You won't believe why the sound was broken on the Color Classic!

This is final part to the Mac Color Classic series. In this video I solve the mysterious issue with the sound and then put the Color Classic through its paces with some software.
Part 1: • Can I save this Macint...
Part 2: • The Mac Color Classic ...
Part 3: • One fast Macintosh Col...
Part 4: This part!
--- Video Links
Macintosh Color Classic
en.wikipedia.o...
Macintosh LC 575: (Mystic Upgrade)
everymac.com/s...
The Power Color Classic Resource
powercc.org/
--- Tools
Deoxit D5:
amzn.to/2VvOKy1
store.caig.com/...
Jonard Tools EX-2 Chip Extractor:
amzn.to/2VazxDS
www.jonard.com...
Wiha Chip Lifter:
amzn.to/3a9ftWw
www.wihatools....
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
Outro Music:
Abyss by | e s c p | escp-music.ban...
Music promoted by www.free-stock...
Attribution 4.0 International (CC BY 4.0)
creativecommon...

[@ropersonline]

This feels like nothing but divine retribution for serial RF-shield snubber Adrian.

[@dw_2005]

I love this joke "Just to recap, I recapped the motherboard!!!"

[@frankowalker4662]

He Re-capped the Re-cap. :)

[@Charlesb88]

@@frankowalker4662 and now you’ve recapped a recap of a recap of recap which I have just recapped. Since this can go on forever I suggest we now put a cap on this conversion.😃

[@frankowalker4662]

@@Charlesb88 LOL.

[@isaacposselt7089]

This joke will scar me for the rest of my life, JUST TO RECAP. You have to recap right? It's food, I mean for the motherboard; I guess 🤷

[@BrainSlugs83]

Every time you remove an RF shield, I struggle... Like, they actually perform a function (not just using them for grounding and this kind of weirdness), but also, they block RF emissions (which can screw with cell phone, Wi-Fi, and Bluetooth reception, among other things). Like even if it has no RF specific components inside, some of those old CPUs and ASICs can generate radio noise, and noisy power rails can act as antennas. It's part of why they have those RF shields in the first place...

[@UnreasonableSteve]

Exactly! His I'll will towards shielding will probably bite back in much more subtle ways than just grounding issues. I guess I have to hope he lives out in the middle of nowhere

[@undefinednan7096]

Don't forget the other way around. Noise can screw with circuitry, especially analog circuitry, but by no means is digital circuitry immune.

[@Fifury161]

15:30 - Split ground planes are to prevent digital logic ground currents from contaminating the lower level analogue circuitry...

[@nickwallette6201]

Commenting to raise this. It’s pretty common to keep analog and digital grounds separated except for some central star ground point. Think of a PC case, for example. The whole case is grounded to the PSU. The motherboard grounds to the case via the screw posts. Drives ground their chassis via metal to metal contact to the case. The Pro Audio Spectrum 16 sound card uses the ISA bracket for its audio ground. (I found this out when I removed the bracket after replacing old corroded jacks with new ones that were slightly shorter.)

[@SianaGearz]

@@nickwallette6201 I weep when i see modern ATX enclosure front panels connect audio ground and USB ground together. When you get interference from increased load, no surprise. The mainboards are remarkably careful about star-grounding the audio unit today.

[@robiniddon7582]

Using the shield as the return path is not very clever though. It creates an enormous loop for the high impedance and noise sensitive audio signals. Audio frequencies are so low that they don't cause a problem for RFI so it's not necessarily a problem to involve the shield in the audio circuit. Until some other RF signal decides it would like to join in 😂

[@SuperMoleRetro]

I wonder what Adrian does for a living? He is so knowledgeable and hardly ever seems to get completely stumped.

[@MOS6582]

Dunno but pretty sure he’d be the guy that every tech related workplace has who deliberately keeps really quiet about how much he really knows otherwise he’d be swamped with requests to fix shit (on his own time and with no extra duties pay ofc)

[@daxx77m]

I got a feeling that he’s an electrical engineer or graphic designer like his dad

[@nickwallette6201]

Hasn’t he said before that he’s in IT? He just has really good troubleshooting skills.

