This Commodore PET has 3096.01066 bytes free! That can't be right.

#commoore #rgb2hdmi #repair #diagnostics
It's time for a Commodore PET repair. This machine has an impossible amount off free RAM and some unusual problems. Let's try to figure out what's wrong so I can figure out how to find the exact problem with this machine.
Part 1: This part!
Part 2: • Let's troubleshoot and...
--- Video Links
RGB2HDMI profiles for the 40 col PET with CRTC: (these will be included in the RGB2HDMI release)
github.com/misterblack1/rgb2h...
Romulator RAM/ROM FPGA based Replacement: (VIC-20 video)
• Replace your 6502 comp...
Commodore PET 2001 Series:
Part 1: • The Commodore PET Rescue
Part 2: www.youtube.com/watch?v=3Jyuk...
Part 3: www.youtube.com/watch?v=Y4BTf...
Part 4: • PET Rescue Part 4 - It...
Zimmer's archive of PET schematics:
www.zimmers.net/anonftp/pub/cb...
Commodore PET Diagnostic clip on ROM:
www.6502.org/users/andre/petin...
RGB2HDMI Github repo:
github.com/IanSB/RGBtoHDMI
Buy RGB2HDMI:
texelec.com/product/rgbtohdmi... (includes the Raspberry Pi Zero)
retrohackshack.com/product/rg...
Adrian's Digital Basement ][ (Second Channel)
/ @adriansdigitalbasement2
Support the channel on Patreon:
/ 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

[@ovalteen4404]

That extra fraction of a byte shows Commodore's dedication.

[@colinkraus7139]

I like this comment

[@kargaroc386]

that 1/12th of a bit

[@DavidKimFX]

This channel is amazing! How do you not have 5-million subscribers already?? Because you SHOULD!!

[@oldguy9051]

Adrian's subscribers count is like a number of cat years compared to human years: It's worth about seven times as much!

[@DaleDix]

@@oldguy9051 Channels take years to grow a channel to that size - unless they're playing minecraft and a gazillion children subscribe or they're doing something controversial or extraordinary. Even though it may be due, there isn't enough people that used to mumble "38,911 basic bytes free" in their sleep when they were young.

[@mariusberger3297]

I always love seeing a PET getting repaired. I've managed to amass 3 different models (2001, 2001-N and 8032) and am currently restoring my flood-damaged 8032

[@josha254]

F in chat for it.

[@josha254]

It's possible that a Mini-PET could be used as a replacement mainboard. I've watched the 8-Bit Guy and I remember he used a Mini-PET board as a replacement

[@ActionRetro]

Wow, what an ewaste save!

[@THEmuteKi]

My wife wanted me to let you know we're glad you've given this machine a new home. When it comes to Pets, adopt don't shop!

[@TheSudsy]

It always reminds me of Computer Studies (1981-3) - the PET was sat right in the middle of the classroom, connected to an accoustic coupler. No one ever sat at it unless there really was no other computer available. BBC B, BBC A, Spectrum (latterly) , ZX81 then the Pet.

[@donmoore7785]

That diagnostic feature of the design is pretty darned cool, and I love how you were able to emulate it the way that you did.

[@HutchCA]

The NOROM signal is also used by the Super PET to disable the ROMs for the 6502, when the 6809 CPU takes over.

[@quinntechretro4927]

I want to commend you on another excellent job explaining complicated technical things. I took some rudimentary electronics courses back in 2003-04. I love how you try to explain the problem in semi-layman terms. I get a lot of what you are talking about but am a little lost at other times, at no fault of your own. I also want to commend you on your "presentation skills." I see you seem to be more comfortable and fluid in front of the camera. Kudos!!

[@Fredthefat]

Thanks Adrian, love these fault-finding and repair videos, really appreciate your logical and honest narrations. I learn something from each one.

[@EgonOlsen71]

What these Commodores do to print out this value is to take the integer value of the bytes free, convert it into a float value stored in the floating point accumulator (some bytes in the zeropage) and then convert that value into a string to print it out. In this case, I would rule out the ram, because the routine basically works, it just gives wrong results. The same applies to the ROM. That leaves the CPU. It can have a minor fault where it doesn't update the carry- or the zeroflag correctly in some cases, which could lead to such results.

[@MattKasdorf]

I was thinking the same, plus it's an easy thing to swap out to test.

