Another left for dead machine: a TRS-80 Model II #septandy 🕸🕷🐜

well hello everyone and welcome back to adrian's digital basement it's september so i'm gonna make a video for septandi i don't always manage to make these c themed month videos and that's because my video pipeline is such that it's sometimes months ahead when i'm working on videos and it would take a lot of planning and organization to get videos out in the right month to match up and i don't always do that but this is a trs-80 model 2 a really rough one here which you're going to be taking a look at on today's video so it fits right in with septandi so search for hashtag septandy on youtube if you want to see videos from other creators that deal with tandy type machines which are computers that were designed and released by radio shack out of dallas fort worth and sold all around the world well at least in the uk and australia in the united states and canada so anyhow enough babbling let's take a look at this machine so without further ado let's get right to it [Music] [Music] the trs-80 lineup machines all started in 1977 with the trcd model one i'm not sure it was called the model one of the time i think it was just the trs-80 but eventually became known as the model one as it was the first machine that radioshack released they follow up the model one with a model three which i've shown on this channel i think well maybe but i have one and there's a model for which i've definitely shown on this channel and there's also a 4p which is a slightly more portable version the trading model 1 3 and 4 were all aimed at the home computer market with the model 1 coming out in 1977 and being a competitor to the original commodore pet and the original apple ii the model 2 which you see here was radio shack's first attempt released in 1979 to produce a machine that was aimed directly at the business market according to wikipedia it was released for three thousand four hundred and fifty dollars this computer right here which was the equivalent in twenty twenty dollars of twelve thousand three hundred dollars this machine also runs a z80 processor runs at four megahertz and could either come with 64 or 32k of ram you might be noticing it has an integrated disk drive here and yes it's an eight inch disk drive this computer was not software compatible at all with the original model one or the three in the four software it was a totally separate line of computers like i said aimed at a totally different market this machine was also the first in a line of business machines that radio shack released i think there's the model 12 and the model 16 and there is the model 16b and all of those machines are software compatible with this original two and none of them are compatible with the other ones wikipedia has a pretty good article on the model 2 if you're interested in finding out a little bit more about this machine but in this video this computer is really in rough condition and i have no idea if there's even a chance that this thing works or can work so i think in this first video of what will become a little bit of a series i'm just gonna take this thing apart and we'll peek inside to see how rough the condition is because i think it's it's going to be pretty rough so unlike the original model one of course this has a built-in crt it's going to be monochrome i'm quite sure it's a white phosphor although i'm not totally sure there are two switches on the front here we have a power switch which i don't know if that even works and then there's a reset button and the reset button definitely i don't think works it's very floppy i love how it says trcd model 2 micro computer in pretty huge writing considering that's staring you in the face here is the eight inch disk drive which uh these things are pretty robust so it may work luckily i do have a spare one of these not from this computer but it looks to be the identical mechanism to this i think these were all made by sugar you push this button here and that should release the mechanism it does i think it would pop the disc out if there were one inserted in there this machine has a detachable keyboard which is detached there's a cable here unfortunately if i spin this around the keyboard is a little worse for wear looks like this is the din connector for it and it has been yanked out or snapped off and there's a break in the plastic right there there's a standoff that's was inside the keyboard that came out when i moved it so might have to epoxy that back together and the keyboard itself has a pretty big layout as in there's a lot of keys i am 99.9 sure this is a foam and foil keyboard meaning at the minimum i'm going to have to use those foam replacement pads from techselect to get this keyboard working again it's filthy but at least it seems to be in okay shape like it's not the keys move okay they're a little scratchy luckily with foam and foil keyboards once you pop the foam pads out take the circuit board off the back you can just wash this whole thing under the faucet with lots of soap and water unfortunately the badge is looking pretty sad here on the keyboard it's sort of a rubbery plastic and it has yellowed significantly the rest of this machine is painted so you'll see here on the edge of the keyboard it's very worn from wrists that were resting on this thing obviously this computer got a lot of use so that's good it wasn't just thrown away brand new it was heavily used um but yeah without repainting the entire case there's not a lot you can do about that at least the plastic underneath is gray and it's not white or black so it wouldn't it's not super ugly that the silver paint is missing now i'm kind of exploring this machine for the first time myself um the keyboard cable i think it feeds in i'm not