Finally, a reliable inexpensive RAM upgrade for the Atari ST! (That you can make yourself)

It's difficult to upgrade the RAM on a lot of early Atari ST machines. The upgrades that were commercially available back in the heyday of this machine were all pretty flaky could cause damage to your machine.
In this video, I'll show off an upgrade created by Anders Granlund that while hard to install, promises to be super reliable and cause no damage to your machine. You can also make it yourself!
--- Video Links
Part 1: • This Atari was nearly ...
Part 2: • I figured out what is ...
Part 3: • Retrobrighting worked ...
Part 4: This part!
SMMC 0012 Atari ST 4mb RAM upgrade:
• 0012 Finally, a reliab...
Project for 4mb RAM upgrade for the Atari ST by Anders Granlund:
github.com/agr...
Indoor Retrobriting: (Blue box)
• A new way to fix yello...
• Indoor Retrobrite Foll...
Adrian's Digital Basement ][ (Second Channel)
/ @adriansdigitalbasement2
Support the channel on Patreon:
/ adriansdigitalbasement
-- Tools
Deoxit D5:
amzn.to/2VvOKy1
store.caig.com/...
O-Ring Pick Set: (I use these to lift chips off boards)
amzn.to/3a9x54J
Elenco Electronics LP-560 Logic Probe:
amzn.to/2VrT5lW
Hakko FR301 Desoldering Iron:
amzn.to/2ye6xC0
Rigol DS1054Z Four Channel Oscilloscope:
www.rigolna.co...
Head Worn Magnifying Goggles / Dual Lens Flip-In Head Magnifier:
amzn.to/3adRbuy
TL866II Plus Chip Tester and EPROM programmer: (The MiniPro)
amzn.to/2wG4tlP
www.aliexpress...
TS100 Soldering Iron:
amzn.to/2K36dJ5
www.ebay.com/i...
EEVBlog 121GW Multimeter:
www.eevblog.co...
DSLogic Basic Logic Analyzer:
amzn.to/2RDSDQw
www.ebay.com/i...
Magnetic Screw Holder:
amzn.to/3b8LOhG
www.harborfrei...
Universal ZIP sockets: (clones, used on my ZIF-64 test machine)
www.ebay.com/i...
RetroTink 2X Upconverter: (to hook up something like a C64 to HDMI)
www.retrotink.com/
Plato (Clone) Side Cutters: (order five)
www.ebay.com/i...
Heat Sinks:
www.aliexpress...
Little squeezy bottles: (available elsewhere too)
amzn.to/3b8LOOI
--- Links
My GitHub repository:
github.com/mis...
Commodore Computer Club / Vancouver, WA - Portland, OR - PDX Commodore Users Group
www.commodorec...
--- Instructional videos
My video on damage-free chip removal:
• How to remove chips wi...
--- Music
Intro music and other tracks by:
Nathan Divino
@itsnathandivino

[@darkstatehk]

"I don't know what 2022 is gonna bring for me, I think there's potentially gonna be some changes in the future for me ....but I'm not gonna talk about that at this point....." *Adrian, ARE YOU OK? WE LOVE U SO MUCH! Hoping that your health is in good condition and your situation is positive.*

[@miken8150]

Spoiler: Adrian quits his day job and decides to do KZbin full time. 🤪

[@GManmcaoidh]

Changes? Hope everything is alright with you Adrian. Love what you do - hey even the lows are part of the adventure. It sucks, but it makes the victories sweeter.

[@robintst]

Weirdly though, the keys still being discolored actually still makes it look like a color scheme you would have expected a company to choose back then.

[@larrybud]

5:30, I actually did this upgrade to my original machine (1988-90ish?), but mine had spaces on the board for the extra ram. However, the traces were not complete, and I had to run a TON of wirewrap to every chip. Still to this day I can't believe it worked. It was a ratsnest of blue 30 gauge wire! Also, back then there was a RAM shortage and RAM got REALLY expensive. Remember, those chips are only 16k each. I think they were like 10-$12 each at one time. I also added a RTC to the board and wrote an assembly app that would automatically call out to the Naval Observatory on bootup to set the time in the early 90s. The RTC didn't have a battery, so it would otherwise reset on power down. That software is still out there in the "Crawly Crypt" archives that you can find online. Every once in a while someone would send me a check for 10 bucks to my parents old address for it. lol

[@mirlivaturab9078]

Good attempt for upgrading 512 KB old Atari ST 16bit computer to 4 MB. As i followed from this video it was a very detailed attempt, but as you are experiencing servicing (repairing,testing,upgrading),old and new computers , may be you have to ask the experience of the people who sent this 4 MB Atari ram to you or the other people who used this upgrade before you, or the manufacturer of this hardware could answer you , may be after they watch video of this upgrading attempt even they can't see the details of soldering and other workmanship in the video. The hardware tester software of Atari ST 512 showed the installed memory but there are not any other info about the computers' whole hardware which is a sign of possible loss which is causing this crashing. As a summary , Adrian, keep up the good work. Thank you for the informations.

