Building a Commodore 64 Diagnostic Test Harness

hello everyone welcome back to Adrienne's digital basement for today's video we're gonna be working on the Commodore 64 diagnostic test harness that Sven sent me all the way from Germany I showed off the PCBs he sent me in mail call number one the first of such videos I've made so if you haven't watched that click the link in the description below or in the box whichever corner it is to see that video as a side note I'm shooting this on my brand-new Panasonic Lumix g9 camera think called the G 95 in other international regions and I'm also shooting with some new lights for my basement so hopefully this sounds and looks better than it was with my old camera and of course hopefully and I don't know yet because I haven't used this camera much no more crashing let's get right to it [Music] so before we take a look at putting together this kit let's take a look at why I want to put this kit together on the bench you see my good old handy zip 64 and I have the easy flash 3 cartridge and on here I have actually flashed one of the diagnostic roms that is commonly used for the 64 let's just take a look at that yeah let's pop this in 64 there you go hooked up to the good old 1084 here and I have down under tools I found this collection online of just a bunch of useful tools for the 64 but c64 diag cart B I'm pretty sure that this is the one that's gonna work with it diagnostic rev five eight six two two zero and taking a look at spins board Diagnostics rev five eight six two two zero so it matches what's on the computer right now when the diagnostic runs through you here it's doing the BP beep CID test but notice here we have a whole bunch of things that say bad cassette control serial port user poor interrupts and these three ICS all marked bad and the reason for this is the commodore 64 has no way to actually test its io lines unless you use the user port which is what this is and you run cables to things like the cassette port which is this little PCB or the joystick controller ports which are these two connectors which run with cables to this or you have a loopback connected to the keyboard which will test that or recreate a loopback connection inside the IEC port this is the connector that would go into the serial port on the back of this that's where you hook up your disc drives so let's talk about building this thing i've laid out everything on the bench which i think i'm gonna need to build this thing all the information you need to build this is on Sven's github i'll put a link in the description to that so don't forget to check that out there he has the files for the pc b--'s themselves so you can get them made but also the instruction manual plus the building materials or BOM for everything we'll need to put this together and if you don't have an easy flash 3 cartridge like this you will need a diagnostic cartridge to plug into your Commodore 64 spends github has a PCB to make one which here it is right there versa kart 64 but since I already have the diagnostic on this easy flash I don't actually need to put this one together so we'll skip this one oh we almost forgot I'm gonna need a couple hundred nano farad bypass capacitors for the user port port so ignoring the PCBs themselves I've obtained everything you see here off of Aliexpress of course that means being patient and waiting for that stuff to come this is why I'm putting this kit together now even though Sven sent me these PCBs months and months ago when I received these PCBs they were actually bare and I've already installed these two chip sockets along with the user port connect but rest assured I did by this user port connector and the matching cassette port one off of Aliexpress on Sven's github you'll see a picture of the entire kit assembled which kind of gives you an idea of how it should look once it's done and he has another picture which I'll show here actually running the diagnostic that I just showed running on my own Commodore 64 and everything showing okay with nothing bad while he has the harness connected what's even cooler and I won't be doing that for my kicks I don't really care that much is he does provide STL files so you can 3d print cases for all of these parts which means they'll look extra professional and real as opposed to just bare PCBs which is how I tend to keep things alright time to warm up the soldering iron and get started assembling this stuff okay I'm gonna try some dual camera action here using my old crappy camera and the new camera together so I'm gonna start with the cassette PCB because I want to show you guys how I connected the user port connector it's exactly the same methodology you used to do this and these connectors are a little bit different than say a standard pin type connector here taking a close-up look with the pins I'm not exactly sure what these originally connected to or how these work but if you take a PCB it does fit and line up in between the contacts but there's a lot of space there so we're gonna have to do some bending of the pins to make this work so I did this on the user port board and all of the pins are soldered on and connected well and it makes the whole thing quite stable so when you plug this in and out of the back of the computer you know it works and doesn't just flop around now unlike the originals which had a little slot cut inside the connector these aren't keyed in a specific way so we just need to solder them on any which way and then when you plug them into that computing to make sure that the the traces and the components face-up move this out of the way because my method of dealing with these is just to bend them and they're quite springy so when you bend them you got to go quite a bit past and then they'll spring back hopefully you can see that's why when we look at these they're a lot closer together so to get the PCB and it's almost to the point where I actually have to kind of bend these down