sure if this has a mechanism like a an old vacuum cleaner where you pull the cord and it it feeds back in seems like it it could possibly go go back in we have a couple controls for the monitor down here i think there's a brightness and a contrast knob and they both are moving so they're not frozen that's good i'm gonna try to turn this machine around it's really heavy and i think that primarily is because eight inch disk drives are notoriously heavy as well in fact it's funny about the 8 inch disk drives the motor spindle that drives the disc that spins the disc actually runs at mains voltage so in the case of this machine of course 120 volts it's not software controlled so it doesn't like stop and start from a disk command like five and a quarter inch or three and a half inches do they're always turning but it's a really big chunky synchronous ac motor that basically is locked to the line frequency of 60 hertz here to spin the disc at the correct speed on the back there we go let's flip this around whoa it fell off the desk here there we go all right looking at the back of the computer this is what i was talking about with i'm not sure if this machine's ever going to work there is a lot of rust back here on the back panel um it's metal and um it's definitely seen better days so this thing here it says disk terminator for the trs-80 model 2. i assume you can connect an external floppy drive to this port right here and this is the terminating resistor pack when you don't have an external drive connected actually yes it does say disk expansion right here here it says parallel printer channel and this looks like an iec type connector and then right here we have two serial ports serial channels a and b there's a fuse and there's ac power and the whole plate really rusty and a lot of bug residue back here even the badge here it's definitely seen better days as well but there it is radio shack catalog number 26 4002 trs-80 model 2 and 120 volts 60 hertz and 198 va i think that's what it says which means uh probably around 200 watts or 250 watts or thereabouts now you might be noticing that the case here looks like it's not attached and that is the the case it was exactly like this when i received this machine it was missing the top screws here so i don't know what's going on if this thing's been gutted for parts or whatnot but let's crack it open and take a look all right i put on some gloves here because there's probably a lot of bugs because just on the back there with a ton of bugs let's just lift the case yep lots of bugger has to do inside of here it's little specks and whatnot so i'm probably going to throw this into the sink right now and let this soak in warm water well well that is pretty dirty in there there is a lot of spider webs and and whatnot um i'm probably just gonna have to take this apart anyways okay well enough i'm a little bit in shock but let's uh let's take a look at what we see in here so this is honestly the first time i've ever looked inside one of these machines so i'm completely this is all new territory to me now we can definitely see that there are expansion boards so it looks like there's a total of eight slots and i'm imagining that this thing probably uses some kind of a back plane i don't know if it even has a motherboard but maybe it does down below or we saw those ports and these things here are are just um option cards or something like that the dead bug situation in here there is a lot of eggs like spider eggs and things down there i think it's all old and desiccated but this thing clearly was in like a shed or garage or someplace maybe even outside i don't know that exposed it to a lot of bugs and they definitely took up residence in here now i kind of want to take out these expansion cards and the interesting thing is it doesn't look like they slide into a chassis here there's this bar that just holds them in place and once that's off you probably pop them out and lift them up to get them out of the case because obviously this part of the case is permanent that doesn't come off so i think i need to just take these things out so i can get a better look at what the situation is inside of here seems to be an eight millimeter nut now knowing radio shack there will be a really good service manual for this and i should probably be just looking at that as opposed to guessing at how to do this but hey you know what sometimes it's fun to kind of operate blindly i don't want to drop all these things inside don't fall there we go okay so this bar should come out there it is really quite dirty it's got some foam on there plastic on the top and we have a lot of spiders okay so we're gonna start with this board here on the left okay so i'm gonna leave that one because it's connected let's pull off the next one this looks to be 4116 so this is going to be 64 kilobytes of ram and i'm kind of imagining that it's possible to install multiple of these and maybe expand this thing beyond the 64k that's probably in this machine all right next up is this controller now eight and a half inch drives have 50 pin connectors that was not one of them but this next one probably is and needless to say i think because of age and or corrosion these boards are very very stuck in here so 50 pin ribbon here this is what goes to the sugar drive now it doesn't have any really additional signaling over five and a quarter inch disk drive so you can build a an adapter well there's that board now taking a look there is quite a bit of corrosion right here it's probably something that could clean up that's not from battery leakage or anything like that that's kind of why it was so hard to take this this connector off look at the um there's a line on there and that's because of corrosion but you can definitely