[@blackterminal]

Agree retro bleach looks nicer but I'll never be convinced it doesn't at least in some way degrade the plastic and secondly that the yellow won't soon return

[@6581punk]

Bad solder joints can cause instability issues too.

[@pintokitkat]

I'm just going to stick this thing down here, I guess. Adrian turns into Jan Beta.

[@kaitlyn__L]

Aww, oh no! That sinking feeling of wasted time over a potentially simple check always sucks really hard.

[@DaT0nkee]

Remove the plastic spacer from the pins, and snip off 2 mm of the ends. You have extra 2mm if it is enough. Also install some pin sockets for the jump wires, and pins on the wires so you can remove it any time without soldering.

[@ZXRulezzz]

I don't think he can do that, those look like machined pins and not your standard 2.54 pin header, if you remove spacer from those you'd still have a thick part of the pin getting in the way. Those pins are really good and don't wreck sockets (round profile, smaller diameter, and nicely rounded end), but yes, have to watch the height if it's critical. I designed a TRS-80 model 100 RAM expansion a year or so ago which plugs into its system bus (the one under the cover on the back). I was going to use those machined pins and had to absolutely make sure it'll all fit (and it did). Since then I've been slacking off on writing software for it :P

[@suchkasuchka]

​@@ZXRulezzz seems like a good field for experimentation with different kinds of pins!

[@pANZERNOOb]

I second that, how exactly he extracts the spacers might be a bit tough tho. Maybe he could use pliers to carefully pull the plastic off without bending the pins, or maybe cut the plastic away. Honestly I think it might be best to remove some pins from the spacers before soldering them to the board, of course he would have to redo the pins on the expansion card.

[@keithw6379]

I was going to say the same. I can sometimes slide the plastic spacer off if it's only a few pins or sharp cutters can crack the plastic to release them. I then cut a piece of heatshrink to size and Drop it over each pin and cut it to the top of the heat shrink giving me a guide to get every pin the same height. You may find it harder to plug back in as the pins are tapered at the ends and you would have cut the taper off

[@techrev9999]

I was thinking the same. You do get the feeling he backed out more because of the instabilities than the fitment.

[@vonkruel]

Hey, you started with a working ST and you finished with a working ST. Anyway, I think there's real value in showing your mistakes, and it reflects well on you to do so. Your projects usually end well, and a "fail" here & there only makes the wins that much sweeter. Best wishes to you & your family sir.

[@timothywildschut]

Maybe you can fit it in, just get rid of the black plastic stand-offs on the pins? Perhaps that give's enough room for the keyboard to fit.

[@NoshAbroad]

this is exactly what I was thinking

[@blackterminal]

Destructive removal?

[@loughkb]

@ 29 minutes in the video, where the ram test had failed once at 4 M. I keep wondering about cross-talk between those long wire runs to your switch and the traces on the ram board. At the RF frequencies the machine is running, those signal lines can start to act like antennas. 8MHz, right? That's around 38 meters on the shortwave band, ha! If you have stability issues down the road, maybe move the switch to the other end of the ram board and shorten those wires on that address line. EDIT: I just got to where you discovered the keyboard doesn't fit. Damn! I felt your pain man. Crap. 2Nd Edit: take the plastic spacers off the pins and trim them all a mm or two?

[@kjtroj]

I will admit, while watching this, I was wondering "Will sockets make it too tall for the keyboard?" Sadly, it did. As someone suggested, you may be able to remove the spacers on the headers, clip the leads short and fit it in. All depends on how far off the fit is.

[@ItsMrAssholeToYou]

As soon as removing the RAM was brought up, I immediately thought sockets, then clearance. I figured he would had done the same, so when he started talking sockets, I presumed he checked the clearance before proceeding. I was kinda surprised when the KB didn't fit.

[@peteregan9750]

Adrian - really enjoy your videos... A quick tip, to remove all those sockets more easily, capsim tape around them, and protect the other areas , USE A HOT AIR GUN with a small wide nozzel and the sockets should just drop out if the board is raised off yhe bench.

[@Solitaire1]

Adrian, can you cut the pins shorter then pull off the plastic bits from them? That would allow the board to rest right on top of the sockets instead of standing up so high. Since the original chips fit under the keyboard while in sockets I would imagine the board could too. It did not appear to be any thicker than an original chip from what I could see.

[@TheThomasites]

Came here to say this. It could work.

[@lauram5905]

You could also insert them from the top, solder them from the bottom, and then cut the exposed top pin off to prevent shorting out. Alignment would be A LOT harder I think like that, but you’d get a much more flush installation

[@akkudakkupl]

The git repository explicitly said to solder the board directly, unfortunately a case of rtfm 😕

[@IanSlothieRolfe]

The turned pin headers he has used have a wider section that is moulded into the plastic so you can't do that. The only real alternative is to remove them and solder in .5mm bronze wire that will go into the sockets. That way the total height will be roughly the same as the DIP chips. That's quite a lot of work however.....

