Commodore Amiga LIV2 A500/A2000 2MB Chip RAM Mod

[@keithmcgerr3056]

Thanks Gadget & Jeff Goldblum😉 LVI2 what great project & neat board! Looks like Keith's done a alright job on the soldering 😉 thanks once again Sir Gadget!!

[@GadgetUK164]

Thanks 👍

[@rjd324]

Goldblum (seth brundle) needed a 2mb chip upgrade for his pod but didn't get it! No wonder he turned into a Fly!

[@MorganJustGames]

Very interesting video. Expertly done once again Chris. Nice donation and the Sonic Bath works well. I have used one of those before but not for boards. Well done Gadget UK.

[@frankmathieson3029]

Fantastic little project. I`ve been wanting to upgrade the ChipRAM in my A2000 for a while. There are other ways to do but it mostly involves finding an Agnus from an A3000 (which are pin compatible with the A2000) and then replacing the RAM chips. A3000 Agnus chips are VERY hard to find though, so this might actually be an easier way to do it. Thanks for bringing this to our attention.

[@AdamSommer70]

Another great soldering video!!! Thanks for posting, have a great one!

[@GadgetUK164]

Thanks, you too!

[@Dave5281968]

I'm impressed with how you were able to assemble that board. It's definitely not a job for the faint of heart!

[@AsmodeusDeviluke]

I was able to use a Hyundai HY5118164BJC-60, this chip could be added to the list of usable DRAMs. Ordered the PCB though JLCPCB, ordered majority of the components though Mouser. Salvaged the DRAM from a 72pin EDO stick that used SOJ 42 pin chips. Trouble shooting tip, If you are getting a green screen, double check that all pins from the DRAM are making contact with the pads. I had few that looked Ok, but did not pass using continuity test.

[@FernandoelChachi]

A good friend of mine is going to gift me with an A500. I know very few about them as I'm only an A1200 owner. I will love to watch how to fix it first (green screen) and later to upgrade it to the more the better ;). BTW I've sent you a coffe because I love your videos.

[@GadgetUK164]

Thanks, very much appreciated =D Regards the green screen - check out the videos I've done on the Amiga 500 and 500+ Green screen generally means chip RAM fault, but could be bad connection on single wipe sockets (Gary), or damaged Agnus socket. On rare occasion one of the CIAs can cause green screen. Data path is the final thing really - but they seldom fail tbh.

[@FernandoelChachi]

@@GadgetUK164 Many thanks master. Today I've interchanged almost all of the chips with a working board (only Agnus was left because I don't have the extractor yet). Now I'm awaiting to receive some sockets (20 DIP ones) and ram chips. Mine is a Rev. 6, so much better I believe... and less ram chips to change and also easier ways to upgrade it... For what I've seen.

[@d0nKsTaH]

either solder or use hot glue for those pin clips... Helps prevent them from coming off or shorting from movement

[@giuseppelavecchia775]

Assemblaggio perfetto,un bel lavoro

[@MrWaalkman]

I recover my IPA as well and just put it back into the same bottle. I do clean my boards outside since there is a slight risk of fire (I just use a tub and an electric toothbrush and not an ultrasonic cleaner). My big concern with reusing my IPA too many times is that I use it to drive out the water from the rinse step by diluting it with alcohol, so each use dilutes the IPA further.

[@mark12358]

Nice project and nice board. IMHO, in a rev. C it would be practical to have two holes in the pcb below Agnus, moving away tracks and components, if possible. Cheers, M

[@MrLukealbanese]

Chris, is there a link to Sparks UK's channel? I love these chipram expanders. LIV2 also has one for the full PLCC plugs - but they are between 15 and 40 quid each!!

[@GadgetUK164]

He doesn't have a channel! He hangs out in my Discord! Yes, the plugs are a good idea, but as you say - they are expensive =/

[@vaderqrt1731]

how can i buy these boards? great vid and explanation

[@tahustvedt]

Are there pin headers with more heat resistant plastic? That would make it easy to hot air solder them using solder paste. Maybe it's enough to slide the plastic all they was up to the end of the pins while the solder paste is heated by a heat gun.

[@ldisc66]

I could've used this back in the 80s 🤣

[@vaderqrt1731]

Finally I have one of these boards. What is the best way to have 2mb ram from the trapdoor expansion? I have one expansion with Gary adapter, but the middle JP2 jumper as to be free, and with this 2mb chip ram the top 1,2 jumper JP2 must be together :/ Or more simple question: can you put the boobip 2mb ram working with this set up?