[@SuperMoleRetro]

Yeah, electrical engineer was my guess.

[@360alaska6]

That’s cool! I designed that back panel and posted it on 68kmla.

[@RikerJoe]

I’m currently restoring my old Color Classic, and I’m looking forward to the day when I can say, “It works! It freaking works!”

[@retropcdurham]

It was only a matter of time before an RF shield got its revenge on you

[@erinwiebe7026]

@Adrian It's interesting to hear you reflecting on these compact Mac's. My SE Superdrive was the computer that got me through university and I remember loading up Netscape & Z-Term and getting it online for the first time. It had a 68000 16Mz accelerator in it but was still unbearably slow. Even Maelstrom was sometimes my game of choice to distract me from the all those papers I wrote on that little Mac. A colour classic would have been my dream setup too, and thanks to your channel I have a Color Classic II on its way to me right now from a Japanese auction website. Who knows if it will work or even survive the journey, but all I know that I need to get it out of my system and find out. If I can eventually coax Maelstrom to work on it then that will bring some nice closure too. :)

[@charlesconto3154]

Did you get your Color Classic running?

[@InitialiseDisk]

How did it go?

[@Retrocatone]

The RF shield revenge! Very surprise about the main cause of non working internal audio. Excellent serie, great job of restauration/troubleshooting for a wonderful machine at the end. I’m waiting for the next série now lol

[@tommythorn]

I never owned a Macintosh classic until a few years ago (now have Classic, Classic 2, and SE/30). Really love the compactness and the HANDLE! First time seeing the Color Classic 2 in action; while I'm not a fan of the case changes, the colors do make a tremendous difference. Nice job on the restoration, glad you stuck it out until the end!

[@DeadReckon]

That jelly donut shirt cracks me up every time... I only found your channel a few months ago, not big into Macs but I like that people restore these old computers, my elementary school had a few older units knocking around when they got the newer G3's. That startup "bong" always reminds me of sneaking off somewhere during lunch to play the Mac version of SimAnt or something on one of the older color Mac's they had around.

[@macdaniel6029]

Adrian got 0wn3d by RF shield. I love this sweet irony ^^

[@WelcomeToMarkintosh]

Wow-THAT is CRAZY! So cool you figured that out!

[@enzofitzhume7320]

RF shields are important. Example; my C128's RF shield doubles as on large heat sink! They are very important in Apple Color Classics. Concerning that Apple didn't use a ground cable!! Great video Adrian!

[@Wallygjs]

Adrian, glad to see you finally fix the sound issue. Like others below I had a chortle when it was the RF Shielding :)

[@Jimblefy]

Hello from the future. This was a great fix of a great looking mac. Thanks

[@no1leader135]

WARNING: Do never ever remove a RF shield from a motherboard. Sometimes it's sounds bad. ;-) Thank you for this another amazing video.

[@dionelr]

Woah! Maelstrom! I completely forgot about that game. We used to play in middle school.

[@JosiahGould]

We had an old Mac when I was in elementary school. It eventually got raffled off, and I lost. I was devastated. The "rich kid" got it. I would have loved getting it, but I hope Ben got some good use out of it. Love your videos. Thanks for the updates.

[@gusbert]

I've done many designs where single point grounding was used on a PCB (star point) especially when using high speed ADCs, but it seems like bad design to rely on external mechanical ground connections for a circuit to work. Perhaps this was the only way to get the board to pass FCC testing - sometimes when a product fails a test you get desperate!

