0080 A 128k RAM upgrade for the Speccy, some recovered SIDs, USB-C Cable testing and a new DMM
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- Опубліковано 5 бер 2024
- On our next super mini mail call we have a few goodies for the Commodore 64, the ZX spectrum and a few things that are essential tools for testing stuff.
-- Video Links
USB Type-C cable tester:
caberqu.com/home/20-c2c-caber...
121GW multimeter from EEVBlog:
eevblog.store/products/121gw-...
ZX Spectrum 48k RAM expansion:
github.com/goloskokovic/zx16t...
Spectrum RAM diagnostics:
retroleum.co.uk/diagrom/
blog.retroleum.co.uk/electron...
github.com/brendanalford/zx-d...
Adrian's Digital Basement Merch store:
my-store-c82bd2-2.creator-spr...
Support the channel on Patreon:
/ adriansdigitalbasement
Adrian's Digital Basement (Main Channel)
/ @adriansdigitalbasement
-- Tools
Deoxit D5:
amzn.to/2VvOKy1
store.caig.com/s.nl/it.A/id.16...
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.com/products/digi...
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.com/item/33000...
TS100 Soldering Iron:
amzn.to/2K36dJ5
www.ebay.com/itm/TS100-65W-MI...
EEVBlog 121GW Multimeter:
www.eevblog.com/product/121gw/
DSLogic Basic Logic Analyzer:
amzn.to/2RDSDQw
www.ebay.com/itm/USB-Logic-DS...
Magnetic Screw Holder:
amzn.to/3b8LOhG
www.harborfreight.com/4-inch-...
Universal ZIP sockets: (clones, used on my ZIF-64 test machine)
www.ebay.com/itm/14-16-18-20-...
RetroTink 2X Upconverter: (to hook up something like a C64 to HDMI)
www.retrotink.com/
Plato (Clone) Side Cutters: (order five)
www.ebay.com/itm/1-2-5-10PCS-...
Heat Sinks:
www.aliexpress.com/item/32537...
Little squeezy bottles: (available elsewhere too)
amzn.to/3b8LOOI
--- Links
My GitHub repository:
github.com/misterblack1?tab=r...
Commodore Computer Club / Vancouver, WA - Portland, OR - PDX Commodore Users Group
www.commodorecomputerclub.com/
--- Instructional videos
My video on damage-free chip removal:
• How to remove chips wi...
--- Music
Intro music and other tracks by:
Nathan Divino
@itsnathandivino - Наука та технологія
Another vote for a speccy video or two, or three …
Peter from caberQU here,
thank you for the in depth review of the C2C caberQU! It is a pleasure to develop these things and even better to see people liking them.
What about USB-C to USB3.x A cables? Thanks
@@tomn5660 That's a good question, we have the A2C caberQU for this exact problem, which can test USB-A to USB-C cables.
Just got my caberQU a few days ago (despite USPS's efforts). Works great. I've been deep diving into PD as a result of this.
@@ChrisDreher That's great to hear, thanks for the feedback
I've got one too, very handy!
Thanks Adrian, glad you got it. No point spending time trying to troubleshoot the old one, it's likely a tolerance issue on the range switch contacts, pressure and thickness of the PCB on those first batch units.
Adrian's little sid-dances always make me smile. :)
Me too! Adrian's such a likeable, funny fella.
Would definitely like a speccycentric episode sometime... I designed and built my own FPGA-based "super Spectrum" ZX Prism... 512K, 256 colours, different resolutions, built-in DivMMC and virtual tape etc. One day I hope to make it an open source project that others can built but for now, there's only one and it's over here in Australia!
The ZX Spectrum plus was a keyboard "ahem" upgrade only....Loading tapes on any early british 8 bit was always a joy/challenge. The spectrum compared to the oric was a dream to load tapes...
it also has a reset button which was actually a huge improvement over having to pull the power.... which is literally a button with mod wires soldered directly to the reset pin.
@@ThePoxun Just noticed the reset button, you can hardly see it ! Also the plastic legs to give the ideal typing angle........