see that water have been pouring into this computer along here and that would be through the vents in the top of the case so that's why i just don't know how well this is going to work yeah there's just corrosion all the way along here didn't look at the back of the other board but it says tandy corp 1979 here this is the back of the ram card there also says 1979 taney corporation and hopefully you can see in the camera there like there's a good amount of corrosion right there on that pin and uh yeah it's just a lot of filth on these boards maybe it'll wash off maybe all right let's see this next board so it had a connector that went to the front panel it looks like and let's see there's a big ribbon cable here so the corrosion from the water that's running down this thing makes these connectors really hard to get off luckily they're gold these are gold at least so when you look here you see zylog chips and you might think that this is the cpu board but i actually don't think so this one here is um who knows what that chip is i'm not familiar with it this board's in pretty good shape not a ton of corrosion on this one all right and lastly is this board which i've already removed you know what i'm going to grab a marker i'm just going to draw a couple marks on there just so i know how to get those back on all right so on this one i'm going to put two marks and on this one i'll just put one there was some slastic on here to try to hold these connectors on they are keyed differently so i didn't have to worry about the uh look at all this spider stuff oh boy um it looks like this one here it goes over the crt board so this is definitely the video signal and the other one it looks like it's going around and under the disk drive so i don't know could be that that's like the brightness and contrast not sure alright well clearly this board is the video display board so it's got a 6845 crt controller there it's got some video ram right here which is static ram there's a bunch of pine needles and that's it so i guess this other board here i guess one of these was the cpu i didn't recognize which one that was but i'm just not familiar with my zylog chipset part numbers so one of those must have been the cpu well now looking inside you can kind of get an idea for the debris in there look at all those see those little balls i think those are spider balls or something i i'm not totally sure but this computer clearly will need a complete disassembly and deep cleaning so i took the boards and i just gave them a good wash and scrub with soapy warm water a little bit of a soak as well a lot of filth came off of them definitely looks a lot cleaner at least while they're wet and i think just so i can continue to work on this i'm going to use this thing here a data vac and i'm going to just try to vacuum up some of the cobwebs and debris and stuff that's in here [Music] i really need to set up a better camera angle to get views inside machines from the top down over on this other bench because it didn't really show how much filth and debris was inside this machine which i was vacuuming up [Music] well it's a little bit cleaner but obviously the real way to clean this thing is to take it completely apart and yes i will have to hose it out but while i was vacuuming i noticed and i'm putting my hands through a bunch of cobwebs look at this is this normally something you find inside a computer um a maple leaf and no that doesn't mean it's because it came from canada it's because uh here in uh portland there are tons and tons of maple trees so there's a fan a big fan down there and the and i can see little pieces of more pieces of leaf that are stuck on the fan this was just sitting on the fan now the eight inch disk drive this is the chunky ac motor there and i can see a drive belt that goes from this motor to the spindle and if i reach down and i turn the spindle it does turn but it doesn't feel good uh the bearings are probably totally shot on this disk drive so you see this thing here this silver large thing i am pretty sure that this is the ac run capacitor for this ac motor but i do know ac motors that run directly on mains they do need a run capacitor i think a start and a run capacitor which might be what this is a start and a run so probably has several uh con connections to go to the motor i can see some some leads there but yeah anyways um the bearings are probably going to be garbage on this thing but i'm just going to continue taking this apart after a little bit of looking around on the machine it looks like the front panel comes off next so i started looking for all those screws that might hold the front panel on which includes some on the front and started taking them all out [Music] now even with the front panel screws removed there are several wires that go to the switches and the knobs that are on the front panel which you have to figure out how to disconnect as i had mentioned this was the first time i'd ever seen one of these computers before and definitely never worked on one or taken one apart so it was all a learning experience and was me figuring it all out as i went along [Music] the two knobs on the front there are little metal rings that hold those knobs into place instead of a usual nut on the potentiometer you have to push the potentiometers through those rings to release them [Music] i then removed the two screws that hold the power switch on so i could tuck that back in the chassis [Music] a little bit of vacuuming to clear out the plethora of dead bugs and other things that were around and a quick clean to the crt made this thing look a lot better well a little bit of cleaning goes a long way judging by the fact that there's like so many pine needles and leaves inside of this computer like here's