@@akkudakkupl if you rtfc(omments), you'd have noticed that the github page was updated with that info due to this video.

[@stubarnes1965]

I remember modding my 520 as you describe back in the day. Chips soldered directly to the original bank with ras and cas bent up 180 degrees to run a pair of bus bars along the top set. Worked perfectly for years.

[@bdeblier]

That was how the 520ST+ came out of the factory, IIRC.

[@virtualtools_3021]

Half pcb, half deadbug, epic!

[@Ray-ds5dc]

Yes, I did the same to my 520 STFM and it seemed to work well. I used cheap second-hand memory chips (from a UK main-frame scrapping company) and followed directions in a magazine (early 1990s).

[@joefish6091]

@@Ray-ds5dc Happy Memory Essex ?

[@winfel]

I always appreciate videos about the Atari ST. However, I am always puzzled that in the US and in the UK, it is always seen as a games machine and therefore alway is a bad machine compared to the amiga, while here in Germany, it was almost exclusively sold with the great monochrome monitor and was seen as a better and far less expensive Macintosh-like machine. This can also clearly be seen in the German commercial about it. Here is one from 1986 kzbin.info/www/bejne/iXq1aYd9rpxsfMk and another one from 1988 kzbin.info/www/bejne/i6jHq6p8a5psrKs. In the latter they say (a little roughly translated) "Atari Computer, that is high tech from today. With extensive software for all areas. In professional use, in science and technology. As text and information systems in modern offices. For ambitious tasks in the private area. Getting on it and understand. That is computer technology to perform better. Atari, we make top notch technology priceworthy."

[@FoxbatStargazer]

My family had both monochrome and color monitors. Word processing and faffing with midi keyboards was great on the mono. But it was 95% playing games on the color or a TV. Then again we were kids...

[@myfarawaytales]

I went from Spectrum 128k+2 to Amiga 500. The only Atari I owned was a 2600

[@scottlarson1548]

The magazine ads in the U.S. always compared it to the Macintosh.

[@KolliRail]

So true!

[@amirpourghoureiyan1637]

It comes down to the fact that it was Atari branded and had an extensive games library. I doubt it would be judged the same if it was an Osbourne or Eagle computer.

[@BrainSlugs83]

I believe the reason your getting non-deterministic issues is because grounding that address line isn't doing what you think it's doing. It does disable the upper memory. But, it also remaps the upper addresses to the lower addresses. Think about it, if the Atari tries to write byte at a high address, with that bit of the address line grounded, it's still going to enable the lower chips instead, thus overwriting that memory. This will even fool the system test, when it checks if those upper addresses can be written to and read from, it will pass that test and think it has 4mb, even though that line is grounded. -- This is why the flakey behavior is event based (opening a program or changing a setting, etc.) If you really want a physical switch that will disable half the RAM, you'll need a logic gate (or a diode) that takes the /CE lines high when that high bit is set. Games are working because they aren't using that upper memory.

[@horusfalcon]

Nice catch! I do believe you're right.

[@UnseenMenace]

Wouldn't just disconnecting A9 be sufficient? After all, the A9 pin on the MMU wasn't connected to anything initially.

[@tekvax01]

@@UnseenMenace No! you must remove the CE {BAR} signal as well.

[@markpstapley]

Hmm... I also think you are spot on with this. Also think he should disolder the pin headers from the add on board, and get replacement ones of the correct length, rather than trying to cut down the existing ones to try to make them fit.

[@charlieb9502]

You live and you learn, Still a great video. Think about it. You just saved the others that would have done the same thing the frustration and possibly in the process of removing the sockets rip out a via or damage the board and not know how to trouble shoot it like you can. Still a Job well done!

[@thegrays3303]

This brings back memories. I started my computer knowledge back when i had a TI-99/4A home computer which my parents bought for me . I remember when I got my first floppy disk for Christmas. When I got the 32K RAM memory expansion for it I I was so happy.

[@subtledemisefox]

My first computer was an old Packard Bell with Windows 3.1 installed on it, but in my teenage years I read all kinds of books, programming manuals, etc. for all these old computers for fun. One of my favorites was one that had BASIC text adventure games for the TRS-80. It had some kind of robot as a mascot for it, iirc

[@john_ace]

I have used tinned wire instead of pins in these situations. I would take the most tight fitting diameter (0.5mm) and feed it through the holes of the pcbs directly into the sockets below. The wire then gets cut with a generous margin and soldered afterwards. When the wires are soldered, you will have a very close fitting pcb with pins in the perfect length. I made a shrink dip 64 -> dip 64 adapter for a 68k cpu that way. It was only slightly taller than the original. Sometimes you have to get creative ;-)

[@IvorySoul696]

Dude, that Atari I donated is STILL making videos! So freaking cool. I keep getting surprised that this was a deep rabbit hole in the end. I never would have guessed just peeking under the hood. Hopefully, the changes are positive. I know you've been struggling with formatting for the last couple of years.