[@kaitlyn__L]

I was wondering where a floating point value would creep into an integer memory count, thanks for explaining that signal chain :D

[@albinklein7680]

Amazing, that you can still find PETs in the e-waste bin. Nice find and it ended up in the right hands!

[@LeftoverBeefcake]

Yes, I'm kicking myself for not thinking of checking our local e-waste companies, there's no telling what retro goodies have passed by. I'd be so stoked if I could find a PET without having to resort to eBay. :(

[@a_Fax_Machine]

It's my dream to own a PET some day. It is daunting though knowing how many issues they typically have though. So I'm glad for videos about how to fix them. Great video as always!

[@MyChannel-vm6dw]

I can't tell you the amount of joy I have watching your videos. The respect and care you have for this tech that literally helped shape many of our childhoods is greatly appreciated.

[@watsonac79]

This video sorts me out on the ROM situation for the universal motherboard so much! Can hardly wait for the next video. I am presently in the middle of empirical action on the RAM - new sockets and chips for all. I was fine and got started then one day. 98 bytes free…. Trying get to fiddling around with a Z80 & C/pm daughter board I had hanging out in the lid, an Easter egg when I found my 8032…

[@WesleyNixon]

I just saw your 3d printed solder spool holder. I printed and use the exact same holder on a regular basis. Nice.

[@CDP-1802]

I 3D printed the same one but it's kinda lightweight and the center spindle on mine kept popping out, I ended up trashing it and buying a Hakko 611 holder which is rock solid.

[@adriansdigitalbasement]

Heh yeah I've had that little thing a couple years now and it's very handy!

[@truezulu]

Well prepared, nice tempo, very interesting and nicely explained. Thanks Adrian. Such a joy to watch.

[@Inadvisablescience]

The first computer I ever saw was a Commodore PET. I cannot thank you enough for these videos which will come in handy when I get my own classic computers. There's nothing like the real thing. Glad this channel exists.

[@MatthiasWelwarsky]

The PET was also my first computer to play with. I remember fondly turning it on and then typing in the question: "who bent the banana?" to which I got the iconic "SYNTAX ERROR" resposnse. What can I say. I had never been close to a computer before.

[@kaitlyn__L]

@@MatthiasWelwarsky I have a similar, but later, memory of the DOS prompt in Windows 98 - I typed versions of “die windows”, “kill windows” etc and thought the BAD COMMAND response was a promising sign that it was fighting back. I amused myself for a few days like that.

[@darkstatehk]

I love the repair vids so much, looking forward to Part 2!

[@milk-it]

Really in-depth diagnosis, Adrian. Good work!

[@SellamAbraham]

Hi Adrian. I appreciate all the general troubleshooting hints you provide in this video.

[@DavidWonn]

100.01066% quality video as always!

[@RetroGamingWithBigSteve]

I occasionally see these go up for sale in the portland area on craigslist. Still hoping to snag one some day. Always fun to see a PET restoration. Great video!

[@frankowalker4662]

Interesting. Can't wait for the next part.

[@TheClassicsCoder]

Your video's are really awesome and in each one of them I have learned something new, no matter how well I know the system. You rock!

[@twocvbloke]

makes you wonder who thinks "Hmm, this old computer can't be worth anything so I'll just bin it!!" without checking the internet first, but, at least you have it now and is on its' way back to health... :D

[@Charleshawn66]

Another GREAT video as always!!! TY!!!

[@Vermilicious]

Impressive diagnostics!

[@ralgha]

Very impressive screen capture prowess and chip select trickery. In awe, as always.

[@wwsoft]

Very interesting set of issues and diagnostics!

[@Innochamp]

Love it when someone takes care on these old computers👍🏻

[@TheEmbeddedHobbyist]

Remember the pet has floating point maths, don't think it does integer maths.

[@HutchCA]

Nice trick to jumper CS from the Kernal to one of the option ROM socket. I need to remember that one. The Romulator can replace the kernal but not everyone has one of those.

[@adriansdigitalbasement]

The biggest issue is programming a 2532. But a simple PCB or hand made adapter is all that's needed to use a 2732 instead.

[@VintageTechFan]

"Piggybacking" it on the Kernal should also have worked (but less reliable)?