[@z80dad61]

Bad design practice / 90s + apple engineering seem to go hand in hand

[@undefinednan7096]

Adrian, Apple did not split the analog ground plane from the digital ground plane to reduce EMI. Splitting the ground planes is a standard tactic to reduce noise in the analog circuitry for several reasons(*). When digital circuitry switches, especially CMOS, it will briefly draw a much larger "gulp" of current to switch voltages (needs to charge/discharge various capacitances). Because of ohm's law and the fact that real ground planes have nonzero impedance, this will actually produce a voltage spike on the parts of the ground plane the current flows through, which screws with all circuitry, but especially analog circuitry -- digital circuitry is somewhat protected by noise margins on logic levels. This is mitigated to a certain extent by bypass capacitors, which essentially spread the current spikes over a longer period of time -- the same amount of current will eventually need to flow in order to recharge the bypass caps. However, the current flow from digital circuitry still tends to produce noise on analog circuitry. Splitting the ground planes forces the return currents from the analog and digital circuitry to take completely different paths (**). Usually, the ground planes will be connected on the PCB, perhaps at a "star ground", but using the chassis or RF shielding is not terribly uncommon. * Note that this sort of design gets very complicated and there are disagreements about when to or if one should use split ground planes. However, my goal is to just explain why they were used here, not talk about what should be done for new designs. Please don't take this as advice on how to design PCBs. ** Note: modern sources advocate analyzing return paths instead of blindly splitting planes.

[@CrkdLtrN]

Hi Adrian, love your channel. You mention different parts for your videos at the beginning. KZbin does a great job of suggesting the parts in order if it's part of the title. Something to consider if you can do that. I know you're probably bouncing around projects and other things so might be hard to keep track which part you're on :)

[@valentine_puppy]

I loved this series very much. Thank you. 😀

[@another3997]

The delay in opening the jpeg isn't because of the image compression, it's primarily the reduction to 256 colours. That is really processor intensive.

[@flowerpt]

Grounding through the RF shield? That's one of the craziest things I've seen them do. Back in those days Apple literally had an A team and a B team for hardware. I suspect the A team was busy working on Quadras or something when the Color Classic was imagined and handed to the B team. This was Performa-level shenanigans.

[@chrisbalfour466]

Some DLP projectors also use the shielding as an electrical connector on the power board. A loose screw would keep it from powering up. Specifically all the Viewsonic PJD models.

[@bob0507]

Thanks for this Color Classic repair series, it was really fun to watch!

[@shadowtheimpure]

I've made that torte recipe, it's actually REALLY good. I highly recommend it.

[@katho8472]

So quickly?

[@ToTheGAMES]

@@katho8472 As if the site appeared at the same time as this video... LOL

[@katho8472]

@@ToTheGAMES Haha of course it existed longer but I supposed that "shadow" got aware of it through this video, as did I, being just a German noob :P

[@shadowtheimpure]

@@katho8472 Nah, I found that site years ago crawling the web with Netscape navigator back in the early 00s.

[@JosephBloggs5233]

Using the RFI shield as the audio ground would probably have been done to help stop radiated emissions from a cable plugged into the audio jack. If the audio ground were connected to digital ground, any noise on the digital ground would be able to radiate from the ground conductor of the cable plugged into the audio jack.

[@tekvax01]

(13:49) It is quite common to have two separate grounds, an analogue ground and a digital ground. Typically these grounds would be joined together at a single common point (ie. Star Ground) in this case the RF shielding. I have repaired many switch mode power supplies that have an isolated ground, and yes, you must connect them together when the supply is on the bench, under test, or it will not work.

[@RcAircraft]

Well done in finding why the sound would not work and sound advice for anyone else having the same problem. 👍

[@zinnythecat1726]

I fully enjoyed your fault finding solution in the sound. So funny finding out the shielding was the problem. In the future removing the shielding may be the problem why things don't work . Lesson learned. Great watching look forward to future videos.

[@piratk]

I think Dave on Eevblog discusses the split planes approache in one of his latest pcb review videos.

[@TheSulross]

Adrian's channel is what convinced me to just enjoy retro computers vicariously - I bought one (Tandy Model 200) and it works, but it will be the one and only. Otherwise will stick with modern neo-retro computer recreations, FPGA MiSTer, and the like.