[@anonymouse-f4z]

what you can test is to remove the black spacers on the expansion board and shorten the pins to see if it fits under the keyboard.

[@granlund23]

Great to see that it's working, and good idea with that switch :) "Oh no..." was my reaction when you got to the part where you mentioned socketing the thing - and immediately regretted not mentioning keyboard clearance. I have updated the readme for the project on Github to specifically say not to use sockets. So, for what it's worth, big thank you for the contribution. Even if it was a bit of a fail right now for your machine I think the video itself is a success! It was fun watching it (and very relatable because I think we've all ended up in quite similar situations at some points, I certainly have :) ) I'm sure this video will be super helpful for anyone else who attempts to install the thing. About your machines random issues, I too would suspect the power or noisy signals. These machines can be a bit flakey.

[@blackterminal]

Which are flakey? Any ST or the early version here?

[@3vi1J]

Well, there's a lesson to be learned in everything. The lesson this time is "quadruple-check clearances when adding sockets. ESPECIALLY when stacking mods on them, and ESPECIALLY when they are located near the lower part of the case where there's less space below the keyboard." Still a great video, as usual.

[@Otakunopodcast]

Trust me, you do NOT want one of those desoldering stations with the external suction. All of the ones I've tried (and I've tried a great many of them) have very poor suction, which results in frequent clogging. I would say "they really suck" but in this case "they really don't suck" is more appropriate... which normally would be a good thing, but not in this case! ;-)

[@mal2ksc]

Like Butt-Head once said, "We need a woman that doesn't suck. No, wait, that's not right."

[@gregcoons7308]

Dang that stinks about the fitment with the keyboard....I think I voted for the sockets. I vote for more Atari!!!

[@Renville80]

What if you were to take off the insulating spacers off the pins and trim a corresponding amount off the pins themselves to make the RAM mod lower profile?

[@gaming_coffeebean]

Love your vids keep up the good work. :)

[@gregwtmtno5437]

Adrian, I don't usually comment, but I want you to know how much I love your videos--but also, make whatever changes are best for you. Sometimes I see the amount of work you do and wonder how it could be possible. So I guess, take it easy, and don't become another KZbin burnout.

[@WalterFrancis]

Warning your users of such a thing: Failed successfully. It's all about the journey Adrian, glad you showed us this, you could have pretended it never happened. :D

[@moo4983]

One of the first (successful) soldering jobs I ever did involved expanding the RAM on a piece of audio equipment in preparation for replacing its ROM with a more feature-packed one. I had to clear some unpopulated spaces for 4164 RAM chips, and the best idea I had at the time was using an aluminium paper clip to push through the hole as I heated it with the iron. Amazingly I didn't damage anything and the whole thing was a success (though I dread to open it up and check my work).

[@R.Daneel]

Good job! Reminds me of a low-tech "desoldering" kit you can ebay. Basically a set of paperclip sized hollow tubes on handles. You heat up the join and push the aluminum tube over the pin. The solder sets, but doesn't stick to the aluminum. A bit slow, but I use them for fussy pins now and then. Edit: I found them really good if you were having trouble with solder on the front of a board that you couldn't reach, and just wouldn't budge. I bet with care, they may be good for protecting weak traces too as there's no suction or adhered wick.

[@andrewmorton9683]

@@R.Daneel FWIW, desoldering needles are usually made from stainless steel (my $4 set is) as solder does not stick to that, and aluminium is likely to be a bit fragile for thin tubes like that.

[@weasel2htm]

Remember, you just WON at showing your viewers a potential pitfall with this upgrade. Take a break from it and next thing you know, you'll be ready to yank those sockets out and solder the expander right to the board.

[@letthetunesflow]

Oh man, watching this episode and instantly noticing the potential keyboard fitment issue caused me to start 😱 screaming in my mind! I noticed instantly that those sockets were potentially going to cause problems, it was both frustrating and entertaining all at the same time! Really enjoyed this episode tho! I really think you should just make a little wire harness for the ram upgrade! That would allow you to switch between the original ram and the upgrade quite easily! Just add some pin and socket leads like how PC’s have PC speakers and power switch sockets and plugs! What do you think about that idea Adrian? Fellow viewers what do you think? Would it be worth the effort? It would just allow you to have an easy plug and play option to easily switch between the original ram, the ram upgrade, along with still having the switch between the 1&4 megs? You would just need to find socket pins to attach to the homemade wire harness and some pin sockets in a few areas? I hope this idea makes sense! What does everyone else think of the idea? Looking forward to what the new year has in store for you Adrian! You have one of my favourite channels, along with one of the nicest and warmest hearts on all of KZbin! My health hasn’t been good enough to support my favourite KZbinr’s, like yourself on Patreon, as I’m sadly on disability, but I’m hoping in the new year that it will be possible as my health has started to improve! It would be such an honour to support you when I am able to! Please don’t stop making such amazing videos! Your passion and love for retro computers is so inspiring and lifts my spirits every time I’m having a bad day! It helps distract myself from the agonizing pain I’ve been in! Thank you soooo “Freaking Much!”!!!!! 💻 ❤️ 🙏 ❤️ 💻