[@AlejandroRodolfoMendez]

Good luck with the fixing of this machine. Nice that you recycled before it was too late. I love the pet chasis, never had or seen one irl. I'll like a similar desing but for a modern pc

[@Dr_Mario2007]

I love seeing the ancient computers revived and fixed as it means a lot when it comes to preserving the last remaining functional piece of history.

[@chrisshaw4723]

Another great video, thanks

[@Michael500ca]

I love retro computer videos and I am so glad this one is less than thirty minutes in length. The simple reason for that is I don't have time for videos more than thirty minutes and in my experiences most people don't. Please keep these videos to this magic length.

[@Michael500ca]

This is the first time I have been able watch a video on the channel for months since the others were too long.

[@8bitwiz_]

Don't forget that you can save a little time by watching videos at 1.25x or 1.5x speed. But I also don't like watching videos more than thirty minutes long. He found a good stopping point for this one.

[@ianstorey1521]

What an ingenious way to use the diagnostic chip!

[@m4rgin4l]

I just love how this case opens.

[@haruruben]

this was my first computer I ever used!!!! so much nostalgia, I remember the first time I saw it- it looked like something from the future

[@AceStrife]

I'm still amazed by hardware working 40 years later. Anything made today seems to just fail in just a few years, or in barely a year if it's a peripheral. Maybe not a complete failure, but degrades in one way or another which affects usage of the product. God forbid you buy something that's a refurb/recert.. those go so quickly. Every time I turn on my computer I worry some part of it will suddenly be dead, especially a storage drive.

[@albinklein7680]

Funny, that budget electronics from this era last longer than professional stuff or even mil spec field equipment of the same era, because of the lack of exploding tantalum capacitors...

[@Psychlist1972]

If you approach one of our e-waste bins at the drop-off here, and don't have something to deposit, they yell at you. I saw some cool Commodore stuff in ours once but they told me to get away.

[@jasonc3a]

"[this video's] gettin kinda long" Only time I can recall hearing that on a video from this channel less than forty minutes lol. The disconnect between minutes of unedited footage versus an edited together video combined with how every person perceives the passage of time differently always makes statements like that throw me down a rabbit hole.

[@AmstradExin]

I just dreamed of sitting in a Tram, seeing Adrian and through a store window, repairing an old car. I smiled and waved and he smiled and waved back.

[@sylwo_28_37]

Hello Adrian. I am an automation engineer, i love to entertain watching Your movies. Your "deduction" path is similiar to mine. Your accent, pronousing is vsry very "understandable". Keep going good work!

[@glonch]

I'm an Apple guy, but your explanation about the Commodores (PET, 64, etc) is very interesting. Well done!

[@maxxdahl6062]

@Brandon Taylor Definitely better for gaming anyway. The graphics and audio hardware were absolutely amazing for 1982.

[@maxxdahl6062]

@Brandon Taylor Yeah the IIe is definitely better for productivity. my aunt and uncle were Apple IIe people then went to the mac. We had C64 here in my house and then we went to IBM PC's.

[@primus711]

Explain how its better for productivity than a c64 ill wait

[@maxxdahl6062]

@@primus711 mostly because the Apple could display more columns on screen etc. I'm a commodore guy but apple and IBM were always better for productivity.

[@primus711]

@@maxxdahl6062 that's all debatable and c64 could do 80columns in software

[@jeffreyphipps1507]

Yay! Another multipart old computer repair project like the Model II. I love a good miniseries!

[@ProlificInvention]

This is my favorite computer of all time, as a 2nd grader I was the only kid who could program and load games on them, I also got cassette tapes from the regular library and played the games at school. We had 20 or so of them in our computer lab in the early 1980s, my mom was the media center lady so I had free reign on them and it was my thing to be the "computer genius" and geek. I remember some of them had like calculator keys, and some had commodore style thick keys. All had cassette tape drives for data and games of which we had a decent selection of. I also remember we had a few Apple 2Es which were great as we had tons of software, as well as being the first school in the country to get the Apple macintosh in a pilot program. They replaced all our PET computers with them, and I still remember all those computers sitting in a back hallway for a long time and asking repeatedly if I could take one home but was always told no. I actually contemplated just taking one, I can still remember 😆 Those games really were next level on the macintoshes because they had actual graphics, lots of games, even though they were just black/white/greyscale which I thought was stupid.

[@tarkhan15]

always nice to get a bonus bit

[@RobTheSquire]

Nice to know that some places do auction off old hardware..If I had the space to have an old pc or two I would have jumped at the chance to grab any and max them out and just simply enjoy them.

