 This thing is a Vector MZ. I picked it up at the Vintage Computer Fair over in the Computer History Museum and it's basically an S100 bus system. So this is the backplane over here. It came with two disc drives and there's a power supply over here and that's really all there is to it. So this was created by the Vector Graphic Company. You may be familiar with them from their insanely overpriced vector boards. I think this thing used to cost a thousand or maybe a couple thousand. Again insanely expensive. But basically that's all this is. It's an S100 bus backplane. So here is the disc drive card Vector Graphic. That probably means it cost about a thousand dollars on its own. I will not be powering those up. In fact I'm not even certain this is going to be compatible with my S100 bus system. I do know that there is a voltage regulator over here which is a looks like a 7912 so that's a negative 12 volt regulator. So anyway I basically wanted to rip out this power supply and put in an ATX power supply and I just want to see how easy that is to hook up to the backplane. Now the interesting thing about this backplane is oops if I tilt it you can see on the bottom and maybe even along the top you know you can see resistors. So this is basically an actively terminated backplane. The problem with S100 bus backplanes is that there aren't grounds between the signals so the signals do get kind of noisy and apparently the active termination which consists of a resistor going to plus and a resistor going to minus helps in that regard. So anyway I am going to take a screwdriver and start removing these capacitors. They're definitely fully discharged. That's always a good thing. Let's just go ahead and remove these capacitors out or at least unwire them and in terms of the wires we've got these green wires which are obviously ground. These green wires which are also obviously ground and then we've got these red wires and these red wires which all go to here. Now to me red means plus five. Let's see we've got some purple wires and we've got some yellow wires so if I had to make a guess I would say that the red wires are the plus five or actually plus eight. The purple wires would be the plus twelve or actually plus sixteen and the yellow wires would be the minus sixteen and I could be totally wrong. Oh yeah and this must be a negative voltage because ground is connected to the positive so at least I got that one right. Okay so now we've got all the wires removed from the capacitors so these are these boards here so I'm just going to tuck over there this I'm just going to tuck over to the side. Okay so now the capacitors are affixed to the bottom using some kind of nut and it looks like there aren't any screws on the other side so I'm going to need a nut driver to remove those. Just get rid of all these nuts. That's a pretty big capacitor. It is a 28,000 microfarad 25 volt DC power cap garden grove California national capacitor made in USA. 54B80-8031 so could that be 1980 week 31 and I'm dropping washers into the slots. That's not great. The only problem with this is that the nuts tend to get stuck. Why don't I do this the right way? Okay so this one is the same type of capacitor the same value 8031. All right capacitor okay and this one is different it is 60,000 microfarads 15 volts DC so that tells me that this can't be the 18 volt bus supply it's got to be less than 15 volts so this must be the 8 volt bus supply so I was correct these other ones are 25 volts which indicate that the plus and minus 16 volt supplies would be regulated by those capacitors so down here it's hard to see but these square things over here are diode bridges so those are the rectifier diode bridges to rectify the AC voltage that's coming out of the the transformer there should be I thought there would be three of them but I only see two there would be one for each voltage so maybe there's one hiding somewhere so those need to be removed as well so I'm just gonna unscrew this I found what appears to be that's interesting this is something that goes on the edge of these cards kind of like this and then this let's see I think it goes like this so it so it lays flat against the card like this but then when you want to remove the card you open this up and press down and that sort of forces this card up it looks like the rectifier goes to a bunch of wires that are also zip tied so I'm gonna have to remove the zip ties okay so this is the rectifier does it say anything on the side it does it says gi looks like general instruments that's interesting KBPC 25-02 and then over here it says 8038 I guess that is a date code also so I would date this to the second half of 1980 all right that's the rectifier it seems to have a probably a mauve an MOV a metal oxide varistor so that would be for protection it's it's on the AC side which makes sense so that's one and it's pretty much the same thing so that's this side of the transformer so now we deal with the other side of the transformer it looks like I can probably take the transformer out and then pull these wires off I think I'm just going to remove those zip ties can always replace them so I looked it up online and apparently the mz the vector mz did actually come with some with a CPU card and a monitor and possibly a printer and the whole thing cost $4,800 back in 1980 like I said everything having to do with vector graphic was hideously expensive and I would always look in catalogs at vector graphic prototyping cards and they were always always just insanely expensive and I definitely could not afford those all right I think what I'm going to do is remove the fan that way I might be able to get to some of the transformer connections besides we're not going to need the fan and the reason that we're not going to need the fan is a we're not going to have a crazy huge power supply and B we're not going to use linear regulators to regulate the voltages we're going to use an AT power supply an ATX power supply which is a switching power supply and it's very efficient and it's got its own fan anyway so let's go ahead and remove this so here we've got nut followed by a lock washer followed by a regular washer so I don't know I mean I've heard these split washers or split spring washers or whatever I've heard that they basically they don't do anything because once they're compressed they don't actually supply any force so I don't know there was there was one vibration test on YouTube that