and its gal my brain keeps saying pal, but its gal.

Persistance will always give rewards, great job dude

Wow Dr Cee! That was a doozy of a problem. Definitely learnt something from this video. Didn’t know that some of those chips could be re-programmed… 🤔🤯 Nice! Cheers! 🍻

Failure is not an option. Well done Chris took some time but made it in the end.

The gate array logic (GAL) will lose logic state over time. I used work at a computer company. Sometimes, they did not program the PAL ic. It took about an hour of troubleshooting to find the unprogrammed ic. Congratulations on finding the cause!

Another epic repair by the master... Great job!

A few years ago I had the same problem! Best regards and congratulations on finding the cause!

Awesome!!!! Salvage of an other Amiga machine 👍👏👏👏👏👏👏 you rock Chris!!!!

That is a new one mate. Nicely done. Never knew that one and never seen anyone think to look that way and there.

Brilliant Chris! We now know these gals can just go “blank” and should be checked.

perseverance is key...well done.

GAL was all danced out... needed a drink.

Absolutely Great! 🤩 1 Million Thumbs Up👍🏻

always great to watch you work, its great how you dont give up like a dog with a bone. Well done sir!

Great job Chris. Greetings from Steven from the Netherlands

Hi pal I hope you had a good holiday

Amiga's are not allow to die, if Chris has anything to do with it ..

@ChrisEdwardsRestoration

9 ай бұрын

not always but i try to do my best.

Fixed!

Great stuff Chris, I have a revision 2b board in a similar state. Would a GAL16V8D10LJ be correct for this board? I suppose the original one can be reprogrammed too?

@ChrisEdwardsRestoration

8 ай бұрын

Ues they are electronic erase and prog. You may just need to reprog your orig

Does anyone know where the additional info Chris found about the reset lines and chip locations can be located.

@ChrisEdwardsRestoration

9 ай бұрын

here go eab.abime.net/showthread.php?t=98896

Hi Chris, GOOD find mate, im crazy with mine with SAME DIAGNOSTIC as yours, time to check gal. Any test to do in GAL for its in working condition before take it out from the motherboard?? I dont have a PLCC programing, any recommendation for buy one? Thanks Chris.

@ChrisEdwardsRestoration

6 ай бұрын

Pull it and read it. If its all 1’s its blanked itself. They are reprogrammable so just re write the jed file to it. If it takes its good if it fails replace the pal

Nice job chris please dont get a syrup.

@ChrisEdwardsRestoration

9 ай бұрын

Syrup?

@MrFixiit

9 ай бұрын

yeah cockney for wig syrup of fig = wig :p@@ChrisEdwardsRestoration

@ChrisEdwardsRestoration

9 ай бұрын

@@MrFixiit that cockney slang is some weird stuff. but each area has their own little sayings. like my weird ones here.

Great job! It always feels good to finally fix something, even if it was just a stupid issue. Happens to me all the time. Anyway, what does the pal (or gal) actually do? Googled for it but couldn't find it.

@ChrisEdwardsRestoration

9 ай бұрын

think of them as little cmos chips, but now electronically erasable over they;re hard coded pal cousins.

@robertgijsen

9 ай бұрын

@@ChrisEdwardsRestoration I know it's a bit like an eeprom, but what's it's function in the miggy? What does it store? Googling it I found a lot of 'romdumps' of it, so it's like static code in there? Or does the amiga store settings in there or something. Can't think of anything my A500s and A1200 would store.

@ChrisEdwardsRestoration

9 ай бұрын

@@robertgijsen the 2000 has 4 actually. they are like little gates, the first iteration of fpga in a sense, like a programmable logic chip, it holds a small program which tells it what to do. it doesnt run like a program, but in logic, like if input A is low then output pin3 should go high. and other things... each one is different, and has different functions, on the amiga, it can be hard disk control, floppy control, DMA access for Ram, and many more things. in this instance, the Xu9 GAL chip on the 1200 is responsible for many little things. mainly Rom start , and clock handlingto the other chips, it has 8 input and 8 output states, and 2 power and a ground onboard. it replaces about (4) 74LS TTL logic chips on a similar board. its a cost reducing way think fpga is the best way i can describe them. its different than regulare logic chips as logic has to run and compare itself against "truth Tables"" which are hard coded. it gets deep.... so lets just say like i do, "Math and Science stuff" but thats it in a nutshell. Hope it helps

@robertgijsen

9 ай бұрын

@@ChrisEdwardsRestoration thanks for the explanation! I know my way around retro electronics and FPGA as well even though I never used one. So this one replaced some glue logic. Good to know.