[@retrogamingandyou2373]

My dad was the principal of a small town K-12 school. The school had Commodore PETs like this before I attended school but the summer before I started Kindergarten they all got replaced with Zenith IBM PC clones. They knew this was coming by June so they went grade by grade asking the students if they wanted a free PET. It took... I think going down to grade 10 but every PET found a home.

[@rottmanthan]

i have a ibm 5150 that was owned by the university of Maine and i live in Maine, so i thought that was cool.

[@jamesavery3559]

very nice thank you.

[@edgardovigo147]

Very interesting!

[@d.jensen5153]

4116 DRAMs seem so primitive until I remind myself of core memory and the discrete transistor drivers that were the interface to it. :o

[@MisterMsk]

I wonder if you could use Bondo's fiberglass resin on the case to go over the engraving and other scratches? Then possibly rattle can the entire case and print a new sticker for the front.

[@notneb82]

I've done this before on a TRS 80 that had really deep scratches and a piece of the case broken off. It looks fabulous if you know your way around prep and paint.

[@adriansdigitalbasement]

There is a very distinct texture to the case plastic, so I think it would be really hard to replicate although maybe not for someone with a lot of skill?

[@notneb82]

@@adriansdigitalbasement There is a simple little trick for plastics with texture. Get a hot glue gun and place a blob of hot glue on the textured surface and place a stick in the glue standing up. Once cooled, carefully peel up the glue with the stick still in it and viola, you have a texture stamp that can be used while the filler is soft.

[@DrTofu83]

@@notneb82 Yup. Hot glue or also polyester resin and anything that hardens but stays kinda flexible and can be torn/peeled away without bonding with the texture you're matching. Then you can press it on the filler or even the paint, if you go with painting with several thick coats

[@a_Fax_Machine]

@@adriansdigitalbasement you'd have to take a mold of the texture in silicone, and then use that to re-add the texture to any epoxy resin you use to fix the damage. David Murray has a pretty good video from a few years ago about doing that to fix the lid on a Bell & Howell Apple II+.

[@adventureridergirl]

So I just started this video and both of my daughters (1 year old and 2 years old) came running over when they heard your intro music, lol. I think they were expecting an 8-bit dance party.

[@PhilR0gers]

I remember when the Personal Electronic Transactor (PET) was first announced and would have loved to have one. At school I was using different computers (Research machine 380Z), which had some proper graphics capability, so when I finally got to use a PET, I was quite disappointed. But it's still an iconic machine.

[@paincreatesfame]

Well we've always been pretty good at recycling in Portland so I'm not shocked that so many school district PETs are still around. We'll always find a way to make old things be useful here!

[@anders4u222]

I learned to program on one of those... and wrote a program for the local ski center to manage their ski rentals. Had to load it from C-cassette at startup😄

[@Jo_Wick]

0:54 this would be a really great out-of-context snippet right here

[@micheldurieux6430]

Another treasure saved. Adrian to PET: Never gonna give you up, never gonna let you down :)

[@plan7a]

I noticed that Rick Rolling in the background also, LOL.

[@SentaiBrad]

I'm sure its not the first time you've mentioned you're in the Portland area, but TIL I learned you're local! I'm down in the Salem area, and learning a bit about what is going or on, or has happened in the area is interesting. I always see LGR, RMC and GamersNexus talk about cool stuff near them but they're not local. xD

[@MSmith-Photography]

I kinda wish that I would've offered to take one of my high school's Commodore PETs when they were getting rid of them in the early 90s.

[@NivagSwerdna]

I was shouting at the screen saying just swap the editor rom with PETTEST but the diagnostic ROM info and NoROM line is actually pretty interesting!

[@thomasoeffling304]

Kids and grown-ups love it so - the happy world of Haribo!

[@HutchCA]

I need one of those RGB2HDMI. Definitely a useful device

[@richardbanks2669]

If you can solder, you can build your own - everything you need is listed clearly in the wiki attached to the project. It's all on GitHub, hoglet67 RGBtoHDMI

[@HutchCA]

@@richardbanks2669 I at least need a PCB.