[@scottharris7222]

This is one of those efforts that just needs a short break. I was wondering at the beginning if you had done a dry fit. Regardless, showing us some of the set backs is as important as showing us the victories. This modification will come back stronger after you take a break from it and we'll all be better off for your experience. I love the passion and I can feel the pain when something doesn't work out. I love that you keep it real.

[@androxilogin]

Ohh man.. My first thought with this upgrade was how the keyboard would fit. I disregarded it by figuring the manufacturer would have had this all ironed out. My second thought was, "I'd use sockets. Oh good, he did". Apparently I'd have made the same mistake along the way.

[@ZoruaZorroark]

i have to say that the two-tone of the keyboard actually looks kinda nice, and still pretty darn cool on what it takes to upgrade any vintage computer like what you have done with your atari

[@andenmcleod7355]

Hello , I was wandering if you know what type of power supply a Compaq Presario cdr 972 uses? it has two connectors on the plane board an 11pin and an 8 pin do you know what it uses? if I can't find the psu type i might have to throw away this 1994 compaq. this desktop has an AMD am486 DX4-100 cpu. The assembly number is 004149-001 rev d. Diagram number is 004150. its fcc id is CNT75MDCZC4 its a SERIES 3520C4

[@colindevaux4476]

remove the black plastic bits off the pins.maybe cut the pins down too?

[@NoshAbroad]

up vote for awareness

[@Potts1966]

That's a very cool upgrade, shame about the keyboard not fitting. I did a couple of RAM upgrades to ST's back in the 80's and early 90's. Each one was a 2MB upgrade but kept the original RAM intact to give 2.5MB total. And I remember being very nervous about pushing the board onto the MMU, but it all worked really well. There was also a couple of flying leads to add and small grabbers were used which attached to the pins on a couple of chips., but no tracks to cut or anything to solder.

[@Sir_Uncle_Ned]

Good idea putting in those sockets. Since you were removing all those chips anyway, may as chuck in some sockets to make reversing this if required easier. EDIT: Damn tolerances.

[@SegHaxx]

tbh as a long time Atari ST user, the original 520STs were infamous for being just a little bit temperamental. even without a RAM upgrade jiggle it a bit until it works. they're just like that

[@richardpowell5653]

It's really not a fail mate. It's a triumph in knowledge sharing! Anyone doing electronics has been there and experienced the cold chill that runs down your spine when you see things have not gone as well as expected... love your continent dude... I'm wondering about my st2 mega that I want to upgrade, maybe just buy sockets and a bag of ICs...

[@theshuff]

You should try to remove black pastic spacers on the pin, trim them a bit, and plug the extension back.

[@paulodagraca3469]

Adrian, back in the day (around 1989) we would do lot's of ram upgrades. If i remember right, with instable computers we would insert a 33 Ohm resistor on each line of cas, ras. Reason would be the noise on the longer cables and found that it would be best to have the resistors as close the ram as possible (end of cable). So at the end of the wires we would shorten the wires and connect the resistor to the wire and ram, and use heatshrink for isolation. I think it was because we found that the 5 volt on the pins would go up to 6 volt spikes on rare occasions and the resistor would help reduce this voltage, resolving the problem. Hope this could work for you as well. Kind regards ( always love your content ).

[@educatedoaf]

Lower profile pins should work fine and be the easiest fix.

[@MrDarchangelomni]

uh how hard would it be to remove the black plastic from each pair of pins and snip half of each pin off, shortening the pins, then the board would lay right on top of the sockets? lmao just saw that the most liked comment, said the same thing :) great minds and all that.

[@johntilghman]

Would a hot air reflow tool make this any easier? I have the Atari 1040 ST do I have any options for memory upgrades?

[@PaulsComputerEmp]

Might be worth trying alternate TOS, if it runs unstable super lucky you didn't solder to board.

[@goddessesstartrekonlinefle3061]

I thought it might be the TOS version as well, I seem to recall the first release of TOS had issues with memory management, though after all these years my only clear recall is TOS 1.02 was the TOS of choice for gaming hehe.

[@Evhen_Velikiy]

Hey Adrian! Don't remove sockets. Just use short pins for red PCB. Its will be just fine!

[@OldCircuitGaming]

i have 5 different ST's in storage and i think at least 3 have ram expansion, i actually bought a storage container of Atari stuff just to get my hands on a colour monitor.

