User avatar
terriblefire

Posted Mon May 25, 2020 3:53 pm

nonarkitten wrote:
Mon May 25, 2020 3:51 pm
I think the last hurdle is reverse engineering the PLA chips.
Sounds like the guys have it covered. I really want one of these so happy test (and pay for) when they're ready

User avatar
nonarkitten

Posted Mon May 25, 2020 9:15 pm

terriblefire wrote:
Mon May 25, 2020 3:53 pm
nonarkitten wrote:
Mon May 25, 2020 3:51 pm
I think the last hurdle is reverse engineering the PLA chips.
Sounds like the guys have it covered. I really want one of these so happy test (and pay for) when they're ready
Same.

User avatar
nonarkitten

Posted Thu Jun 25, 2020 1:49 pm

Just saw this project on GitLabs:
https://gitlab.com/MHeinrichs/galdurino

"Most read protected 16V8 and 20V8 can be read with this thing due to a bug in the read protection!"

"Every GAL has two trigger voltages on the EDIT-pin. One to switch into READ-mode and one to switch into WRITE-mode. Usually one can read the GAL putting 12V on the Edit pin. Putting 15-22V (depending on the GAL-Type) on the EDIT-pin triggers the writing mode."

"The read-protection can be fooled, if the read-voltage value is applied before power up (5V on VCC). Sometimes it needs to be close to the READ -trigger voltage (usually down to 9 V ~ 130 Potival) or around the WRITE-trigger voltage (PotiVal 220-230). Sometimes the read-protection is already fooled just by putting 12V (180 Potival) on EDIT before power up ."

"So try different values around 130, 180 and 220. A good read usually has a lot of zeros in each fuse line. Lines completely filled with "1" indicate an unsuccessfull read. Lines or blocks of lines complete filled with "0" are suspicious but could be possible. If you find a "sweet spot" but some lines are "1" try to read again. Sometimes a GAL need some "attempts" to be cracked."

Wonder if this would help decode the PLA chips on the Rejuvenator???

User avatar
intric8
Seattle, WA, USA
Website

Posted Thu Jun 25, 2020 2:27 pm

Thanks for posting, nonarkitten! I will pass this along asap

User avatar
intric8
Seattle, WA, USA
Website

Posted Thu Jun 25, 2020 2:46 pm

@nonarkitten et al
Unfortunately [this doesn't help us]. The Rejuv’s PLDs are PAL, not GAL. They are immune to this vector.

But I am currently testing my pin adapt reader on commodity PALs, to make sure my method is safe.

I should have results soon. I’ve also amassed a large collection of equations used in like-wise projects to compare.

I think I’ve also worked out the address decoding manually using the Amiga memory maps. I hope they jive with what I can get out of the PALs.

I’ve been quiet, but have put quite a bit of time in as of late.
Woooooo!!!

User avatar
terriblefire

Posted Thu Jun 25, 2020 2:54 pm

honestly if i have the rest of the schematic i can infer what the logic needs to be quite simply.

User avatar
nonarkitten

Posted Thu Jun 25, 2020 3:10 pm

intric8 wrote:
Thu Jun 25, 2020 2:46 pm
@nonarkitten et al
Unfortunately [this doesn't help us]. The Rejuv’s PLDs are PAL, not GAL. They are immune to this vector.

But I am currently testing my pin adapt reader on commodity PALs, to make sure my method is safe.

I should have results soon. I’ve also amassed a large collection of equations used in like-wise projects to compare.

I think I’ve also worked out the address decoding manually using the Amiga memory maps. I hope they jive with what I can get out of the PALs.

I’ve been quiet, but have put quite a bit of time in as of late.
Woooooo!!!
Very nice.

As a last resort, for $175 (as reported in 2005, probably higher now), these guys will decapsulate the PAL and jumper the read-protection fuses using a focussed ion beam (that sounds SOOO COOL) to allow PAL devices to be read. https://www.eag.com/

It's' semi-destructive but shouldn't damage the operation of the PALs. We could do a little gofundme to pay for this, I'd happily chip in something for this.

User avatar
intric8
Seattle, WA, USA
Website

Posted Thu Jun 25, 2020 3:16 pm

I have full confidence in Joe. Time has been a precious resource these last several months but we'll get there. He's being very meticulous to do this without any harm, which I very much appreciate.

User avatar
nonarkitten

Posted Thu Jun 25, 2020 3:19 pm

intric8 wrote:
Thu Jun 25, 2020 3:16 pm
I have full confidence in Joe. Time has been a precious resource these last several months but we'll get there. He's being very meticulous to do this without any harm, which I very much appreciate.
But, but ... LASERS! Everything is better with LASERS!! And I know, I'm just super impatient :) Not the best trait in the Amiga community these days.

User avatar
halfbrite

Posted Fri Jul 03, 2020 2:34 pm

If I want to help financially to donate some funds for this project to help move it along(or am I being arrogant in assuming this), is there anyone I can contact?





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