[@richardbanks2669]

@@HutchCA The files are all there to order a PCB from one of the cheap internet suppliers - PCB Way, JLCPCB, Oshpark etc - depending on how long you're willing to wait for it to arrive, and what import duties/taxes your government levies, it can cost less than $10. If you don't feel confident ordering a PCB ( and honestly, it's a lot easier than you'd imagine, very user friendly these days) there are people on various forums ( try stardot the BBC micro forum) who make 'group buys' where one forum member will buy PCBs and components in bulk and then ship them individually to anyone who wants a kit, at or near cost price. There are sometimes people also selling kits on eBay, and Tindie, although you never know when they might have stock. Good luck :)

[@mikeuk666]

More Adrian goodness

[@Foxonian]

The computer I learned BASIC on in high school back in the early 80's.

[@kargaroc386]

Just going off of the looks of the machine, I think I can see why a lot of these might've been saved. It has that retro-futuristic look to it that people like. In the 80s when these became obsolete, they could still do useful work, especially with a modem. BBSes probably worked just fine on these. But as their usefulness dropped off, their beauty picked up.

[@SteveMorton]

The PET was the first computer I ever saw!! The one with the original keyboard and the built in cassette 'drive' Yes this was in the mid 1970's! Nearly 50 years ago!

[@d455ave]

Back when they were new, I used to repair the older versions of PETs, apple 2 plus, S-100 computers, and the earliest IBM PCs. Chip level repairs, aligning floppy drives, all that stuff.

[@Quickened1]

Those are genius steps!

[@Vallee152]

I got rickrolled by the CRT in the background XD

[@svenpetersen1965]

Interesting topic. Doesn‘t the /NOROM signal go to the option ROM sockets, too? That stack thing is weird. Somehow, a stack must be living somewhere else. Because, when you boot up, several subroutines and also the interrupt service routine is called. And that would not work without a proper return address from the stack. Exciting video, looking forward to the next part.

[@RudysRetroIntel]

Excellent video and work. My friend is working on the same motherboard but has a double churp. I have the fw8b diagnostics chip that replaces the cpu. Have you seen it? Thanks again

[@EirkenElite]

Best looking pc of all time

[@nickblackburn1903]

What's an E way stream Adrian? Destined for recycling? Lovely videos thank you

[@0623kaboom]

Commodore Pet 2001 and 4032 are what Space invaders was orignally hacked with ... by 6 guys in high school in Canada ... Ottawa to be exact ... . was great fun using the daisy chain network to drive the teacher nuts too when trying to get a program to work for her next class lol . mind all 6 of us had to have our class work done first and each prgram handed in .. of course we had to do the same assignemtn 6 different ways so we wouldnt be called on cheating ...

[@Pedro8k]

A later version I remember seeing them with the tape drive and chiclet keyboard way back then at schools in the UK before the BBC micro then replaced them

[@cjhickspe1399]

That video bit was awesome. I have a working PET so I've never had to dig into that. Could use some help on the 8050 dual FDD drive though...

[@ginkumpow3726]

swap out the PIA and see what happens, they're flaky

[@cjhickspe1399]

@@ginkumpow3726 I think it's on the analog side actually. I have two - one with mechanical damage - and the plan was get one working but C= used different revs. I haven't dug into it all the way yet. This video did inspire me to power up the 4032 though and it was satisfying to see that still works.

[@fred_derf]

This was the first computer I had access to, I remember how disappointed I was when I opened it and nothing was happening. I don't know what I was expecting but the system was so magical it was a major letdown to see that it was just a thing.

[@thewhitefalcon8539]

then you studied electrical engineering and it was magical again?

[@fred_derf]

@@thewhitefalcon8539 The systems are still magical, I just stopped expecting the "working parts" to be interesting to watch work.

[@rager1969]

Heh heh, in one of my math classes, we had one PET and two Apple II computers. There wasn't a whole lot of time to use computers but what little time we had, no one ever used the PET.

[@timblake5844]

NNNOOOOOO! Oh the suspense! Don't leave us hanging!

[@rolandkatsuragi]

7:40 I was unaware that the PET could function as a space heater.

[@dhpbear2]

Wow! Was it standard practice for 'Commode Door' to *solder* in ROM chips?