[@kokodin5895]

well on most motherboards from pc's , at leasy pentium 2-4 era audio was also insolated grom digital ground they had only connections made by single 0 ohm resistor and had it's own power rail filtration caps all that was made to stop digital noise interference to analog aution which would produce high pitch noise hiss , but also audio interfering with bass sounds pulling ground up and making digital errors on the other side i belive in this case shield worked as low resistance resistor link that would stop crosstalk along with rf interference interesting bug non the less

[@nickwallette6201]

Just FYI - when you were looking at the scope trace of the audio signal, it was jumping up and down when you plugged in the external speakers. I have a theory on what caused that. Audio circuits are AC coupled, at least usually. It’s always nice when you have +/- voltage rails so the AC can be centered around 0V, but quite often it’s using a 5V DC supply. This means you have to center the AC waveform around some DC bias voltage to make sure the negative swing of the signal can go below the reference point. You would then use a capacitor to remove the DC bias and re-center the waveform around 0V. Hence, AC coupled. (Even if you have a -5V rail, you still need to AC couple to make sure you don’t have a ground potential difference. Moreover, in many cases the -5V rail is only used for amplification and the D/A is still DC biased. I haven’t looked at the Mac schematics though.) The “outside” or jack side leg of that cap needs to have a ground reference, since there’s no DC flow through the cap. Usually, the input stage of whatever you’re plugging into (like a powered speaker or a mixer, etc.) will have a resistor to ground. This sets the input impedance to something between 1K and 100K, often around 10-47K. Instrument and mic level inputs are higher (maybe 1M), balanced pro audio is 600R, but you get the idea. That R to ground pulls the AC coupled signal to ground, but isn’t strong enough to short the output, so you get a voltage swing around Gnd. So what you may have been seeing on the scope when you plugged in the audio cable is the external ground being applied to the AC coupled waveform, bringing the bias point down. Particularly if the ground reference was missing on the internal speaker circuit path.

[@molivil]

I sold a MAC SE/30 for a lowly low price because I could not get the sound working except from the headphone jack! I tried everything, including replacing the capacitors, checking all connections, resoldering in case of cold joints... to no avail. Finally I have the possible answer to the mystery.

[@6581punk]

Frodo was never a particularly fast C64 emulator, mainly due to the portability of the code and accuracy of the emulation.

[@chrisbalfour466]

I had a 7200 LS with a Crescendo G3 upgrade card, but still couldn't get an SNES game to run without choppy audio. I switched to PC after I saw someone with a cheap 486 running an SNES emulator flawlessly. DOS was just less of a bottleneck for gaming than Mac OS.

[@leonkiriliuk]

NEC did the same thing with the original white PC Engine. The RF shield on the bottom used to connect ground to the exp port.

[@Ikrananka]

Another example of a split ground relying on an RF shield for connectivity is the cartridge port on a ColecoVision game console. Pin 13 of the cartridge port replies on a mechanical connection to the lower RF shield to be electrically connected to the central ground.

[@mephustowest1876]

Awesome series and I loved it. Our first computer was a black and white mac around 1991

[@hernancoronel]

Conclusion: RF shields may be useful! LOL! Love your content Adrian, thank you for the videos!

[@AmbientMusicStudio]

"Just for a quick recap.." Funny :D

[@adriansdigitalbasement]

Very punny :-)

[@mikesilva3868]

@@adriansdigitalbasement 🤯

[@johnmcl7]

I was amazed at the quality of the picture which wasn't what I was expecting at all, I thought it would look much more basic. We had some of these Macs in the school lab although I don't know exactly which model but definitely didn't have much ram and had the black and white screens which I think is why I was so impressed to see such a detailed image as I just think of the basic mono graphics the ones I used had,

[@Natures_Intentions]

That is one awesome vintage MAC. Awesome job with all of the repairs as well!! The video looks awesome on my late 2009 macbook!

[@Technichian462]

Called it at the first mention of audio not working through speaker, but does work in headphone jack. Bad connection in the internal jack. There is a mechanical 'switch' that turns off the speakers when you insert a headphone jack. Most common issue with that kind of hardware. Troubleshooting 101: Follow Olcums Razor.