ZX Specrum was my very first computer (I was about 10 I think)! LOVED it!!
Just ordered C2C Cable tester. I have been entirely perplexed by all the different cables and also the fact I can find none in my possession which transfer more than USB 2
Anything with a physical rotary switch will wear. Good application of contact cleaner will help generally. This is where Fluke shines - the switches last a really long time and work even in high humidity reliably for many years. I have one that was actually submerged in a flood, after disassembly, drying, contact cleaning and reassembly it's worked fine for nearly 20 years. VERY expensive however. Deoxit will work ok, surprisingly wd-40 will help in a pinch. I usually used tuner cleaner when I had charge of repair/calibration for the physics department decades ago. Cleaning contacts will not disturb calibration as long as you don't get it in the pots (normally on the accessible side of the board)
yeah, I was just saying this. I had to take apart my good expensive MM and clean the wheel with Deoxit once, but it's been fine for many years since I did that. I'm sure it's a humidity thing
In working with rotary dial switches, whether it be Fluke, Simpson, or Triplett, the switch oxidation can occur, simply from use in moist environments, & general 'wear & tear'. Motorola use to sell a contact enhancer call Stabilant which works well.
@@oliverw.douglas285 Probably quite similar to fader lubes?
Funny enough, i had three flukes that were stored together in a cabinet and 2 of the 3 died. The only one that didnt was the ammeter type which was the cheapest one. The only one i had left was one that i kept in a humid garage. I am assuming the ones in the cabinet died because i had some massive N52 magnets stored on the shelf above and me pulling the multimeters out induced some random currents in the meters killing them.
@@jeffreypomeroy6173 I don't expect strong magnets would be good for DMM. Fluke's are typically resilient to RF Fields.
I'd be really interested to know if the 128k RAM expansion would turn your 48k into a 128k as the ROM was very different, really interesting to see a follow up using it and making the mod - also troubleshooting your bad tape loading as I'm sure you could fix that. As others have said, more ZX content always welcome 😊
Hi Adrian, Nice goodies. and thankx for sharing with us. Greetings from Steven from the Netherlands
It's real Serbia Special today. ZX Renew resells products from RetroRadionics who did the ZX Omni, ArcadeR joysticks, replacement keyboard membranes, metal plates and even reproduction ZX Spectrum 48k cases amongst other things. RetroRadionics operates from China and is run by Djordje Mitic. Djordje is from Serbia :)
Reminds me on finally buying a decent multimeter.... The one I have I got for Christmas when I was like 6 or 7 and it was already cheap by then.... so now it's almost 40 yeaers old, but still works!
Hey Adrian, you will be surprised on that uni t clamp meter. You say it's the range button and i thought so as well the first time in mine. But i was wrong. The battery compartment is like a clam shell. The battery compartment has spring contacts to the pcb. Grab the case and twist/flex it. It will flake out.
What i ended up doing is soldering the battery contacts to the pcb with wires.
I had Issue 3B board in 1985. I had colour always a bit "off". Spectrum tape checks: check oxidation in 3.5mm socket. Don't connect both of them, if you load programs connect just aux. Tape recorder/ player MUST be set to mono. It also must never put to max volume. Border stripes must move "lively". If everything fails, use screwdriver to adjust the tape head. Else hardware.
The Spectrum Plus is still only a 48K machine. The first 128K version had a large metal 'toast rack' heat sink on the right hand side. The ROMs will also be different as the 128 had two separate modes (48K and 128K) and a small built in menu.
yup the zx spectrum+ 128 has a 128K legend on the right hand side.
I'm still using my METEX multimeter I purchased in 1992 - first one - still working without any issues.
Still using my Fluke 77 from 1984 but also use a few others.
The ZX Spectrum plus is just a regular 48k Spectrum in a new case, Sinclair even sold kits to upgrade the rubber keyed machine.
i know, i bought the upgrade keyboard direct from them, still got it 😉 £20 for the keyboard to do it yourself, £30 if you send it to sinclair for them to do it for you
the CaberQU seems to be a really cool tool! Thank you
Thank you Adrian! I was having a positively foul day until I got the notification for a new video! ❤ Keep up your hard work, we love your videos!
