PROM socketing

[ScanMan]

I will wait on links or terms from the senior members.

Why don't you try searching? If you did you might have found this post (hint it's right in this thread - you might want to read the "Prom Socketing" thread before you actually do it ). Just using the search term "r10 prom mod" would have led to this gem as well...you've got some searching and reading to do!!!

[Rapitharian]

Why don't you try searching?

I did just didn't seem to get the right combo of terms.
Searching is how I found the tread we are in now.

You might want to read the "Prom Socketing" thread before you actually do it ). Just using the search term "r10 prom mod" would have led to this gem as well...you've got some searching and reading to do!!!

Thanks for the Help.
I found the first Post. Thanks for clearing up that the prom there is also for the R10.
The second post I did not find and will read in its' entirety before I make any changes.

Thanks Again,
Rap

[jmayes]

I just did my R10 and used the 'Piggy-Back' method of stacking the new PROM over the OLD one, from what I have read lots of people have damaged or destroyed their boards from trying to remove the old PROM but most people do have the skills to do the soldering. This method may provide a solution for them.

I have attached a Step-by-Step How-to describing how to do it.
I hope it helps!
Jmayes

[mnorton]

I just did my R10 and used the 'Piggy-Back' method of stacking the new PROM over the OLD one, from what I have read lots of people have damaged or destroyed their boards from trying to remove the old PROM but most people do have the skills to do the soldering. This method may provide a solution for them.

I have attached a Step-by-Step How-to describing how to do it.
I hope it helps!
Jmayes

Nice work. I can appreciate this as removing the old chip can cause some tense moments. I've found that using ChipQuik as AlphaWolf has pointed out does work well though.

Noticed that you are using the 2MB 90ns chip. I was wondering if the larger chips would work.

Mark

[pentium101]

I just did my R10 and used the 'Piggy-Back' method of stacking the new PROM over the OLD one, from what I have read lots of people have damaged or destroyed their boards from trying to remove the old PROM but most people do have the skills to do the soldering. This method may provide a solution for them.

I have attached a Step-by-Step How-to describing how to do it.
I hope it helps!
Jmayes

Instead of your method, have you tried soldering 2 low-profile surface-mount PLCC sockets back to back?

You would still have to modify the pin 24 connection, but I would think that this would work.

[jmayes]

Yes, the larger chips work just fine, that 2m chip was the only one I could find on the fly that fit the bill, since it's a double size chip I load the program twice (back-to-back) which allows the extra address pin to be high or low and things still work. I measured it to be low in the tivo but just to be safe I loaded the pgm twice.


I like the back-to-back socket idea! That could even be a item that could be sold to people with limited soldering skills. I will expore that idea. I did solder a socket piggy-back to the first unit I did and found it was extreamly hard to get up under the lip of the socket to do the soldering so I decided that job was not for the Nubies at all but the double socket idea just might work, will report back on that one.

Jmayes

[jmayes]

As I said before I love the idea of the back-to-back socket method, it will allow even a novice to upgrade their TIVO with only one trace cut and one solder connection. I spent today making up a few proto-types of the back-to-back socket assembly and drew up some instructions for building it and installation.

I did run into some issues, first- the socket used on the bottom needs to have it’s notch dug-out, using it backwards and upside down leaves the notch on the wrong corner and it won’t fit over the original prom with out the modification. 2nd, I built two proto’s today, it turns out one would not work at all, the socket fit very loose over the original prom as it was a higher profile type, thankfully the 2nd one fit tight and worked great so you will need to test the socket you choose carefully, not all of them work.

Here are the full instructions,
Enjoy- Tivo Community,
Jmayes

[drez]

Even though I don't have a Series 2.5, I'm grateful you've taken the time to outline your approach.

I actually feel I can do the piggyback method if I ever need to (if S2s ever become scarce)... I don't think I would have ever been confident enough to do actual soldering/send it off to anyone.

[PlainBill]

Good job! My only suggestion - list the socket brand that works, and the one that didn't fit tight.

PlainBill

[jmayes]

I Will post the info on the sockets as soon as I can.


Enjoy,
JM

[pentium101]

Jmayes, very cool!

It looks like this Mill-Max socket from Digikey (Digikey part number# ED80009-ND) should work nicely.

You can read about it here: http://dkc3.digikey.com/PDF/T062/0333.pdf

[AlphaWolf]

Good info. I've been wondering why nobody has tried this before. Something else that might be worth looking into as a community project would be to identify a software exploit, no matter how obscure or difficult to pull off, that would allow arbitrary code execution.

Then add a switch to be able to switch to the new prom after the tivo has already booted, and then do an in-circuit flash.

[jmayes]

A switch is no problem, just toggle the OE signal between the two proms with 1k pull-up resistors installed to each, I will post a hookup diagram when I get some time. I am on the road until Monday so I won't be able to do any quality work until then.

The rom is read one time on boot then there is no activity so making the switch will not cause any trouble, if the 37x original prom can be flashed then my socket jig would only be needed to do the first-hack-boot then flash the original prom then no additional prom would be needed any more. Many people say the 37x can't be in-circuit programmed but the datasheet says is can so this might be a feasible thing to try.


Also I looked at the sockets I used under the microscope today, no markings at all to tell who's they are, I can only tell you that they came from old motherboards so they are Taiwan or China made, we will have to order samples from a few manf's to figure out which sockets will work. The ones that work for sure are the lowest profile kind that the chip actually sticks out a little (when used correctly). If the chip goes into the socket and ends up lower then the sides of the socket then it will not work.


Hope that all helps!
Jmayes

[rc3105]

nice pics jmayes

Good info. I've been wondering why nobody has tried this before.

oh, I imagine a couple of people have...
at this point you're very close to being able to implement a clip-on modchip

Something else that might be worth looking into as a community project would be to identify a software exploit, no matter how obscure or difficult to pull off, that would allow arbitrary code execution.
Then add a switch to be able to switch to the new prom after the tivo has already booted, and then do an in-circuit flash.

er, if you can switch between mb & clip on proms why flash at all?

as for sw explolits, see the modchip thread for why they're kept quiet


it's possible to flash 37's in-circuit but it's hazardous to mb health. if you're willing to cut a trace or three then that's not an issue



if memory serves the whole piggyback-flash process can be this simple

cut 4 pins (or traces)

piggyback modded prom

boot tivo with flashing utils

switch to mb prom, apply erase voltage, flash prom & verify

reboot to double check mb prom

remove piggyback prom & restore original pins


with a prepped disk image, piggyback clip and tools the whole process is less than 10 mins (which is why I don't think it's worth antagonizing TiVo by offering *****-friendly modchips)

[gcherw]

Sonicos was offering to perform prom replacements in the "for sale" section however he has been less than responsive. I was all set to send him my 540's to be upgraded and asked him a couple of questions prior to shipping and I haven't heard from him since 7/7/06. Nonetheless, I didn't send my tivos to him. Is there anyone offering legit prom modding?