[@BCProgramming]

One reason it might be so slow is that JPEG uses quite a bit of trigonometry and it might be that the FCOS instruction isn't available with that CPU (I think it was added to the base CPU with the 68040) which would mean the math has to be handled via software emulation.

[@IvoryTowerCollections]

Coleco did the same thing on one of the cartridge pins where the bottom RF shield provides the ground to the pin. If you don't have the bottom RF shield installed, the system and games still work but there is at least one home brew game release that uses that ground on the pin in order to operate properly. So there is at least one other system that did something similar.

[@amostake]

I could have been troubleshooting that for 50 years of my life and never figured out that wonky ground setup.

[@UVOS-z4q]

Good job man! Stop throwing out rf shields! :P

[@sedrickgates1]

About jpegs, I recall in the mid 90s that at the agency I was a student, we had a JPEG Card to speedup creating the files. We had quadra machines and a megapixel Kodak scanner :-)

[@chloedevereaux1801]

i reckon everytime adrian say's IT FREAKING WORKS he has a secret 8bit dance party in his head :D

[@twocvbloke]

Them RF shields, they finally had their revenge... :P

[@bf0189]

Mind blown! The RF shield was actually useful....what are the chances?!?!

[@tekvax01]

(06:02) The audio is AC the 1 volt DC is the bias voltage... The 1-volt bias is NOT an A/C signal, it is very clearly DC.

[@muttBunch]

Nice Adrian. I’m addicted to every one of your videos. I need to get an oscilloscope and learn how to read them from a signal standpoint.

[@craftsman123456]

This would be a good one to revisit for the 640 res mod.

[@qwaqwa1960]

Split ground planes (rarely a good idea) still tend to be joined *somewhere* on the board.

[@marksmith9566]

There was probably rf pickup on the ground plane on the motherboard. The sheild creates a faraday cage to box in the RF. That's why the external connectors are attached to the sheid ground.

[@pheffr]

I wouldn't be surprised if Apple split the ground plane just to make things harder to troubleshoot. In a previous episode, I think you mentioned that (even back then) Apple wasn't handing out schematics to their techs. Splitting that ground plane obviously made it infuriating to find the sound problem in your Mac.

[@darkstatehk]

I freakin' love this channel. Period.

[@marc6340]

I have a color classic that has NEVER booted up. After seeing you working with one, I took it off the shelf (mostly to see what motherboard it had, no Mystic board in there!) and I discovered it had NO RAM onboard. I need to find my "Box-o-Ram" and see if I have anything compatible in there. I'll let you know what I find out!

[@SidebandSamurai]

Great video. If you are looking for a game that will run on the classic mac color, There is one I had called "Happy Weed" Its a pac man type game were you run around eating marijuana leaves, cops are the ghosts that chase you and you smoke a doobie to freeze the cops so you can put them in jail. I realize that you might not be in to this type of game but It is funny to play. You run around the maze and collect doobies and can use them when ever you want. The game was well programed and has over 1000 levels. Anyway for the later macs it might not play very well as it does not check for CPU speed and plays way too fast even on the slowest speeds.

[@Gany1701]

I liked this series! Great to see it working now imo

[@scottaw1981]

wow, finally an RF shield put to good use.

[@Tomlinsky]

My Analog Ground/Digital Ground radar was blipping as soon as you were jostling the plug in the socket. Weird SCSI hooked into 'Analog' ground.

[@sittingstill3578]

Hoping to see _Escape Velocity_ show up in the games review. Ambrosia Software was my favorite studio in the 90s and early 2000s. They had a little RPG too.

[@nevyn]

"This was the last mac in this form factor" -- well, except for the Color Classic II (aka Performa 275), yeah? 😅 thanks for this video series! So much nostalgia, really fun to see the internals and some classic software. We had a Color Classic when I was growing up for maybe 6 years or so, and even though it was so slow me and my brother played _so_ many games on it... Had an external harddrive and CD player and everything, gravis joystick, etc. I remember playing Doom on it being... not fun at all 😅 you had to play in a literally post stamp sized window for it to have a tolerable framerate! (Our next machine was a 5200, so if you have any like that one around I'd LOVE to see it ;D also I have a LOT of mac retro hardware from that era if there's every some more weird parts you need...)