they showed where these split washers didn't actually do anything under vibration and I think NASA even published a paper basically showing that that they were completely useless and that nobody should use them really now some of you may be yelling at me because I'm taking apart this vintage thing that was really expensive and it's quite rare because they were only 5,000 made yeah maybe I don't know hey I'm saving all the parts I'm not like cutting it not cutting it apart at least not yet if I can get this fan out now I guess I could understand if if this were some you know if this were like a board like this that was I guess fully functional and I would be like ripping it apart for the chips I don't think I would do that I might do that with a no-name card but you know I'm not going to rip this apart likewise again I'm not ripping anything apart I'm just disconnecting things and replacing things I can always put it back afterwards okay I'm going to need to use something a little beefier hopefully that should give me enough room to do something no back a little bit so we lift the transformer out okay there we go so let me just pull this so there is the huge enormous transformer okay something fell off that was pretty huge I'll probably just end up putting all this hardware in a baggie to keep it a little magnet this screwdriver is a bit too thick okay so there's the fan connected to the enormous crimped terminals there's another zip tie here that I don't need okay so where does this go this goes all the way to the back where there is a key and a reset switch so there is one wire that goes to the reset switch the other wire goes to this jumper here presumably that is maybe the reset line and the third one connected to the reset switch is connected to a ground for which I will need a Phillips head screwdriver put this screw back so the next question is how do I get this reset switch out do I even want to probably not the reason why I might want to get it out is that there's also this key well I think I'll leave the key in as well so the key goes to a fuse in the back which I don't need and then to an IEC inlet which is the technical term for where you plug the power cord into so I don't really need any of that stuff so what I'm gonna do is I'm going to remove the zip tie the other zip tie so the key one end of the key goes to one end of the fuse I'm just going to cut that wire because again I can always re-solder it pretty easily and the other end goes to this thing this complex so let's see if I can just unhook great alright so the fan is now out this fan is a rotron rotron airflow so it looks like it was mounted this way so the air would flow in alright so what have we got left this was the auxiliary don't need that anymore I'm now going to pull the hardware out this is a non-magnetized screw these are both non-magnetized screws done okay so that has totally disconnected the entire power supply now the next thing we need to do is look at the power supply for this so rather not the power supply but where they get connected to so I move these cords out of the way these cables oops there's a screw so we see two wires going down underneath here one of them is yellow and one of them is purple sorry that's three wires yellow purple and red obviously plus 8 and plus and minus 16 and the ground was connected here so clearly what we should do is unzip tie this bundle right here and then find out where it comes out over here and then we can hook that up to the power supply so let's unzip some of these I want to be careful but I don't cut any of the cables all right so here's this unzip tie this instead appears we've got a few extra wires coming on it onto this harness wire harness okay so there's that and there we go we've got our three wires that we need for the power supply so I will probably check this to make sure but I'm pretty certain that the plus 8 is going to be connected to the red wire why don't we just look at that again I'm not sure which side is which I mean I know that this is the ground side and this is the plus 8 side oh look at this there's actually a convenient test points ah okay these screws are where these wires must be connected to and they're very nicely labeled so this is going to be the plus 8 and the yellow is going to be the minus 16 and the purple for completeness is going to be the plus 16 done okay so we can connect that up to our power supply and we will have power now one interesting thing is that there appears to be a regulator in the corner over here I'm going to have to remove that the regulator is there let's see what it says the regulator is a 7805 so this is a five volt regulator so we don't need that in fact what we could do is we can just connect the two outer legs of the regulator because number one we don't need the regulator and number two I don't think the regulator will will use up any current so maybe I'll just leave it there and well no no I think I'm going to desolder that the reason that I'm going to desolder it is that if I connect a wire between input and output of this regulator and then later on I get rid of this thing or you know want to restore it I might actually forget that that that wire is there it's a very easy thing to miss so I'm definitely going to have to desolder it now in order to desolder it I'm going to need to remove the back plane what's this thing this thing that's neat so that's to um stabilize these sides so I'm going to need to remove the back plane and then flip it over and desolder so let's go ahead and do that okay so there we go that's what the back plane looks like on the on the other side so we've got the connections here of course this is nicely labeled ground this is labeled plus eight let's see so the greening appears to be flaking off here that's interesting over here and most of the green has flaked off on here interestingly there is no sign of those green flakes in the box itself interesting yeah so we've got resistors on here so those resistors are the ones that go to plus five on this end we've got the resistors that go to ground so that basically means that if nothing is connected to this then those pins should be floating at two and a half volts and that's basically what an active termination is looks like my dryer is done okay um and then we've got these three resistors over here now let's see where they go interesting so one of them goes from plus eight to ground and the other ones are for the plus