[@goddessesstartrekonlinefle3061]

Thanks for sharing your adventures in electronics ^^. Wishing you the best of successes for 2022 :).

[@stompreaper]

I really felt your disappointment Adrian but it was a worthwhile journey. Thanks for sharing.

[@kittyztigerz]

U removed low profile pin n put stand off pin make ur day worse Try put back on low profile pin im sure u will get it back together

[@a4000t]

The nightmare of st ram expansion makes me appreciate the Amiga's ease of ram expanding.

[@tjlazer71]

In the 520STE they got it right with four 30 pin SIMMs for 4MB total.

[@a4000t]

@@tjlazer71 4mb lol.

[@tjlazer71]

@@a4000t what’s funny? Much better than what the Amiga 500 or 1200 could do internally. Having four SIMM slots on the motherboard was really amazing at the time. Try adding 4MB to the 500 at the time. Much harder and more expensive. The 1200 has the trapdoor slot which was nice but more expensive to add memory. But of course a lot better if you wanted to add a CPU card and memory. But you know all this because you’re a Amiga 4000 fan. As am I.

[@a4000t]

@@tjlazer71 most Atari stuff was somewhat crippled. I would always opt for the machine with max expandability. That being said i was always a fan of big box amigas.

[@phillipzx3754]

The original 520's had openings for the added RAM. As many now know, the early 520 was just a 1040 with 16 empty DIN locations. I modded hundreds of them for people prior to Atari changing the motherboard to the version shown in this video. I still have two ADAP samplers I bought from Hybrid Arts.

[@Okurka.]

Which DIN locations?

[@VK2FVAX]

We've all had these sort of moments. At least it wasn't on something worthwhile like a Commodore system. (/me waits for the hissing to start).

[@JonathanZigler]

Dip switch could have been fine and shorter sockets.

[@thomasives7560]

Hey Adrian, thanks so much for sharing. Even in disappointment there is learning - you've saved someone (or several someones) out there in the community a lot of frustration and rework - so, major thanks for your contribution! Have a Happy Holiday and I look forward to many more of your entertaining and informative videos. Cheers! p.s.: Did this kind of stuff way back in the late 80s working at the University of Oregon Bookstore Computer Shop (Hi John and Mark if you're still around!). Upgraded a lot of customer 520s and fixed a lot of defunct switching power supplies (the *bane* of my existence). I'm really glad to know this hardware is still working and bringing joy, I really had a lot of fun in that scene during the period.

[@Vanders456]

I'm always surprised that Atari created a bunch of custom chips that could support more RAM than was onboard and didn't break the signals out into a connector or header, or even a set of vias on the board to add a connector.

[@capitanschetttino8745]

The important thing in this video is good work practices. The computer remains in excellent condition and now it is much easier to replace a ram chip.

[@10p6]

Nice video. 7 Years later Atari was still creating fun with RAM, this time on the Falcon as the Memory board connectors are two different heights, yet some third party RAM board creators did not take this into account, so the board could short against the RF Shield.

[@loughkb]

This brought back memories. (no pun intended) I remember doubling the memory on my Amiga 1000 by piggy backing RAM chips and wiring on address line from them down to the board. Those days were all about hacking things in. It was real back then! So to speak. Ha.

[@pc-sound-legacy]

4MB for a 520ST, if someone told me that back in the days😄 The switch is a great idea👍

[@altgenesis]

I waited for the 1040ST. I still have it and the monitor and a hard drive as well. Still works. My Grandchild came over and played games on it quite often. Got it boxed up. 1 meg of memory. Woohoo. Still remember being on the dial up ST Boards and going to the Mug Clubs. Plugged it into my stereo with the 3D sound which was just three audio plugs and converted it to 2 and plugged in the TV and voila played driving games on the TV with the nice 3D stereo sound 17Hz to 22kHz Polk speakers. Awesome. Also had a 24 dpi pin printer. The early days of computing with a mouse. Eat your heart out Apple.

[@jonatas464]

How about to verify the amount of energy consumption? When you put into 4MB, I think the consumption increase. Maybe the track is to tick? Maybe the energy supply isn't sufficient... I don't know... I'm just wondering...

[@dexteria3467]

you can try breaking the black plastic of the stand off pins you've installed on the memory upgrade so the pin can be pushed down more into the memory sockets ...that may help the memory upgrade board back rest directly on top of the memory sockets you've installed

[@NoshAbroad]

upvoting for awareness. I was thinking this too

[@thomasquemar969]

Hi, just pull off the plastic spacers on the back of the expansion board (pull each of them with a flat screwdriver or anything similar)! Then short the legs in order to be able to make the expansion board as close to the main board as possible ;)

[@thomasquemar969]

Someone said : "if you remove spacer from those you'd still have a thick part of the pin getting in the way". In this case I suggest you remove all the pins from your expansion board and replace them with constant diameter pins (hard to do but worth it I think).