[@alerey4363]

To improve apps on older apple hardware running os 7/8/9 try assigning plenty of ram per-application (select executable icon, get info, memory, typically u double the minimum recommended size); if you really have a plenty of RAM installed in the logic board you can create a ram-disk, reboot, copy the slow app into ram disk, assign it plenty memory and try again; great detective job on the ground plane issue!

[@wolvenar]

I can suspect that this was made this way to isolate and give a preferred path for static discharges. It might not be a big deal, or it might. I think I would have at least recreated the connection path keeping that grounding from the digital areas separate as possible.

[@jaycee1980]

There's a couple of reasons to have split ground planes, as you correctly say RF emissions is one of them. However in this case, it is probably that Apple have an analogue ground plane for audio circuitry, which is connected back to main ground at one point. This is often called star grounding, and the reason is noise. Ground planes carry return current, and digital ground will carry a lot of noise from all the high speed switching going on. You want to keep that out of your analogue ground returns otherwise the noise couples across and you hear it in the audio output. It seems a bit silly of Apple to rely on the RF shield for this return path though. It could be there is supposed to be another path (eg sometimes analogue and digital ground planes are isolated by a small resistor) and that path has gone open circuit. The change in DC level you were seeing on the audio is probably because the audio is capacitor coupled (AC coupled) and, because the analogue ground was missing, these capacitors were not charging (as there is no ground path for them to do so). You are thus seeing the DC offset that the capacitors would normally remove.

[@john_ace]

I did the VGA mod on one of my Mystic CC today. It was very easy and works perfectly. Sadly the Comm-slot and LC-PDS cannot be used simultaneously. I had to connect an AppleTalk to Ethernet adapter to get the CC on the net while having the Apple //e card installed.

[@Controllerhead]

Hmm. I wonder if the second ground was to isolate the noise signal from "digital blipiness" coming through the speaker? Just a thought. Great content as always!

[@shieladixon]

thank you for saying gif before jif! It's wonderful to see that machine doing its stuff. Someone is keeping a list of http websites which work well in older browsers. But I didn't manage to keep a bookmark to that list. Maybe someone knows or can find it.

[@i.t.manager513]

Hi Adrian, long time viewer, I especially enjoy your troubleshooting and repair videos. In part #3 you 3D printed a new rear panel for your custom Color Classic. What brand is the 3D printer and would you recommend it ?

[@dummptyhummpty]

My Color Classic has the same sound issues as yours. Even the audio chip gets hot. Sad that your fix didn’t work for the original logic board.

[@Waccoon]

The difference in speed must be extraordinary, because the original Mac had a painfully slow bus arbitration scheme, so it couldn't use the 68000 CPU at full speed anyway. Based on my experience with Amigas, a 68040 on a 32-bit bus is about 3 times faster than a 68020 at the same clock speed. A 25 MHz 040 with fast RAM can be expected to give 12-15x the performance of the stock 7MHz 68000 you'd find in an A500. The 040 was a beast and a huge leap forward for the 68K architecture in its day (and insanely expensive).

[@rfmerrill]

It's almost like RF shields are something the product is designed to have and you can't expect it to work perfectly if you remove it ;) I'm guessing they just took a shortcut to avoid having to have an extra ground net or an extra pin on a connector. Grounding through structure is something you see all the time in cars, so it's not unheard of but usually uncommon in electronics. Usually you want to avoid passing a significant current through the RF shield, but I suppose with analog audio, the frequency that's expected to pass through it is so low it wasn't a concern. Also, the audio is probably capacitively coupled, and since the ground of the audio jack needs to be connected to shield ground anyhow (as it's a cable that extends out from the device, so digital ground could turn it into an antenna), they decided that was all it needs to be connected to. I don't know, I'm not an EMC or RF expert.