a little bit with the edge of the PCB a little fiddly but don't worry this happens to us there we go so now this is actually kind of holding us how on you can see this can go either way I'm gonna try to solder this on where it's at a 90-degree angle so I usually try to find something to kind of prop up the PCB and I see one piece one part of my scissor there that pretty much does the trick then we have to make sure that this is totally aligned like that so it's correctly straight on every which way and we'll dab a little bit of solder on the tip here heat up the pad then just flood the solder on that I'm just gonna do one to start with so it's not totally straights a little downward slanting so I'm gonna melt that and I'm going to reposition it just so it's straight let's solder all of these pins on all right so this is looking really good no issues with that you all right that's one cassette port board assembled okay let's move on to this little board here for the keyboard port he does say right here no pin so I actually did snip this and I didn't solder it and I guess theoretically I should shove something in there that way you don't accidentally put this on backwards now all this needs to be done on this is there's an LED and there's a resistor the resistor that's needed is a 330 ohm we just double check this one yeah 330 so I'll snip this off I'm going to put this on the back of the board here you can put it on either side whichever works better for you but because I'm using the connector there I'm gonna gonna put this this way and then this LED there we go like that let me just double check and see to make sure the LED negative is going to the rewards the resistor okay I'm glad I checked that's actually backwards on the this cassette port adapter the negative on the LED is actually going towards the resistor but on this one the negative is going towards the ground which is one of the pins on here so I'm gonna go and I'm just gonna bend the legs with a resistor over and let's just get this connected okay it looks good let's just snip these legs off always keep your little offcuts from these parts because these are perfect as jumpers if you remember on my PCB that I made for the Tandy I kind of screwed up and I needed to jumper the 245 out and if I want to do that permanently you could just use these little legs to you know go from pin to pin and I think there is a zero ohm resistor that's been calls for coming up and I will be using one of these little off cuts all right so these two are done now I'll put these away and let's pull over the user port board so like I mentioned already I have already soldered on the user port connector the blue connector here I put these two IC sockets nothing really special about that I have some of the pin header connectors here that will be going on so there's this one there there is this one here and then there is one more right there so checking the bomb we have one zero ohm resistor I'm gonna use this metal off cut here are three there is 320 ohm resistor well all I have is a 330 ohm and he says on the PDF that 330 should work so stick that in there now next we have some other resistors I'm gonna need to use my multimeter to see what these are this one here is 150 ohms and that is in the position and r4 just right next to that 330 ohm I think this makes a voltage divider to allow something to do with the cassette port drive signal to be used as a logic signal so I'm just gonna solder these two on here because I'm gonna have to do something a little bit sketchy for the other four resistors that are going on this board ar7 next to the two resistors I've already put on that's the zero ohm bridge I'm just gonna stick that on right now okay so therefore more resistors to the left are 5 6 & 2 & 1 these need to be 120 K and I just don't have anything in that that revalue I have 100 K and 20 K and what I'm going to do I'm going to cut the leads off and I'm just going to solder these together and make a little pyramid so to speak it's going to be kind of ugly and sketchy but it will do the trick and it will work okay so all 400 on those are the four probably the hundred K or the 20k I'm not sure but I kept these separate just so I wouldn't mix them up so these are the other two or other four rather just cut off the little tape we're gonna do the opposite we're gonna thread these in the other side I mean this is so sketchy I paid attention to the building material so that I would have known I had to order some 120 k resistors it's not a value I've ever needed before there we have these two resistors up against each other I'll just have to put these leads together and we will solder those on well I'm definitely not proud of what I did here with these resistors but this does get the job done maybe this is incentive to print that 3d case do you hide the ugliness that I have done here let me just break in there bringing the multimeter here and we'll just double-check that these are indeed 120 K now 119 120 dot 0 0 well that's quite accurate one nineteen point nine one one nineteen point nine zero people check this one 119 okay so everything is about 119 point 9 or 120 so looking quite good so the rest of this is self-explanatory we got the connectors and you see there's even a notch in the soap screen which matches the notch on here so that's perfect very easy you just line this up and push it on all right those are all connected up so what's left on here we have three capacitors and actually there are three test points that's been put on here I think test point is 5 volts there's a ground one and another 5 volt one over here I won't put those on for now I don't think I need those alright I think the camera cut off and when I was soldering on the capacitors now the camera did not crash it just has a file size limit for our video recording which my new camera doesn't have so we can record indefinitely until the card fills up so now what's left is to install