[@mannycarrion7862]

Wow its like a vampire cards taps into the CPU kool

[@linksmith1057]

Adrian, don’t beat yourself up too much. My first thought after you removed all those original RAM chips was that you should install sockets.

[@hjalfi]

There are mini desktop cases for Amigas, turning them from all-in-one units to system-box-and-external-keyboard units. Can you get them for Atari STs too?

[@ChristianMadriaHansen]

Just cut the pins short and remove the plastik.

[@byronwatkins2565]

Gain of field effect transistors increases as they warm up. I predict that your timing constraints are borderline and easier met as the transistors get faster. I would remove those black plastic separators, clip the leads shorter and see whether they fit then.

[@NoshAbroad]

I was thinking this also. it should make the difference

[@Cherijo78]

Thank you for this! I appreciate seeing this accidental fail a lot. It's a great reminder of checking clearance in these tighter packed machines! Thank you!

[@rubygupta9770]

Maybe you can remove the little plastic seperator thingies from the connectors and cut the connectors short. That would probably provide some clearance

[@RickMacmurchie]

Pull the black plastic bits that keep the pins aligned off or the ram board, (they will slide off, they are just friction fit) then you can trim the pins and you can probably get the board to sit about 1/8" lower, if that would allow it to fit.

[@wimwiddershins]

Yeh, I was thinking the same thing. I did this with a PiStorm, worked fine.

[@NoshAbroad]

this was my first thought

[@watchmakerful]

The cause of errors is often very simple: all lines from the MMU to the memory chips should have the same length.

[@ickipoo]

Might be worth putting the scope on that 5V rail - 4.8V is pretty marginal, and bad filter caps can manifest that way - the voltmeter will show something like an average, and bad filter caps may mean much deeper dips. I had scary issue with the buck regulator in an ethernet switch - I measured the logic rail at 5V with my multimeter and thought it was fine, but put the scope on it anyway. Turns out it was actually supposed to be a 3.3V rail derived from the 48V PoE supply, but the filter cap had dried up completely - what the multimeter reported as "5V'" was actually narrow spikes of 48V! Incredibly, all the logic survived.

[@ZeddProphecy]

Had Every Atari from the 400 through the Mega ST - with how much that board was jostled try reseating the chips *not yours - those sockets are sub par and notorius for on screen bomb errors - My local Atari dealer would advise people to lift up the 520 about 2 inches and drop it - no kidding. This generally worked until successive drops would crack the board.

[@LazyBunnyKiera]

Adrian, the pins.. can you just just some flush cutters and trim 2-3mm off each pin and push the black header"holder" things down so it sits more flush with the red ram pcb? I see absolutely no reason why you couldn't do that. Between the shorter pins and the header holders pushed flush, you should be able to seat the red ram PCB at least 3-4mm further down. Which might just be enough.

[@ScoopexUs]

I've owned a Spectrum and an Atari ST. Luckily, the store took them back. It's simply crazy to assume that users won't want to expand their RAM. Don't think we're done with cheap stuff either, Apple does this today. Cheap. Being old doesn't save it, Tramiel forced his engineers to do a bad job, and this is horrible for a 1985 computer. The reason then was as today: to force you to buy a new computer, just because you need more RAM. There are no limits for a CPU or motherboard to populate its maximum RAM, except for decisions made by non-engineers; amateurs. I'm sorry for the strong reaction, you did your best to get more RAM and to do it, you had to turn your computer into Frankenstein's Monster. It's just so sad to see. Learn the lesson. Don't buy a computer you can't expand.

[@lucasjokiel]

I was already screaming NOOO, don't put the sockets, then Adrian, you added a switch! Darn, why I had not written about my concern after last video :(

[@uni-byte]

I too upped my 520ST to 1024KB using the piggyback method. There were no commercial kits available back then (Christmas '85) and the 1040ST was too much money. 4MB would have been awesome back then (and unheard of!) I would just solder that 4MB expansion directly in. It would not be irreversible and would be much more reliable.

[@geoffmolyneux9173]

My original Atari 520ST had its 1meg upgrade. The person bent all the new ram chips so they came to top. Then the chips were soldered to the bottom of of the mother board on existing ram chips pads. With wires ran for ras, cas.

[@charlesjmouse]

Aww... A thought, for when you can be bothered: Leave the sockets, desolder the pins from the RAM board (again), and lay it over the sockets. Then push some thicker wire saved from passive components through the holes in to the sockets.* Then solder the wires sticking through the RAM board and cut flush. You should have clearance for that 4Mb board without having to desolder the sockets. But NEVER try to pull the RAM board, you won't get it back in!* *This trick works best with turn-pin sockets but is doable with the wipe type if that's what you used, just be very careful to make sure the wire went strait in! Also be sure to put some insulation tape of some kind under the PCB if you're not using turn-pin sockets to prevent shorts. (pre-poke the holes!) Um, too much solder will wick down the wire to the sockets and make a permanent connection - good if that's what you want, very bad if not! The same can be done better with some wire wrap socket pins or similar, if you can find any! Being proper pins they will be robust enough that should you ever remove the RAM board it will go back in later. At a pinch you can sand square header pins round-ish to fit sockets by rolling them in wet 'n dry paper, but it takes patience to do right. How do I know this? If you own a BBC Micro with internal socketed boards that need repairs, or have designed a few upgrade PCBs for old computers that have to fit in tight spaces you have to get very creative! I hope that helps.