[@IanSlothieRolfe]

It depended on the model, age, place of manufacture or phase of the moon! My early 2001-N I've had from new has socketed ROM chips, a 3032 I have is also socketed (although that was acquired second hand, so may have been modified), but I have seen many pictures of CBM mainboards with soldered in ROMS, particularly later models. I've heard that Commodore had supply issues with a number of components and would sometimes solder in sockets for chips they couldn't get then put the chips in later, rather than hold up the assembly line, but it does seem that as time went on soldering in ROM chips became increasingly standard practice, I remember at the time that there were many reports of chips coming out of sockets when power/heat cycled many times.

[@whoisme678]

Those were the days when computers used keys to wind them up 🤫😆. I remember assembling a sinclair zx80. Lol...it didn't work cause I dropped a component and couldn't find it...for a while when I did it finally came to life and how disappointed I was . They said." Flicker free graphics "...lol there wasn't any.😆😆😆😆😆😆

[@CanuckGod]

Interesting to hear a (former) Canadian talking about CRTC a lot in a video that has nothing to do with the CRTC 🤣Obviously they have the same initials to the controller chip, but a totally different beast... (For context, the CRTC - Canadian Radio-television and Telecommunications Commission - is our equivalent to the USA's FCC or Federal Communications Commission) P.S. Also don't mean to imply that Adrian isn't Canadian any more, just that he has resided in the US for quite a while now.

[@microcorelabs7698]

My MCL65+ could also be dropped-in to replace the 6502 which can emulate all of the PET's RAM and ROM. Perhaps not as user-friendly as the ROMulator, but does allow the user to enjoy some acceleration modes such removing 6502 cycle-accuracy and mirroring the RAM/ROM at very high speeds. Could make you machine the World's Fastest PET. :)

[@adriansdigitalbasement]

Videos coming soon now this PET is on the bench :-)

[@hicknopunk]

Sounds cool!

[@kittyztigerz]

it would be nice to see some upgrades on that pet pc

[@rpavlik1]

Fancy! Not sure how many of these you do, but seems like that diagnostic stuff seems like a useful candidate for a PCB that plugs into the socket instead, so you don't have to bend chip legs. But, then you'd have to find chip leg shaped pins to solder into the PCB instead, maybe that's harder than replacing an EPROM after wearing out the bent-out pins.

[@SellamAbraham]

"Stay healthy, stay safe" is the equivalent of telling people to wipe after they poop.

[@Okurka.]

The perfect poop doesn't need a wipe.

[@UpLateGeek]

Sometimes I wish computers these days were this easy to understand and troubleshoot. It seems like half the work on this was just getting the lid off!

[@jasonbalicki7948]

Oh, hey. I have one of those portland PETs. Bought it on ebay years ago.

[@8bittimes]

IIRC the userport on the PET has the video signals. You could connect your video converter there

[@RoamingAdhocrat]

got more RAM than my PC! which has no RAM

[@8bitwiz_]

The first thing I thought of was bad RAM. All it takes is a flipped bit to mess up a number like that, and those 6502 BASICs all use single-precision floating point everywhere except when they need to be converted to or from a 16-bit integer. Other things were weird enough that I also expected it might be a whole column bad or something like that. The error that came up implies that there is aliasing between the zero page and the stack page, which would be quite troublesome on the 6502. It's quite right to stop the test right there, because having the stack crash into and twiddle with the zero page can cause some really subtle problems. At least try re-seating all the DRAM chips first, and check for tarnish on the pins. Sockets are nice for repairability, until oxidation makes a pin or two stop working after a decade or two. As for the display, I'm guessing that the CRTC was initialized incorrectly. Probably it is "scrolled" to the third line of the screen, and the first two lines are simply hidden. I wouldn't be surprised if that's being caused somehow by zero-page vs stack interference during the initialization. Fix the RAM and you'll probably fix the screen.

[@ejonesss]

youtube allows up to 24 hours in length and 12 gig in file size a couple years ago memes like 24 hours of music and windows starup stretched to 24 hours was a thing. so that is a green light for you to upload longer videos

[@mondocommodore]

Very good!! A question, I have many commodore PET/CBM, and some have problem with chip ram. I have see this chip are with 200ms, other 250ms and other 150ms (on different machine) time access. Can I replace all the bad Memory chip ram with 200/250ms time access with chip at 150ms? Sorry for my english

[@tommylee2k]

holy moly, you have an open Haribo-Happy Cola rail exposed on your desktop. that's extremely dangerous! :'D nitpicking just to be a nit picker: 23:40 it's 65536 addresses that can be addressed, 0 - 65535 :P