Might have been said before in the chat, but I love how Adrian actually says "Zed X Spectrum" and not "Zee X Spectrum". Just feels so much more authentic. I think I only discovered Zee because of sesame street as a kid
The range switch issues &tapping on the switches on the multimeters makes me think of this joke;
"Man goes to the doctor, says 'It hurts when I do this!', so the doctor says 'So stop doing it then!'" :P
Greetings from Serbia...
Got my caberQU C2C at about the same time as Adrian. Loving mine.
Sinclair produced a kit to upgrade any regular ZX Spectrum to a Spectrum Plus. Other than a new case and keyboard the only other addition was a reset switch, which connected to either side of a parituclar capacitor on the main board.
cool I didnt know Dave designed that meter awesome
Nice new ring!
I'm so happy that both of the SID chips i send you are working. They have been i a drawer in my basement for somewhere between 15 and 20 years. No they will come to life :-)
It must feel awesome. Good on you sending those to Adrian.
I have the same ANENG, used to give random resistance reading in continuity mode. It turned out to be the rotary switch acting up. Just clean up the gel and dirt on fingers on the PCB, do not reapply any gel or lubrication, it will get dirty again. The EEVBlog multimeter might have the same issue, it's worth cleaning that one too.
Useful tip: Tie an overhand know with both leads of the multimeter near the pins that go into the multimeter. This keeps the leads together so they won't get lost and go astray. This has been quite useful to me with the variety of meters I've used.
For measuring low resistances i have an old (but surprisingly accurate (lab tested)) bench-multimeter (30 kg) from the sovjet-era. Its a bit slow in auto-ranging, but finding shorts does work pretty well. It can measure mOhms and other very low values.
I have been to Denmark in the 1980's and found the Danish people there are very nice!. I really enjoyed my visit there. I was there for a month. And enjoyed my time there. I love the food there too! and I ate breakfast with their butter milk. At first I did not want to drink it, but once I did and after a month, I was hooked on Butter Milk. Its not bad at all Adrian, please keep the videos coming. I have not seen any new videos yet. Looking forward to one soon.
There's a reason we Southerners love our buttermilk biscuits. 🙂
I'm looking forward to the Spectrum edition of the show
Cable tester looks really useful
I found one more useful where are 9 connectors - "Treedix USB Cable Tester" treedix.com/cdn/shop/files/51A4YdF4nGL_540x.jpg
For the 128K ram, you can use the 128k rom (not +3 rom, it looks for the disk controller on startup and will hang if not found) with the advanced basic interpreter. That won't work without the 128k ram since it does a bit of a ram page swapping diagnostic on startup, but does not need the AY chip unless you try to use extra sound commands beyond beep. I know this because I wrote a z80 emulator and extended it to a ZX spectrum emulator. The 128k ROM wouldn't initialize until it successfully swapped through all the pages.
The problem is, the rom switching is done via the same output ports (and by extension the same logic) as the ram switching. So, unless that expansion supports putting multiple pages (2 roms for 128k) of rom on that flash chip, I don't know how you'd use it properly. I would expect it must allow you to load roms onto it somehow.
I have to take my aneng multimeter apart periodically because of the same issue. I clean up the switch with IPA and put a bit of silicone oil onto the PCB. Works perfectly after that, very consistent, but it doesn't last more than a year.
Great video as always. The Spectrum Omni Laptop looks great, seen a couple of videos on it. With batteries in it makes a great portable Speccie.
The 121GW is a great meter. I highly recommend to get some Probemaster probes/leads to use with it (or use with any other multimeter).
I still have my first multimeter, one that my uncle gave me when I was a LabKitten helping him work on old cars back in the early '80s. It's an analog sweeper and it's maybe only accurate to a tenth of an Ohm or Volt, but it still works!
My work multimeter is a Fluke 179, which is a beautiful piece of kit and has lasted me over 15 years of almost daily use. It has a great backlit screen, a responsive processor, and handles nearly every task I throw at it. But... it's pricey.
