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critor


Member


Joined: 04 Feb 2009
Posts: 132

Posted: 29 Jun 2009 06:09:25 am    Post subject:

Hi,


I've found 2 very old TI-82 calculators with ROMs 10.0 and 11.0 (last one was listed nowhere on the Internet).

I'd like to dump their roms (in order to "save"/archive them as nobody has ever dumped them, to compare them with more recent roms, to document them so that assembly programs can be run on them, and to emulate them)


For reference, TI-82 ROM versions can be to my knowledge: 3* 4* 7* 8.0 10.0 11.0 12.0 15.0 16.0 17.0 18.0 19.0 19.006


All shell versions I've tried on 10.0 and 11.0 (3 SNG versions, 2 Ash versions, 6 CrAsh versions...) "crash" at the 1st assembly use (the calculator just freezes, or displays the "FAILED" system message before being resetted by a key press)

Shells with a comprehensive ReadMe, state they have been designed for roms 16.0, 17.0, 18.0 and 19.0.
A minority of them work on the last rom version (19.006).

So I can't even use assembly dumping programs on roms 10.0 and 11.0.


After reading "Hacking the TI-85" by David Boozer ( http://www.ticalc.org/pub/text/calcinfo/85hack.txt ), I've developped a corresponding dumping method for the TI-82, which works without any assembly code.


The Z80 can address a maximum of 64Kb.
Memory chips are mapped this way:

0000-3FFF ROM Page 0 (16Kb)
4000-7FFF ROM Page 0-7 (16Kb)
8000-FFFF RAM (32Kb)


1) On the calculator, create variable Pic1
2) Disable axes (AxesOff)
3) Create a program which recalls Pic1, and saves screen to Pic2
4) Backup the whole RAM.
5) On the computer, modify backup file, so that Pic1 will have an address in ROM (to begin, 0000).
6) Restore backup to the calculator.
7) Run program.
Cool Send back Pic2 to the computer.
9) On the computer, modify backup file, by adding 756 bytes (2F4) to Pic1 address.
10) Go back to step 6.

By using this method, I was able to dump ROM page 0 (0000-3FFF -> 16Kb) in 22 image files.

I've also dumped betweend 4000 and 7FFF - but I don't know if the ROM page did change during the dumping.
If not, it seems to be ROM Page 3.


So dumping is at 25%...


And now the big question...

How can I do to dump the other rom pages?


Is there a simple (non assembly) way, to check/change the rom page?


Thank you very much.
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ztrumpet


Active Member


Joined: 06 May 2009
Posts: 555

Posted: 29 Jun 2009 06:49:16 pm    Post subject:

Wow. That's fasinating.
Good Luck. Smile
(I don't have an 82 or a lot of knowledge of how the calculator works, so I can't help)
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FloppusMaximus


Advanced Member


Joined: 22 Aug 2008
Posts: 472

Posted: 04 Jul 2009 02:42:27 pm    Post subject:

Since all variables on the TI-82 are stored in RAM, the "Pic" method you describe won't help you retrieve data from other ROM pages. What you've dumped from the 4000-7FFF region is almost certainly all from one particular ROM page (the page that contains the "RecallPic" routine; I don't know which that is.)

However, once you have a copy of ROM page 0, it's possible to write a shell for the calculator, or to add support to SNG. (I can probably help with this, but maybe we should discuss it privately.) From what I know of the TI-82, there is probably very little difference software-wise between ROM 10.0 and 16.0, and effectively no difference hardware-wise. Once you have a shell running, of course, dumping the full ROM is easy.
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critor


Member


Joined: 04 Feb 2009
Posts: 132

Posted: 07 Nov 2009 04:28:11 am    Post subject:

Oh, I forgot to post back here...

The 10.0 and 11.0 ROMs have been fully dumped 4 months ago.


I had to put the ROM page switching + ROM to image dumping code in the hacked backup file.





I've archived the ROM files - those systems won't disappear when the last 10.0/11.0 TI-82 will have died...


Now it would be nice if I could find old TI-82 calculators with ROMs 4* 7* 8.0 12.0 15.0, and "save" their ROM too...
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ztrumpet


Active Member


Joined: 06 May 2009
Posts: 555

Posted: 07 Nov 2009 10:50:21 pm    Post subject:

How do you tell what ROMs they are on an 82?
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critor


Member


Joined: 04 Feb 2009
Posts: 132

Posted: 08 Nov 2009 11:21:10 am    Post subject:

ztrumpet wrote:
How do you tell what ROMs they are on an 82?


Just type: 2nd MODE ALPHA S

This will access the Self-Test screen, which shows the ROM version.


There is supposed to be many TI-82 ROM versions:

3*: listed on ticalc.org - probably uncompatible with all shells - no proof of existence found...
4*: listed on ticalc.org - probably uncompatible with all shells - no proof of existence found...
7*: listed on ticalc.org - probably uncompatible with all shells - no proof of existence found...
8.0: listed on ticalc.org - probably uncompatible with all shells - no proof of existence found...
10.0: I've got one - uncompatible with all shells - I've dumped it using a hacked backup file - ROM dump is in a private folder on one of my web sites and nowhere else (*)
11.0: I've got one - uncompatible with all shells - I've dumped it using a hacked backup file - ROM dump is in a private folder on one of my web sites and nowhere else (*)
12.0: I don't have it - but it does exist, as there is a photo on DataMath.org ( http://www.datamath.org/Graphing/JPEG_TI-82_OS.htm#12.0 )
15.0: listed on www.ticalc.org - no proof of existence found...
16.0: compatible with assembly shells - ROM dump is widely available online
17.0: compatible with assembly shells - ROM dump is widely available online
18.0: compatible with assembly shells - ROM dump is widely available online
19.0: compatible with assembly shells - ROM dump is widely available online
19.006: only included in the TI-82 with a Parcus case - hardware is totally different: a TI-83 motherboard, with the TI-82 memory chips - only 2 shells were updated for that version - uncompatible with all other shells - ROM dump is quite rare online

(*) It's not that I don't want to share... It's just that I've read many storied of TI sending letters to people who put ROMs publicly on their web pages...


Last edited by Guest on 08 Nov 2009 11:22:52 am; edited 1 time in total
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FloppusMaximus


Advanced Member


Joined: 22 Aug 2008
Posts: 472

Posted: 08 Nov 2009 09:38:14 pm    Post subject:

I seem to remember that one of the older TI-82 shells claimed to support one or more of the "star" versions.
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critor


Member


Joined: 04 Feb 2009
Posts: 132

Posted: 09 Nov 2009 12:43:25 am    Post subject:

FloppusMaximus wrote:
I seem to remember that one of the older TI-82 shells claimed to support one or more of the "star" versions.



I've downloaded all TI-82 shells available on ticalc.org and...
You're right! (it was the last one)

JASS 0.1b is claiming to have some support of the 7* ROM, and a full support of ROMs 16.0, 17.0, 18.0 and 19.0.


But when I tested it on ROMs 10.0 and 11.0 it did crash.
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AdamOrBud


Newbie


Joined: 12 Aug 2010
Posts: 8

Posted: 22 Aug 2010 03:30:09 pm    Post subject:

hey!!! I've had a similar problem!!!!

I've actually got ROM 1.0!! haha

it's unfortunate, however, because I cannot run ANY shells effectively whatsoever


like....at all.

they crash every time and eliminate the entire unit's memory
(which isnt a total loss at this point because the stuff i wan to
use in the first place is all assembly)

ive attached an image of what i'm dealing with....


any help would be eternally appreciated....
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