these two ICS these are 40 60 sixes yes I got these from China so I think they work do I know if he's work I can't remember if I was able to test these I don't know if my IC tester does that does the mini pro test these I don't remember it was well install the eath hopefully they work just bend the pins or bent them a little bit there so there we are I think the user port is done and then the cassette port that should be done and the keyboard connector thingy inside the computer that is done what I need to do is open up this connector to put two jumpers in here and then we have the cables to make well it's time to make the cable and that weird noise you're hearing is actually my water eater which is just sitting to my left the gas is on heating up honor I guess anyways that'll end shortly so you won't have to hear this weird noise too much longer so these boards are all done and I just need to make the cables so I have quite the assortment of ribbon cable this is all the standard spacing stuff that you find on a floppy or IDE cable so if you're making one of these for yourself and you don't have a roll of this cable like I do then you can either buy something from Aliexpress or just take old IDE cables and peel them apart now I'm gonna use this rainbow cable because I just love how this looks this is so 70s to me retro feeling but I will just peel off the amount of conductors that I need for the length that I need and then will crimp these connectors onto the ribbon cable so we need to figure out how long to make the cables the user port is on this side of the 64 so there's the news report the cassette port on the 64 is right there right next to it so a little short cable is all I technically need with that and then of course the furthest away are going to be these two ports here for the joystick controller ports now if I take a spool of my cable here want to make sure this little extra length is not tight so I need at least this much so so let's get a marker and I'm just gonna draw a line on the cable right there just to give me an idea of how long that is but before I cut any of this cable I want to see how long the runs are on a Commodore 128 specifically the 128 D the 128 D it's like a beast this thing is so big all right user port is in the same position as on a 64 so I'll connect that up right there and the two controller ports are right there on the side let's see if this is gonna be long enough to reach absolutely it will something that's odd on the 128 D though is while the controller ports are here and there's the keyboard port the cassette port on the D is all the way up in the front there so I'm gonna really need a long cable so there are two lengths of cables this is the one for the cassette so I'm gonna move that over the side so I don't confuse them basically of this one we want to count to 10 because there are 10 conductors on it and peel this apart even though this is a db9 we're gonna use a 10 conductor ribbon cable because that's what these I DC's come in is 2 by 5 so we're gonna split it apart and I made a little mistake and I split it so what the black wire a little bit but it's not the end of the world and you just you just peel it apart so before we crimp the connectors onto the cables we need to identify what is pin 1 and nicely the IDC connectors here have a pin 1 marked with a little arrow so there it is there as well and it's also on this part which is what we're gonna be crimping see the little arrow right there that's the one pin now fortunately on these db9 there's nothing marked spend provided a diagram that shows you exactly where pin 1 is and I don't know where it is exactly but the pin 1 on the cable is line up with that blue line so for the cassette cable it's gonna be exactly the same he's very clear with the way these go on so you just have to make sure that the colors of the ribbon cable match and that these orientation of these two connectors is exactly the same both ends and matches the picture all right now I use a vise like this you could use a tabletop type that is portable but this one is actually attached to my bench here this other workbench and there's a special tool that's designed for crimping these things you know I don't have that tool and there's this different dye for each one of these sized connectors and you know that I can get expensive if you make a lot of cables is definitely worth it all right let's start with the cassette one so you take the IDC connector and you have two little pop the little cover off if it's on there if you have an existing cable you have you can carefully prise the little prongs out and pull it apart and actually you know to make a new cable you can peel these off but these were brand new ones from China so if you notice there's little prongs there there little V's and the wires line up perfectly with that so you just sort of line that up and then you put the cap over it this little cap here you slide that over that and we're gonna put it all in the vise and clamp it down and that will basically push the conductors on to the little prongs sometimes I find it easier actually to slide the little thingy over partially and then you feed the wire through and it's just in the vise there if I move this get a little light and then as I close the vise it's actually pushing the wires onto those little V's and making connection now I turn this too much it will crush the connector so you don't want to do that listen very carefully and it will click in right in here it click I'm just gonna take it out give a little inspection well I think that's good enough I think it's on there with the 9-pin countries I bought these only have nine spaces in there so one of the wires of the 10 conductors see this purple one is off to the side and I'm holding this and I'm going to crimp this down in the jack vise I mean luckily I have multiple of these connectors so if I screw these up I can just try again so I recommend you don't buy