Good thing chip is eraseable. Bad thing when it gets erased on the board. Board went through something that erased chip?

@ChrisEdwardsRestoration

9 ай бұрын

microwave? nuclear event? lightning strike? i dont know their back stories... like old girlfriends, sometimes its best not to know.

Hi Chris. Congratulations for the video. I learned a lot from your videos. I have an A1200 that I've been trying to resuscitate for years, but without success. The reset signals, clocks, etc. are all OK. There are no faulty tracks, I did the recap twice, I changed the ROMs, I tried almost everything, but the Amiga won't boot. The version of my A1200 is 2B. I would like to replace the GAL (XU1), but I can't find the source code for it. I have a TL866, just like yours and some GAL 16V8B-15, but I don't have the source code for it. Where can I find this code? Thank you very much.

@ChrisEdwardsRestoration

9 ай бұрын

It’s dangerous to go alone take this! www.amigawiki.org/doku.php?id=de:parts:pld_download

@dghummel1956

9 ай бұрын

@@ChrisEdwardsRestoration Hi Chris. Downloaded! I'll try tonight. And I will post the result here. Thank you very much.

@Cyberstormxiii

Ай бұрын

@@dghummel1956 so, what happened - did the reprogramming of the gal yield any positive results?

Would you Ever be Interested in Repairing my Amiga 1000 Rev A. I've been poking at it for a month and documentation is so Scarce for the 1k.

@ChrisEdwardsRestoration

2 ай бұрын

whats wrong with it.

@Space_Bub

2 ай бұрын

So, it’s not booting at all, no LED blink codes, no floppy activity, 1/10 power ups results in a garbled mess. (The LED is on but stable.) I’ve removed all modifications, disk drive, Parceiro ii, mouse and keyboard dongles. Reseated all the chips tested voltages a bit but I’m unsure of what to look for. This isn’t a barn find either, it’s the centerpiece of my music studio that booted as recently as a month ago. I put it in the original box to clean the studio, when I hooked it back up and black screen of death. Thought it was RGB2hdmi, but removing that didn’t work, ordered 2 8250 CIA chips, and a recap kit awaiting their arrival. I found the component level repair manual for the A1000, but still have no idea where to start. I would happily pay for the services and parts, and would be cool to see you document an A1000 repair as they are becoming extremely rare and maybe save someone else along the way. @ChrisEdwardsRestoration

@Space_Bub

2 ай бұрын

@@ChrisEdwardsRestoration I replaced the 8520s and recapped the MOBO and daughterboard with no luck.

@ChrisEdwardsRestoration

2 ай бұрын

I will help shortly just backed up like a truckstop toilets at the moment

@Space_Bub

2 ай бұрын

@@ChrisEdwardsRestoration HAHA, NBD, Just replaced the EVEN and ODD IC's, Still No Luck. I'm Gonna put it back in the box for a while, I'm So Tired. heh

1200 takes about 40 seconds to show a screen with no IDE.

@ChrisEdwardsRestoration

9 ай бұрын

Yeah but you didn’t watch the video then

@hamrdeye8927

9 ай бұрын

@@ChrisEdwardsRestoration No I did, I know that wasn’t it but it didn’t look like at first you giving it long enough. I commented as I watched :) I know when I got my first 1200 and turned it on, I thought it was broke. I just wasn’t waiting long enough :)

@ChrisEdwardsRestoration

9 ай бұрын

@@hamrdeye8927 i also had a df0 terminator in so that lets it instaboot

@hamrdeye8927

9 ай бұрын

@@ChrisEdwardsRestoration Does that make it bypass the HDD wait time?

@ChrisEdwardsRestoration

9 ай бұрын

@hamrdeye8927 yup as df0 has best boot priority

With watching your videos, we now know what the symptoms are and how to fix it, unfortunately it took you many hours. Gals will be the death of us all. 😀

...and poor :D