and minus 16 volts i guess they are to provide a load this resistor is a 100 ohm resistor and these resistors look like 820 ohms it looks like anyway i'm going to go ahead and desolder those components and then put this back okay so i desoldered those components and um i also had a closer look at these resistors and in fact for the ground side that's this side the resistors are 470 ohms and on the plus five side the resistors are 330 ohms so 330 in parallel with 470 is about 194 ohms so each one of these resistor dividers would be drawing about 25 milliamps of current and at five volts and i counted up these resistors these resistor dividers and there are 42 of them so we're talking about 1.08 amps uh just for the active termination so that's okay the atx power supply can supply way more than that so this board is actually ready to go so now i just need to figure out how to mount the atx power supply inside this so i have there's the switch the inlet the fan and the power supply cables this doesn't really fit anywhere and there's actually no power switch on this thing unless the the key is the power switch yeah it says power on it okay well i suppose what i could do is take this apart because what i really want to do is i've already got a power inlet so that would be this the key would be this button uh this is just a voltage selector there's probably a fuse inside here so i wouldn't need the fuse and the fan i could probably uh i could probably 3d print a mount for it so that way i could basically bring this and this out and then just mount the fan mount this thing like right over here print in the thing three hours oh man okay so i have the power supply now mounted the fan grill is mounted on top of there all right we can see that i've started to wire up all the power supply wires this is the actual power supply connector i've cut off the plus five volts the plus 12 volts the minus 12 volts and a bunch of the grounds and i've cut off this green wire from the power supply connector this green wire needs to be connected to ground in order to send power out to the cable in order for the power supply to send power out to the cable so this is basically your on your pc this would go to your power button but there is actually non switched five volts i think it's this white wire or possibly this purple wire or maybe even this gray wire one of those anyway so obviously that's just a standby power that's called vsb or standby these red wires are all plus five volts so i have the plus five volts from the power supply wired into the plus five wire or plus eight wire that goes to the backplane this blue wire uh i believe is negative 12 volts um and that goes to this yellow wire and the yellow wire from the power supply is actually plus 12 volts and that's going to go to the purple plus 16 volts wire that goes to the backplane so now i've supplied the backplane with plus five minus 12 and plus 12 all right so what i've done is i've set up my voltmeter over here and i have connected it to so actually these are just screws and i'm just touching that screw uh with the probes and this screw over here all of these screws on the outside are connected to ground so it's just going to hang out somewhere over there just like that so hopefully that's touching enough that i can get some sort of a reading now i'm not sure i'm pretty sure so that so the the key is now like this and i think if i turn it like this it will turn things on so now i just need to find a cable to put on the front okay so i have a power cord and i'm going to connect it and see what happens great okay nothing should happen now i'm going to turn the switch and excellent the fan turns on and we have five volts on the eight volt rail which is correct let's take a look at the other rails this is the minus 16 volt rail which is giving negative 11 volts and the plus 16 volt rail is giving approximately 12 volts so this power supply seems to be a little weak in the uh in the negative 12 region so well since that power supply was really bad um i decided to buy another power supply this one was just $18 it's a triple power supply it takes a c in and it gives out plus five volts plus 12 volts and minus 12 volts plus five volts at i think around six amps plus 12 volts at 2.8 amps and minus 12 volts at around 0.5 amps and i hooked this up to my electronic load and the five volts was pretty much rock solid uh all the way up to its maximum uh the 12 volt line sagged probably about four percent and the minus 12 volts uh sagged about minus uh sagged about six percent so you know we're talking about four to five hundred millivolts on a 12 volt line which is actually pretty good so i decided to just hook this up and as you can see it's very small and it also does not have a fan so i hooked up the original fan over here uh not only that but it has no switch it has no fuse so i hooked up the original fuse which is underneath the fan and the switch which is on the front this key so uh let's just fire it up and see if it works all right so here i have hooked up the power in the back um and the ground is just attached to the rails uh this this metal railing and that should theoretically be connected to ground which i can check by simply checking continuity so let's go to vaults and turn this on okay okay and now maybe you can hear this humming that's the fan and there's actually a light on the power supply so let's check the five volt rail there we go we're getting 5.068 right on the money and the negative rail is negative 12 and the positive rail is 12 so indeed uh this power supply is working just fine and again i tested it with an electronic load so uh we should not get any voltage drops or not any significant voltage drops when current is drawn from the power supply so uh that is just about it for this s100 system the next step of course would be to get some cards and start plugging them in which will be the subject of future videos making cards to put in the s100 system thanks for watching and don't forget to subscribe on the next episode of building a retro computer that generates a lot of heat i made a mistake over here you're just going to be sitting there feeding sovereign forever the terminals sort of go up the side i don't want to go any lower because then it becomes difficult for me to solder and the reason for that is that other boards in the system can pull that line low why am i using a brown plate once my soldering iron heats up a little more