another one right here another maple leaf a lot of spider webs uh this machine had to have been outside there's just no other way that it would have this much plant debris inside and bugs now it didn't get directly rained on so i have a feeling this thing was covered to some extent maybe it was under like a carport or something yeah the fact that there's so many leaves maybe the cover was off and in the fall like leaves would be blowing around in the wind and it would end up inside of this computer i still haven't exactly figured out how to get the chassis which obviously this thing is mounted inside of the plastic shell just goes around the chassis i haven't figured out how to get the chassis out yet you can see the disk drive here there's the spindle motor and actually it turns a little bit better than it was when i first turned it it was definitely stuck but just turning it by hand has got it going so maybe that can actually run at normal speed now it's all about figuring out how to get this chassis out of the plastic case there are definitely screws on the bottom that you remove to do that but it's not clear which are the screws that do it because some of the screws are for holding down the disk drive for instance or other parts to the metal chassis so it's just a little bit of trial and error a little bit of a lift on the chassis confirms that it's starting to come away from the bottom but it's not quite released most of the screws were pretty easy to access but one of the screws for removing the chassis is sandwiched between the power supply and the crt board and is very difficult to get to so the chassis is loosened and now all that's holding it in are the ac cords here looks like i have to unscrew the iec input and take the fuse holder out the screws on the back of the computer are really rusty so hopefully this actually comes out okay that one came out so okay there's the mains input disconnected i dropped a washer uh the fuse holder i'm gonna just unplug this it's uh it's got two spade connectors and i don't see any other way to get it off there we go so i need to figure out how to get this out of here and i think if i lift from here it should come out maybe there we go wow it's heavy it is so heavy so basically other than the very dangerous 70s wiring here of like exposed mains this could run like this you don't need the rest of the case at all to use this so right here this cable i unplugged it off the disk drive it comes directly i guess it comes off the power supply but i'm assuming the power switch on the front actually uh turns this off and on okay so this plugs in right here which is where the start run capacitor is and the motor now look at this uh my tool here i knew that was going to happen i had to use this really long screwdriver with extensions and sockets to get to that screw that was down there that was holding this chassis and unfortunately um all the screwdrivers i had would not reach all the way down there what a dumb design that it's sandwiched between these two boards i don't know how well this is going to show up but there's a little terminal block down here for i guess mains power distribution and it's all rusty all the screws right there rusty but i'm assuming this is full mains voltage exposed just right there like it's not covered or anything i mean i know this is the high voltage analog board right here so you shouldn't be poking around there but it's still just it's so funny that's such a thing of the 70s like it's just not something you would ever see in much newer stuff that's for sure all right so i'd like to try to get my socket out between these two boards i think the best thing to do is take this screw off here or attempt to at least this holds the crt driver board on and if i do that i can bend the board out of the way it's held on by four screws and standoffs everything is very corroded there we go all right there we go there is my socket what i want to do is just take out the entire power supply slash crt board i'm pretty sure is held on with a screw down here let's get this screw out everything is just very inaccessible let's get this screw out and i think there are two screws plus the one that holds the chassis into the case that hold the power supply and analog board down and yes that is loose now it appears that the crt board is very much permanently connected to things here like there's these are soldered on i have to take the deflection yoke off if i want to uh pull this away and the problem is the ground lead here oh that does come off at least okay okay these are power supply board connections so this would be mains i guess and this is dc voltage right here and this cable here appears to be a connection to the crt board and there's a ground lead down here amongst all the incredible amount of dead bugs all right now i do have to remove this deflection yoke oh yeah that's very crusty oh i can't get that off though because this cage board is in the way this whole thing is so like uh it's like you obviously have to remove the cage before you can take the crt out and these wires here are soldered onto the board there's not a connector oh you know what there is a connector but i i don't want to touch that that's fragile all right well next out is the cage then looks like it's got four screws you have to use a really long screwdriver just like um i've been doing okay and before i can get the two screws there on this side i think i need to uh take the disk drive out like i don't think it's possible without doing that so let's see how do we get the floppy out all right so there's some very big screws down here i kind of assume to have i already took one out when i was trying to take the chassis out wouldn't be surprised if there's four okay there's that one