[@GadgetUK164]

In a 500 you need to make sure the jumpers are set as if it has an 8372A - So the 512K in the expansion slot is chip RAM. If using the Boobip I suspect you may end up with 1.5MB of chip RAM and 2MB of slow RAM.

[@newsolution5669]

Does anyone have documentation and technical diagrams of the integrated circuit Agnus ??? where can I download it?? how to get them??

[@GadgetUK164]

The nearest thing is the datasheet for the original Agnus - retro-commodore.eu/files/downloads/amigamanuals-xiik.net/Hardware/Specifications%20Agnus%20-%20Manual-ENG%20.pdf Probably prior to becoming the Fat Agnus - not sure, I haven't looked. So you would need to look at the clock gen stuff on the early 2000 schematics or 1000 schematics to work out the rest. Alternatively, look at MiSTer source code for the Amiga core(s) - as I am sure someone has probably created it in VHDL or something already. Stephen Leary (TerribleFire) did also create a version of the Agnus, and I believe handed over to Renee Cousins (Buffee - Amiga Project team).

[@pkf4124]

I have one of the original DKB Agnus adaptors in my 2000. Fully plan to build one of these to put in my 500. Shame the Agnus chips are so expensive now.

[@GadgetUK164]

Yes, prices of Agnus chips have gone nuts =/

[@pkf4124]

@@GadgetUK164 I wish some talented sort would work out how to make one on a fpga chip, then may be we could get more than 2mb. I recall reading somewhere Commodore were planning bigger Agnus revisions.

[@TrashTheLens]

I'm wondering wouldn't it be easier to use single strips of pins instead of the double ones? Solder the inner circle first (by using a single row you could access the inner pins from the outside) and then do the outer circle. Or am I missing something?

[@GadgetUK164]

That's a good idea!

[@willynebula6193]

You would have to get the alignment bang on tho.

[@FernandoelChachi]

Excuse me. I've seen that you've got the same Ram expansion (A501) that I've just repaired (a bit), but I haven't tried yet. The battery was showing some corrosion around (not much) and I've replaced it with a button battery socket. My question is: Do I need to cut any trace or is it ok if I use a rechargable battery?. A lot of thanks for your work.

[@FernandoelChachi]

I've bought a modern button rechargable battery from AliExpress (LIR2032, Lithium) . I don't know if that's ok or what.

[@GadgetUK164]

You shouldn't use a rechargeable LIR2032 without a modification to the charge circuit! It's better to do the mods I did and fit a CR2032, or fit a rechargeable capacitor perhaps - make sure its a higher rated voltage than the charge voltage though.

[@FernandoelChachi]

@@GadgetUK164 Wow. Thanks for the answer. I'll desolder the socket then; much easier for something I don't need.

[@GadgetUK164]

By rechargeable capacitor - I mean Super Cap btw =D

[@FernandoelChachi]

I'll put a diode instead as I've seen.

[@SimonZerafa]

Is this kit available preassembled? 😮 That looks to be a masterpiece of design and a nightmare for me to assemble! Aren't you supposed to use a special fluid for ultrasonic cleaners? Fairly sure that Louis Rossmann had a rant about that fairly recently 😉

[@GadgetUK164]

I am not sure it is atm - but it may appear on AmiBay at some point. Regards fluid, yes - you are! As you will see in the upcoming video, the PCB cleaning fluid I used made the solder points on a few boards go dull =/ So I followed Dennis's advice and just used IPA - it was far better that way!

[@danielson9579]

I wish that there was a way of upgrading the A1200s chip ram

[@GadgetUK164]

Yeah, it would be nice to go to 4MB or 8MB of Chip RAM, but it needs the main chipset to support it (eg. Alice, Lisa, Paula probably).

[@malcolmogilvy4885]

Awesome but think ima buy one pre-made my soldering sucks lulz

[@batteryjuice3041]

For some reason you remind me of Sean connery, how can that be... =)

[@eukat3ch]

is that the new intro ?

[@GadgetUK164]

No, I've not changed the short retro unlim intro - the video I pushed out the other week was a new "Channel Intro" - the video that people see when they first land on my channel. It was 2 mins long, too long for an intro to each video I think!

[@televiciousgoober]

If anyone has 2MB ntsc chips hmu.

[@tetsujin_144]

Aren't 2MB Agnus chips region-switchable? I don't have an 8375 but I did upgrade my Amiga 500 with an 8372 (for 1MB chip RAM) - and gained region switching ability as a bonus...