Omnimaga

Calculator Community => TI Calculators => General Calculator Help => Topic started by: ForteGX on September 13, 2013, 12:24:41 am

Title: Hardware needed to downgrade 3.2.4
Post by: ForteGX on September 13, 2013, 12:24:41 am: Hi,
I probably, should have done some more research before buying a Ti-Nspire CX CAS with the OS 3.2.4. But I have been looking around and there is some mention of hardware that could downgrade my OS? I looked around, but I really didn't see what I would need and what I would need to do once I have it. Is there a guide?
Thanks
Title: Re: Hardware needed to downgrade 3.2.4
Post by: DJ Omnimaga on September 13, 2013, 12:29:24 am: Hi and welcome to the forums. :)

Unfortunately, if your calculator serial number (check the back of the calculator) ends with the letter J or higher, then no external hardware will be able to downgrade the calc. However, if your calculator has the letter I or below, then an RS232/TTL adapter is required. There must be guides on TI-Planet website (perhaps some in English).
Title: Re: Hardware needed to downgrade 3.2.4
Post by: ForteGX on September 13, 2013, 12:38:40 am: The number on the back is 2225022676 P-02131, unless the 1's are I's I'm not sure what it means.
Title: Re: Hardware needed to downgrade 3.2.4
Post by: critor on September 13, 2013, 02:52:23 am: In fact it's 2225022676 P-0213I.

You've got hardware revision I, and it came preflashed with the 3.2.4 versions if I understood well.

As for today, we don't know if HW-I can be downgraded to 3.1 versions.

Assuming it cas, you need an USB/TLL interface. They're often using an FTDI chip:
(http://i23.servimg.com/u/f23/13/23/13/53/ttl10.png)
(http://csimg.webmarchand.com/srv/FR/280199982242358/T/340x340/C/FFFFFF/url/convertisseur-rs232-ttl-usb.jpg)

You then connect 3 cables to the following pins on the Dock/J01 port:
(http://tiplanet.org/forum/gallery/image.php?album_id=4&image_id=39)

And you just send the 3.1 Boot2 image file with the HyperTerminal software included on Windows for example.
Title: Re: Hardware needed to downgrade 3.2.4
Post by: Streetwalrus on September 13, 2013, 10:21:38 am: Just so you know, an Arduino Uno with the chip removed can be used as a USB TTL adapter. ;)
Title: Re: Re: Hardware needed to downgrade 3.2.4
Post by: DJ Omnimaga on September 13, 2013, 11:56:00 am: Btw, could someone go to jail if he installed Ndless on his TI-Nspire? I know that someone who hacked his Playstation 3 was sentenced to jail or something after Sony took legal action O.O
Title: Re: Hardware needed to downgrade 3.2.4
Post by: Streetwalrus on September 13, 2013, 04:21:53 pm: Oh you're talking about that German guy who had legal issues because he was working on ps3 Linux or something ?
Title: Re: Hardware needed to downgrade 3.2.4
Post by: Levak on September 13, 2013, 05:53:57 pm: Quote from: Streetwalker on September 13, 2013, 10:21:38 am
Just so you know, an Arduino Uno with the chip removed can be used as a USB TTL adapter. ;)
Why removed ? This (below) works perfectly.
https://tiplanet.org/forum/gallery/image_page.php?album_id=4&image_id=186
Title: Re: Hardware needed to downgrade 3.2.4
Post by: Hooloovoo on September 13, 2013, 06:34:27 pm: You don't even have to be running a sketch on the arduino. If you short the reset pin on the arduino to ground, it acts like a USB TTL adapter.
Title: Re: Hardware needed to downgrade 3.2.4
Post by: Streetwalrus on September 13, 2013, 07:02:09 pm: Yeah, if you don't ground the reset pin or remove the chip it will interfere with the communication.