uh there's one on the front here this is for the disk drive oh come on it's really tight and there is one on the top right here is this free no it's not free there's still one more down between the cage oh you got to be kidding me so the bolt that's left is in between the disk drive and the cage and it is so deep down in there that i can't even this monstrosity here is not long enough all right uh all i have that might possibly work is this but this might be too thick let's see oh it's not okay this is ridiculous these tools you need to take this computer apart what really has me questioning this process i don't even know how i'm going to reassemble this stuff um my socket thing here is not magnetic this might be like a one-way process a one-way ticket for this trs-80 might as well get the screw out for the cage while we're at it the cage what's happening here it's got like a power cable on it uh okay let's get the disk drive off this at least i can unplug these connectors that one and this is dc power and this should come out now i think there we go that's the uh eight inch floppy drive whoa whoa and there is the cage you can see there's a little maple leaf propeller thing there on the fan okay this is the power switch here it's in a little plastic holder now what's preventing removing the cage are these things here one's holding the high voltage anode cable and one's holding like a uh i guess the focus or something so how exactly do these come apart i don't i don't know maybe it's been so hot it melted i don't know i'm very tempted to just cut it no i got it okay there we go that was so incredibly fiddly okay and we're not home free yet because these are zip tied on this is like a one-way assembly process really they didn't obviously this was uh not a home computer so it was not designed to be serviced by regular folks you know this would be you'd call it i guess a technician i guess i don't know and then we have a dc cable on the back plane which obviously gives it plus five minus five you know all the stuff it needs for the ram 12 volts there it is there's the cage the uh not the cage well yeah it is a cage but there's the back plane and as you can see good amount of corrosion in there but the pcb it looks fine i'm gonna say that's fine definitely some rust on these nuts back here all right and i think we are pretty much almost free to go to get this off so i can take this off deflection yoke should slide off now there we go i took this piece of tape with it high voltage cap here is looking a little worse for wear i'm just gonna grab a cloth try to clean that up a little bit here's some wd-40 sprays two ways oh i didn't even notice you could spray it this way okay i'm gonna do that oh yeah look at that look at that it takes a all that gunk right off there we go the anode cap is off just gonna wipe down this around the here where it's all sticky so at this point i can actually remove the power supply board just make sure everything is disconnected and the crt driver so i can give this thing a closer inspection there's the power supply from the trs-80 model 2 and there's the crt board complete with pine needles and tons of dead bugs so that was way more work than i anticipated um i think i'm going to end this video here and i have a lot of cleaning to do so before my next video on this machine i will have probably just taken apart the rest of this there's nothing much more to it right just take off some screws and really clean off this bottom plate uh and maybe replace this distribution block here which is all rusty you know that kind of quick maintenance stuff so in part two i will probably test the crt we can test the crt and the driver board see if it runs the crt properly i can probably generate some sync signals i will have to look up what video signal this thing runs at but it's all in the technical manual maybe we can check out the disk drive which i'm pointing to on the floor there see if that's working is gonna run maybe hook it up to a pc something like that clean up the this drive cage board and finish cleaning up the circuit boards that were in there and of course that all those ribbon cables that were hooked up to those ports i really need to take that out as well and try to clean that so yeah there's still a ton of work to do a ton of work to do on this machine and i guess my biggest worry is that i'm gonna forget how to put this thing back together it's like a puzzle so i should be able to figure it out anyhow that's it for my septandi video on the model 2. so if you liked it thumbs up if you didn't you know what to do and if you have experience with these machines if you can recommend software to use if this thing ever does work maybe there's some good software i can use with it i actually have some blank eight inch discs so it's quite possible i could hook the drive up to a pc and image a downloaded image onto an eight inch disk or i could wire in a gotek as well gotex i think can hook up to an eight inch drive there's some extra signaling on these that maybe the gotek can't emulate i'm not sure i have to read up on that there's a lot to read up on this machine because like i said i know pretty much nothing about it so there we go all right that is going to be it oh wait i've almost forgot to say thanks for my patrons their names are scrolling off the screen if you want to be a patron you can do so at the link below check out the second channel all that stuff okay for now for real this time it's the end of this video stay healthy stay safe and i'll see you next time bye [Music]

Channel: Adrian's Digital Basement

Views: 55,739

Rating: 4.9531283 out of 5

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Id: x8DfSg7oMWg

Length: 34min 31sec (2071 seconds)

Published: Sat Sep 25 2021