I can also recommend Klein Tools' MM300. It is also a nice budget meter and is excellent for LabCatting, but the stock probes are junk.
also just FYI, I've had continuity issues with several Multimeters, including my very nice expensive one; all it took was taking it apart and treating the main selector wheel with Deoxit to fix it, and it hasn't given me any trouble for years now
I have an ancient hp4357a that's great for tracing shorts. even in modern motherboards and gpu's with big complicated vrm's you can usually trace the short down to individual component with 7.5 digits. even tho it's kinda beat up and slow and a hasn't had a proper cal in decades it can make very precise comparative measurements across a circuit.
I also bought a multimeter from Dave. It's a BM786 and has 4 decimals of precision and is slightly longer (taller).
CCx lines will light up on shield connection on e-marked cables. Those have an active IC inside with parasitic paths to the CC lines.
For that cable tester, it _can_ actually tell you a little bit about the current rating of the cable indirectly. All USB C cables are rated for 3A or 5A, and 5A cables (among other cable types) _must_ have an e-marker chip.
If you have a cable with an e-marker chip hooked up, one CC LED will glow at full brightness and the other CC LED will glow dimly. This means that if you do _not_ see this pattern, the cable _must_ be a 3A cable with no e-marker chip.
Put another way, 3A USB2.0 cables don't require the chip, but cables that are either 5A or USB3 *do* require the chip. It's not a full answer though, because you can have e-marker cables that are only 3A if they're high-speed USB3+ cables; to tell those apart you need a tester that can talk to the e-marker chip, but in my experience most 5A cables are marked as such and so you mostly just need to confirm that a cable is _not_ 5A capable if it's unmarked.
Regards from Serbia
Need to do a session on fixing multimeters.
That specy seems very intesting
The spectrum plus is exactly the same as the regular speccy. It has better keyboard and a reset button, nothing else.
The woodwinds in that sample track sound almost like an AdLib instrument on the 8580. That's really interesting and I wonder what other FM synth style sounds were possible using similar techniques.
With that USB-C cable tester, the CC1/CC2 lights will light dimly if there is a chip inside of the cable and you only touch the ground on the other side. Also there is a very similar device that does USB(A-2, A-3, C) on one side and (Lightning, microB, miniB-2, miniB-3, fullsize B2/3, and C) on the other.
i know the joystick ports on the original spectrum were on the cartridge add on as far as i know. i remember having the original sinclair 1000 but never used it and then it eventually got thrown out. i miss it already. there are lots of computers i want to end up with but finding one isnt cheap sadly.
Shield should be connected at only one end. If it's connected at both ends it's a ground loop.
Nope, that's only in analog audio. All other shields must be connected at both sides, just like with a single core coax.
@@WhiteBream No, not quite. Ground loops are not an "audio" problem. They're a signal problem. They affect every signal, whether you can hear it or not.
Some cables use ground as the signal return, so you can't do anything about it. (Coax.) Other things, including some audio cables (XLR / or mono differential on TRS) don't use the ground as a signal return, so you can lift ground on one end without a problem.
All that said, ground loops only exist when there is a difference in ground potential that is big enough to have a significant influence on the signal's interpretation. So the best cure is for that not to happen to begin with. When devices are floating (battery powered or double insulated), then it's not an issue. When devices use a safety ground, that ground should not be carrying current, and both devices should have low impedance paths to the same common point. Then, the shield of an interconnect isn't acting as an equalizer between two different reference points.
@@WhiteBream I humbly disagree, The exception is when the shield is the only ground(and a common ground is necessary). This is normally the case with analog audio and RF coax.
The issue is that if the shield forms a loop with a superfluous ground conductor external noise signals are inductively coupled to the signal conductors.
The truth were hoping for is that all ground pins(not signal negatives) are connected to shield at both ends with no other ground conductors. I can't think of a simple way to test for that off the top of my head.