the exact amount you need buy some extras so I recommend after you crimp these that you check for continuity hook everything up we just connect it up to the various boards he made the connectors so you can't screw it up and we have the keyboard connector now I did tone these all out so essentially put pin one here and on the bottom of the board with the connected pin one I had some issues because seems that the wire I bought this ribbon cable is in quite the right size it's slightly too small so I had to split the wire slightly just just so when it went into there it would align correctly and didn't always make good contact well since this harness is designed to be used on a 64 that's already pretty much working you're just testing all the i/o ports but you know you should have a blue screen so make sure you have all your cables hooked up correctly that you get there we go basic so I know that's working and I'm going to use this diagnostic cartridge I have this has dead test and the regular test the one that matches the harness on here you just have to change the dip switches I use this a lot during my 64 troubleshooting series plug that in make sure that it works good we got the Diagnostics running and why don't we connect this up so this goes on the user port and these are really tight connection that goes there here's the cassette cable with the very long ribbon cable okay let's connect this up and then we have these two controllers it says on the board controller one so this is controller one roller port one and this one is controller port two wow you know what I've made these cables pretty tight lengthwise thought I had enough length but let's take this off because we are going to need to put the loop back on the keyboard well there's the keyboard connector right next to the ZIF socket and here is the loopback connector now it's gonna be a little tight because of the ZIF socket but it shouldn't be an issue just push that on there like the LED is right there but it's not touching the pins underneath plug in the video cable again and here we go hopefully no smoke comes out well right off the bat no I see show is bad oh I forgot to make the IEC connector and I didn't even plug that in all right well serial port is bad because I forgot to make the IEC it's loop back and then it's showing one of these is bad but I wonder if that's related as a serial so let me let me create that connector and we'll run this again okay so this is the IEC connector that I'm gonna open up and solder inside I need to push this down and then you slide this cover off and then before we put it back on we're gonna bend that back so good excuse to use helping hands I have the connector in there and I'm going to use some of this off cut wire let's try and get this hot all right the other side if you get these pins too hot it will melt and they will slide around and kind of you can push them out of alignment push them out of the connector entirely all right so now we're gonna do the bottom two pins it's pretty crappy I'm just gonna lie that there see if I can get this okay and I'm just gonna trim off this excess so there we are the pins are connected the connectors back together let's test the continuity top two pins yep and these two pins all right time to test this again so we have the serial loopback adapter let's plug this in there we go everything else is connected and let's power this on trying to fix the Mauri by making the camera slightly out of focus so far so good let's see how this goes oh yes look at that everything is ok now just the interrupts test that's okay so no chips report bad the city's testing now why don't I unplug one of the control port hold the control port cable off see what it does Oh interesting control poor VAD but down here which was blank it popped up forty sixty-six at you twenty-eight bad which is the chip right here obviously that has to do with the joystick ports and I bet you because I unplugged one cable it thinks that chip is bad as opposed to the sixty-five twenty-six that controls the joystick ports well that's gonna be it for this video a huge thanks to spend for sending me those PCBs so I could finally build my own diagnostic harness I've been wanting one of those for a long time because as you guys know I troubleshoot and test lots of Commerce 64's on my channel and it's good to know that they're fully working without me having to plug in a bunch of joysticks and peripherals and test everything I did spend some time plugging that harness into my own commerce 64's looking for one of them that maybe had a hidden fault that I didn't notice but unfortunately I didn't find anything now we all know that Commodore 64 is break a lot though so I'll probably have a fault in the future on one of those machines which will lead to another troubleshooting video if you liked this video I'd appreciate a thumbs up if you didn't you know what to do thumbs down subscribe for more videos and hit that notification bell if you'd like to be notified when I upload new videos put your comments and suggestions in the comment section below and thank you very much for watching goodbye [Music]

Channel: Adrian's Digital Basement

Views: 33,176

Rating: 4.9651217 out of 5

Keywords: Commodore, C64, Diagnostic, diags, soldering, vintage computer, retro computers, 586220, CBM, C128

Id: szSzA6T4Kdw

Length: 25min 41sec (1541 seconds)

Published: Sun Dec 01 2019

Reddit Comments

[u/Orbitaller]

Why do the things I search for a week or two ago suddenly turn up on reddit or YouTube at an alarming rate? I'm on to you big brother! I'm going to break free! I'm going to free my mind!!! YOU'LL NEVER TAKE ME WITHOUT A FIGHT!!!!

Ahem, anywho I'm saving this to watch later! I've got the tynemouth project page for this store harness bookmarked and I'm looking for some free project time to start this myself. Hopefully some new or useful information here!

[u/technoph0be]

Adrian Black you are the freaking MAN!