OS 2.21 From Calc to Computer

[Mighty Moose]

I recently acquired a very ancient TI-84+SE calculator with OS 2.21 still installed.  Is there any way I can get the OS from calculator to computer?
Thx.

[DJ Omnimaga]

Mhmm I'M not sure if this is possible. You might want to check if TI-Connect got such option, or maybe check TiLP (make sure only one is installed at once)

[Lionel Debroux]

TILP should be able to perform ROM dumps, indeed.

[DJ Omnimaga]

I think he wants to copy the OS to his computer, though, not a ROM.

[calcdude84se]

Yeah, I don't think any existing software can do this. To briefly outline the procedure, you'll need an ASM program that dumps each page of the OS into a 16KB appvar. Then those appvars need to be sent to a computer, and a program assembles them into a .8xk.

[DJ Omnimaga]

How do you use the OS afterward, though? Do you just run the app and it overwrites the OS sectors?

[calcdude84se]

hm? The computer program would generate a .8xk, just like TI's official ones.
The theoretical on-calc program just reads the OS; it doesn't change it

[TC01]

hm? The computer program would generate a .8xk, just like TI's official ones.
The theoretical on-calc program just reads the OS; it doesn't change it

I think you mean .8xu. .8xk is app format, .8xu is flash OS format.

[calcdude84se]

Oh, definitely. My mistake. 8xu it is.
* calcdude shouldn't have made such a silly mistake.

[DJ Omnimaga]

Yeah that's why I was confused, as I thought the file would have to be a 8xu file.

[FloppusMaximus]

What calcdude84se is describing is a ROM dumper (albeit somewhat harder to use than your typical ROM dumper.)  The OS is part of "ROM", you know.

Presumably the question is how to convert a binary ROM image into an 8xu file that you could install on another calculator, and the answer is, as far as I know there isn't any program to do that.  But it wouldn't be difficult to write.

[DJ Omnimaga]

Ah right, the ROM contains the OS. From what I recall, Critor had a ROM to OS converter, as he took a Flash Debugger TI-73 ROM file (clc I think) and converted it to an OS. I then installed it on a real TI-73 to see if it worked. It was a rare OS too, from what I remember.

I'll go check TI-BANK website later to see if it was hosted there.

[FloppusMaximus]

Here's a program that should work to convert an 83+/84+ ROM image to an 8xu file.  It doesn't sign the OS or even check that the signature is valid; garbage in, garbage out.

Funny story: the first real ROM image I found to test this on was a dump of a TI-83+ running OS 1.12.  So I ran the program and compared the results against os112.8xu.  I was expecting to see a few differences between the two files (the date stamp is different, and TI's older OS files don't have the version number in the header.)  But as it happened, the two files matched even more exactly than I had hoped... because it turns out OS 1.12 was originally released on October 11, 1999.

[DJ Omnimaga]

Wow... 1.12, that brings back some memories. This is what my TI-83 Plus came with when I bought it in July 2001, same for my bro's calc. Is it me or was that OS slightly faster than newer ones?

[coolsnake]

I got TI-OS 2.21 on my good old "Ti Graphing Product CD v 1.1" that came with my TI-84, maybe you do too.
It's near impossible to find it on the internet I think. The closest thing I found was the less buggy TI-OS 2.22