[@travishein]

I see this separate "analog ground" and "digital ground" thing in some of my audio interfaces. it makes sense, to help prevent any digital noise from leaking out to (possibly sensitive to noise things) audio things, like an audio amplifier. But it is super weird how the analog ground here was relying on the RF shielding material to complete that circuit. I guess Apple should have used a separate wire and connector would have been better right.

[@johnyoder9302]

Where does the Macitosh classic II fall in the two computers in your video?

[@robertbruce7686]

Good job. I think I now have more respect for the Mac family!

[@pb7379-j2k]

You can tell Adrian isn’t a true Mac user because he keeps talking about drivers! Forget drivers, Adrian, it just works!

[@JFinnerud]

Google search still works using http instead of https. We tested it a few weeks back using Netscape on a SGI o2.

[@MrChrisRP]

It was a yelling at the screen moment for me. hahaha

[@arf20]

Ahhhh you can load google.com in HTTP! You should have tried that

[@CollinBaillie]

I wonder if simply installing a scsi terminator on the back would be a suitable solution? Especially for those who don't want to solder the ground planes together. Or just have the RF shield installed I guess.

[@cyphi474]

Routing ground trough that RF shield was pretty bad idea.

[@BryceTheBicycleEater]

Wow, that brings back memories. Even though I knew the answer of the shield grounding, I had completely forgotten about it. Yes, I was a Mac technician back before the Genius Bar killed most of the independent Apple Authorized shops off. P.S. They aren't board-level comprehensive, but if you want I still have a copy of the Apple Tech Disc, it goes all the way up to 2005 so it not only covers all models of Mac, but also iPods and Newtons as well. Somewhere in my collection I also have the older Tech Disc that has the Apple // files. Let me know.

[@GalileoAV]

Idk why but the milk.com thing was hilarious, it's so wonderfully old school

[@danfuzz]

I aim to please! ❤️

[@mrcassioo]

@@danfuzz Love it! ❤️

[@DishNetworkDealerNEO]

Was there separate left and right audio channels or are these computers monaural?

[@malanvogt]

It finally got you.

[@video99couk]

Nice EEVBlog 121GW Multimeter. I've been trying to buy one but they are unobtanium now.

[@andlabs]

Ah I was hoping this would happen someday, but with an Atari 8-bit machine - I wasn't expecting it to happen with a Mac! Of course thinking about that now, I wonder whether the Atari 8-bits - or the 800XL specifically - actually do need their RF shields (according to Retro Recipes anyway) and why. Of course the other fix would have been to restore the RF shield, but since the one from this machine was rust-damaged and actually seemed to have pieces from the sound port section broken off it if I'm watching part 1 correctly...

[@helldog3105]

Hey, strange question. Is anyone else getting a strange almost harmonic distortion on the sound when Adrian speaks? I haven't noticed it before in the videos I've watched. It sounds almost like distortion or interference? Anyone have any ideas? Now that I've heard it, I can't unhear it.

[@mikeuk666]

keep up the great work Adrian 🕹

[@MisterAML]

They use the shield to ground two parts, nice find. Difficult anyway

[@suluturnip]

The RF Shield Strikes Back

[@donmoore7785]

Very nice job on the 3D printed panel. It's amazing what can be done with 3D printing. Assuming that you can discard RF shields and retain functionality is um, foolish.

[@LxRv]

Sweet, now you can play Twisted and a Whole Mess o' Trouble!

[@Zeem4]

Nice work! I wonder if current versions of Linux still support AppleShare. Several years ago I had Netatalk running on my Linux machine, I could browse my server from a Mac Plus using a Powerbook 5300 running LocalTalk Bridge, it also worked from the Basilisk II emulator. I once went as far as taking a Powerbook 520 into work and using it for real work (circa 2010), because we had a NAS on the network that spoke AppleTalk, so I could work on suitably-formatted Office documents and save PDFs to the network share.