@@brocktechnology When a shield gets interrupted (for example by not connecting a connector shield), everything beyond the interruption forms a dipole antenna against the outside of the shield of the cable. So quite the opposite effect of the intention of the shield. Search for "Unveiling the Secrets of Return Currents: Theory and Practical Demos" for more info
Holy moly! ….that multimeter is $225 in Amazon. I have the same one normally shown on the Retro Hack Shack channel….a red cheap Innova 3320…but works just fine. I think I paid like $20 bucks almost 9 years ago for it.
The Innova 3320 is a 2000-count CAT II multimeter, while the 121GW is 50000-count and CAT III. ACV precision: 1mV vs 1μV. DCV precision: 0.1mV vs 1μV. Current precision: 10μA vs 1nA. Resistance precision: 100mΩ vs 1mΩ. Also, the 121GW can measure capacitance and frequency, neither of which can be done with the Innova. That said, the Innova has a battery testing mode that the 121GW doesn't have.
None of this makes the Innova bad, but it is generally less capable. If you don't need those extra capabilities, great; you saved yourself $150. But some people do.
(Count has to do with display precision. 2000-count means that it will measure a thing with 4 digits of precision until the first digit gets to 2, and then it jumps to the next range. So for example, you could measure a resistor at 1.999Ω, but if it was over that, you'd be measuring it at 02.01Ω. Or 19.99kΩ, but 02.01kΩ. Whereas 50000 means you might be reading the same resistors at 1.9991Ω, 2.0009Ω, 19.991kΩ, and 20.099kΩ, and you'd lose that 5th digit of precision once the first digit reaches 5.)
(And CAT II vs III has to do with safety ratings. I'm not terribly knowledgeable here, but it usually has a lot to do with physical build quality.)
@@wbfaulk thank you for the in depth description of the excellent capabilities of the professional multimeter shown on the video.
I certainly don’t need all the bells and whistles for the amateur work-hobby that I do. Obviously, they not comparable, as I said the innova is a $20 dollar multimeter that works for me…I was just surprised to see the price tag on the other one, but I guess is worth it for an electronics technician.
add a usb-c voltage amp meter in line
spray some deox-it in the multimeter selector knob. they get dusty and the lock washer on the backside often gets loose.
I use non rechargeable lithium AA cells in my meters, since they last forever and do not leak (or they have not leaked for me yet). On 9v low draw stuff I use "heavy duty" batteries, which tend not to leak. Also on one of the cheap meters, I would try Deoxit D5 on the contacts. If they have carbon traces, you need to use the Deoxit F5 Fader lube. I killed a bunch of potentiometers with D5 before I figured out that you have to use the F5 Fader cleaner on carbon traced stuff. Good luck.
Those 121GWs look like great meters, however, long as my Fluke keeps going I will keep it going. I do love it and have abused it and still super accurate.
Great stuff Adrian, I love the multimeter especially ... Now I understand that you can "make" a multimeter with a RPIs or similar with a clever little harness with safety diodes.
If you've any advice or could even do a video about that, it'd be *fantastic*!🤓
The Ikea battery thing is real now, my Dad works at a UK store and said that they only do rechargable ones now in the UK, so I daresay its international now (of course it is, UK and Sweden!).
It's for sustainability reasons, for some reason!
Hope that helps.
Are your Ladda's, 18650's?
Most Spectrum games I remember that were 128k, would typically have 3 voice audio as the "extra bits" for the higher RAM model as they'd typically want to keep 48k compatibility without having multiple versions.
I was about to say the same thing. The main reason to have a 128 back in the day was the sound chip, not the memory.
It would be interesting to see how compatible an expanded 48K Speccy is with 128K software, though. I can imagine some issues it might run into, but I don't know how common they are in the real world.
@@duncansnowden6857I'm curious about this too. How did the 128k Speccy know to load in the extra goodies back in the day?
@@kyorin6526 As far as I recall, most programs weren't smart enough to adapt. You'd either have two different versions, with the 128K one simply crashing on 48K machines, or, if the only difference was AY sound, it would just “play” silently on a 48K machine. Waggling the I/O ports that control the chip on 128K machines doesn't do any harm on a 48.
I'm sure there *are* ways to check and adapt intelligently, but I'm not the guy to ask.