[@epremeaux]

pull all the black plastic spacers off the header pins, then either cut the pins short or hit them with the soldering iron to slide the pins up. get the red board right down on the sockets and it might fit

[@NoshAbroad]

yup! I had the same thought

[@jarnailbrar6732]

I remember my 520ST, it didn't even have the TOS ROMs, had to load TOS from disk. Later installed the TOS ROMs, to free up (192KB?) RAM. Might have done the piggyback upgrade to 1MB. Purchased Mega ST4 with built-in SCSI hard disk after that. Thanks for this great video.

[@clangerbasher]

I only have 3MB in mine and it does limit real world operations.

[@corkymork]

Oops. Maybe you could reduce the profile enough to make the mod fit if you are able to remove the black spacers on the headers. Usually they can just slide off, though you might need to desolder the pins from the mod.

[@williamsquires3070]

One simple thing you can try before going all ballistic on it, is to remove the little plastic bits on those pin headers; just make sure to lift them off perfectly perpendicular to the board so you don’t bend the pins. Then, measure the length of an IC pin from any of the RAM chips you removed, and cut all the pins on the bottom of the RAM expansion board to that length. You’ll still have to mount the toggle switch elsewhere, but the keyboard should now clear the RAM expansion board, now that it’s (roughly) the same height as a 16-pin DIP IC! HTH! 😍

[@LeftoverBeefcake]

This channel always gets an automatic thumbs up, rain or shine, success or fail. There's always something to learn, which counts as a win in my book, even if it's learning the hard way. :)

[@error079]

Make the keyboard external

[@DeadCat-42]

I have an old 520 stfm MB that i damaged as a teen soldering in a 16 MGHz accelerator card with a cheap radio shack soldering Iron, so i put my ST back to original and am now making a Fankintari out of it with every mod I can find. I got the accelerator board in and it runs, it has a socket for a blitter so I'm going to look for one and then try a PIstorm on top. I have 2.5 MB of RAM mod , a tweety board and a few other things, it's in an old PC case but I'm thinking of 3D printing a new case for it. I had a broken ST mouse I turned into an atari compatible laser mouse with the guts of another mouse and a little circuit .

[@drxym]

The difference in out of the box expansion potential between an ST and an A500 is pretty significant. ST - solder this, cut that, bridge this. A500 - open hatch, plug in board.

[@eformance]

The length and routing of your bodge wires, and ESPECIALLY the toggle switch, give me reason for concern. You ran the address line through a "dirty" switch and added a bunch of length to it. You need to consider the bodges like traces on the motherboard, they should be as short as possible and routed in a similar path as the factory traces. I have doubts the toggle would be reliable over time, since that line will probably suffer from signal degradation due to length, etc.

[@tucsonsduke]

I've only been watching you for a few months, but watching how you handle failure and disappointment is inspiring, and I'm glad you still include those moments in your videos.

[@KolliRail]

Well, that's sad... Some things to know: The mouse requires the keyboard processor for operation. And that sits on the keyboard pcb. There is nearly no software that won't work with 4 MB. The few games that didn't back then are now available in patched versions. And there are at least 2 solutions for upgrading to 4 MB that go another way. They plug in under the shifter and connect the address lines and RAS/CAS with wires. Both from Germany, both around € 30. And the ST will also work in ST high resolution with the correct cable and a VGA monitor or the VGA input of the OSSC.

[@donwald3436]

Instead of making a MMU vampire board, why didn't the board have the installer move the MMU chip above the board, just like the Shifter chip intercept board? It can't be too small pin pitch, the vampire board is the same pin pitch. Were PLCC chip pullers that expensive?

[@benjammin1001]

Just an FYI -- to say the ST is a "16bit machine" is an inaccuracy worthy of note... The 68000 family is a 32bit CPU, but with the 68000 package, the data bus is 16bits to save pins. I like to make the distinction because people will walk away thinking the ST is a fully 16bit machine like maybe the 65C816 has the capability for. Some might argue semantics. But, I think following, "The devil is in the details" -- it's always best to be as accurate as possible. I design electronics for clients as a consultant and non-specificity is one of the hardest things to overcome with some of my clients. Their language in general tends to be nebulous... so I can't be. And it becomes habit... but it also averts a lot of issues. (especially since I'm not a mind-reader.) just a thought.