

i've not run the tests on mine yet. mine is s-0306 with usable 23k ram

In 2006, there must be some letter after 0306...
It can't be the 1st hardware revision any more.
Can you check please? You should get something like DEF.


Ans please, do run the tests (or just try to run a Game Boy rom).

The system will allways show you 24Kb usable RAM, wether the chip is 32Kb, 48Kb or 128Kb.


But on the TI-84+ manufactured by S, the RAM chip is 128Kb big, and we can access the whole chip, and so play Game Boy roms.

On the TI-84+ manufactured by P, only 48Kb seem to be usable... We can't play Game Boy roms for now...


We need assembly tests to check that.

Thanks

P-0308K isn't mentioned in your tabel
Obviously fails at tests and running Ti-Boy
crap

Thanks! It's a very insteresting TI-84+ (right during the "critic" period).
Updated.

Thanks

Quote from: NecroF-_-ckk on October 04, 2009, 07:11:05 am

P-0308K isn't mentioned in your tabel
Obviously fails at tests and running Ti-Boy
crap

Thanks! It's a very insteresting TI-84+ (right during the "critic" period).
Updated.

yw
btw, wanna trade?

yh I read it :X EDIT: they have way less conections ><
So, when are we going to send bomb-packages to TI?  

EDIT:
Idea: Put all the testing things in one program (with a menu to switch between them) and put an attachment on a topic on the Ticalc site, they'll be interested to help, and since Ticalc still gets a lot of visitors you'll gain information quickly.
The reason to put them in one app/prgm is many people are too lame to use them else
EDIT2: let someone TI-famous post it, like Calc84Maniac, it'll attract more readers

Well now, that's pretty cruddy. I guess TI finally decided to 'correct' their 'problem' of wasting a 128KB TA3 chip by replacing it with a 48KB TA1 chip. Bloody 'eck, that was totally not fair

But that's still strange, because a 48Kb chip cannot exist...
It's not a power of 2!!!
Unless they've put a 32Kb chip,  plus a 16Kb chip inside that TA1 CPU/RAM combo chip...

Note, we're still note sure if TI did cut the RAM or not...