@@duncansnowden6857 I'm sure I had a game called Chronos back in the day that somehow loaded extra stuff on the 128, it was probably just the sound/music that was different though.
@@kyorin6526 It was a setting you selected at startup whether to be in 128k or 48k mode at boot up on 128k machines. Or at least on the later Amstrad ones.
if you had a 80s portable tape player (like brochures of the day suggest) i could set the volume for you so the spectrum always loaded, it was a skill back then.
My best advice is set the volume wheel to 7 to start with if you have such a player
It's possible that Eurostile keyboard came from a C64 as Commodore used whatever they had at the time, but most likely from the Vic, as they had the PET keyboard, then the Eurostile, then finally the narrow style we see on later vic's and C64's.
The Eurostile keyboards are my favourite to use also.
I have 2 Fluke 172’s that are indestructible. Never had an issue except when the batteries get low.
Hi Adrian. I believe the official Apple (USB-C) cables have a chip in them, and a single CR2034 battery might not power it up enough to show all the modes it’s capable of. It probably needs at least 3.3 volts, but that’s just a guess, whereas the cheapo cables probably have just some termination resistors in them so a CR2034 is probably good enough. That being said, I haven’t cut into any Apple-branded USB-C cables to see the chip… Mostly because I need mine intact, and I’m not packed with cash to splurge on a spare just to cut open! 😆
I hate you because you have my dream job! hahaha, Mainly a Commodore guy but love all your videos and even enjoyed the MAC re-capping one. Keep them coming! Greetings from Ukraine!
I believe the AR on the 6581AR means that it's the pirate version ;)
the cable tester is cool
Check the batteries of the meters. Continuity/resistance mode relies on good batteries. With a bad battery voltage and current can still fine.
Just open the multimeters and use deoxit on the range switches, they are bound to oxidize eventually with use or with out.
My multimeter is a Tenma 72-10415, I chose this model after a good bit of research and am quite happy with it. It was a great price-to-features ratio and designed well. But that was several years ago, and it looks like this particular model is no longer manufactured. Perhaps their newer models are still a good choice, I don't know.
The EEVBlog 121GW (1.21 gigawatts…nice) is currently US$215. The Aneng meter is $26. For a basically 10x price difference, I don’t think it’s fair to expect even remotely comparable quality and precision.
Test equipment that doesn’t work 100% of the time can be annoying, but it can also be deadly. If you’re working on equipment that is high enough voltage to shock you, having equipment that doesn’t reliably show correctly can lead to accidental live work (which is exactly why there are requirements for live-dead-live testing methods).
Golden Fluke 😍
Adrian, just spin the dial on your meters rapidly a bunch of times. Like 20-100 times. Usually cleans off the contacts.
If that doesn't work, then dismantle them, and clean the contacts on the switch fongers and PCB traces used for the dial switch.
I've resurrected multiple multi meters this way over the years when they started doing that
Normally, Adrian would be the first to exclaim Deoxit! He seemed reluctant for some reason, yet is happy to spray it all over an "irreplaceable" 40-year-old computer. 😅
Please adjust the contrast on the new DMM. Also, you can use Lithium primary AA and AAA batteries, they only have a slightly higher voltage. But never seen those leak.
Still have and use my "wallet" multimeter from Tandy/Radio Shack. Over 30 years old and still working fine.
I have a question (and please don't interpret this as a request for shorter mail call videos): what exactly does "super mini" mean in terms of these videos? They don't seem so mini to me, which is fine since I enjoy longer videos :)
I think the original idea was to make mail calls about a single item rather than cover 5 or 6, like in the mini mail call.
It's also running joke as to how he tries to make short videos but ends up making them way longer
They started out mini, but quickly grew to maxi, and it's been the joke ever since. If you go back and watch the first few, they are actually fairly short.
Ive found issues with the selection switch on a couple of my old multimeters. Ive tried cleaning contacts, but hasn't really helped much...
you can make a short program with poke and peek commands to interrogate the memory.
It would be an interesting project to mod the USB3 Cable Tester with a microcontroller and a two-line display to show which type of cable is connected.
Dude! When in doubt, De-Oxit. As I understand it, De-Oxit has several formulations, so you might be better off with CRC QD Cleaner.
That Spectrum RAM upgrade cries out for a 3D-printed case. Ivan (pr: EE-vahn) mentions you can manually select 128k but the software defaults to 48k...
Switch oxidation and/or dirt in "ball" switch in multimeter. It is repairable, did it on my "field" multimeter years ago. I agree that it is annoying. Also check/clean/tighten probe ports if you decide to mess with it (they are visibly less shiny inside then of the new one).
BTW, I used "Kontakt 60" spray for cleaning- It is some kind of clean, de-oxy and it has lubrication capabilities (surface remains slightly oily after spraying). Great (and expensive) stuff, it is German, I don't know US equivalent..
13:15 My AN8008 has recently started behaving the same...
FYI "International Karate" has some of the best music :)
USB-C cables designed for charging - like those Apple includes with laptops - tend to have thicker conductors for lower resistance at higher wattage applications. I've found that any cable I purchase that includes the words "charging" or mentions wattage are always USB 2 cables. The consortium should have enforced a marking system to help eliminate this confusion.
1:22 I thought you 2 of those testers, till you turned the page 🙂
those multimeters likely just need the switch contacts cleaning, , i've had to do a few...
No difference between the Spectrum + and the rubber key except the keyboard. My first spectrum was a plus, so I've got a bit of a nostalgic "thing" for the keyboard. It had an issue 3B board.. Loaded everything just fine (and I didn't ever have any problem with any other issue board particularly - though that was in the 80s). You've tried all the things I'd have suggested to get loading working consistently - amp etc. Only thing you didn't mention which I'm sure you tried - make sure you're plugging into EAR on the spectrum, make sure the socket's tight and make sure you're using a mono jack at the spectrum end, and sum the LEFT and RIGHT output from the modern device rather than just use one or the other (not usually an issue, but can help under some circumstances)
That cable tester is great for determining which pins are in use but if you want to truly know everything about a cable you need a tester that can read the E-marker chip. Plus those tell you exactly what kind of cable you have without going through that nightmare of a chart.
Just need to clean the dial pads and contacts for the meter. That's one of the easiest multi-testers to upkeep.
We’re all missing Mr Lurch! No output for 5 months.😢
A USB-C cable tester. Yep because it's such a good thing that we've finally established consistent and stable standards...
About battery leakage - unlike 3V lithium manganese dioxide cells which can leak, I have never had a 1.5V AA lithium-iron cell leak, even after many years. This includes Energizer and Chinese brands. I think it has more to do with the chemistry than the manufacturer. I much prefer Li-iron to NiMh as rechargeables have a very flat voltage curve & thus they go from ok to fully discharged without warning.
Is the basement super humid? That can make the copper contact tarnish faster. Maybe you need a dehumidifier.
26:30 in my experience, those industrial ones are worse. Energizer max supposedly have a no leak guarantee.
Would have been really nice if that USB tester had connections for all the different USB headers so you could test any type of cable.
6:00 A lot of the USB-C power cables only do USB 2.0 (and are advertised as such).
Im wondering if Deoxit may help your range switch issue? *edit, you mentioned it. I'd try, what do you have to lose?
Deoxit on the contacts would be better than not doing that.
Yes please a big episode on the Spectrum stuff, mix it up a little instead of always PC, Mac, C64. Perhaps a live stream speccy repair marathon and a look at that Speccy with the acreen.?
Why not bring some of the stuff you've been hoarding in the basement sent in years ago out and prioritise them to make some videos about these other things? Place them in your video rotation, otherwise you'll probably never get to them and people have been good enough to send stuff in yet it sits languishing for a long time.
I think some greater variety would be a good thing.
Was wondering if have c64 from 86 had gotten when I was in school couple months ago I lost sound do you think it's the sound chip
Put DeoxIT in the socket! 😎
Two resistors on the usb tell it how mutch power you can take. 🙂
that ZX Omni would be even cooler if you could put rechargeable AA's inside it, and use the power brick to charge them