Breathing New Life into a TRS-80 Model 4 with an LCD Screen!
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- เผยแพร่เมื่อ 6 มิ.ย. 2024
- I broke the CRT in this TRS-80 Model 4! Now I have to fix it. I designed a new bezel for an LCD display panel and the results are amazing! I also fixed the floppy drives and replaced the cut-off power cable with a socket. Thanks to PCBWay.com for supporting this video!
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Video Where I Found The TRS-80 Model 4 - • So Many E-Waste Finds ...
This site contains affiliate links for which I may be compensated with no extra charge for you. Thank you for supporting the channel!
3D Printer Files For Bezel - www.printables.com/model/8757...
12.1 Inch IPS Display Panel - amzn.to/3WDeRV3
3M Dual Lock Tape - amzn.to/44BcPqz
Chapters:
00:00 - Schematics
03:58 - Installing RGBtoHDMI
15:37 - PCBWay Ad
16:39 - Testing Video
18:12 - Fixing Floppy Drives
21:33 - Replacing Power Cord
23:05 - Removing Old CRT
30:15 - Testing 3D Print
32:40 - Installing New Bezel
47:39 - RIFA Madness
49:53 - Final Testing
Music used by permission:
“Fakebit World” by Malmen
/ malmen
"Welcome To The Chemical Plant" by Pete Frogs
Other music from the TH-cam Audio Library
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#Retro #Computers #trs80 #tandy #radioshack - วิทยาศาสตร์และเทคโนโลยี
So your new monitor has more computing power than an entire radio shack store in 1983.
You would think that display had a an LED backlight so no HV power supply. Fluorescent tubes were old technology 20 years ago... and this display is very much behind the curve tech wise and longevity wise. I was replacing backlights in industrial screens for production many years ago because we foresaw the problems with them in our designs.
I have a model 3 that's been sitting in storage for years. This makes me finally want to get around to restoring it
All the vintage tech youtubers need to buy a decent set of hand files. You can drill out the corners and file to your lines so much easier than trying to control a dremmel spinning at 1 million rpm :)
How do you find one that is decent and won't break right away? Any reviews?
@@FadkinsDiet If you're dealing with plastic you can use anything. They should be able to cut steel. Buy the cheapest set of flat, round, half-round and whatever. You remove plastic and aluminum and steel with control. Buy cheap and if you use it enough to dull it buy better. You need a flat file. A triangular file (only way to make square corners) and a round file. That's it.
The contrast of the TRS-80 and a modern LCD is stunning.
Really enjoyed the video. A few comments: 1. Matt Boytim has designed an FPGA video adapter that is cheaper and easier than using an RGB2HDMI and it still offers HDMI output and doesn't require motherboard mods and it auto switches for M3/M4 mode on a Model 4. I also have a through-hole PCB for it for ease of building. 2. Model 3 mode on a Model 4 machine is not identical to a Model 3's real output so that might explain the dot clock issue. 3. Jay Newirth makes a modern replacement PSU that is stronger than the original.
There used to be a company called Langly St. Clair. They offered a replacement Green & Amber replacement CRT. I swapped out my original b/w RCA tube with the Amber CRT when I was 12. The Langly St. Clair screens offered lower radiation and an anti-glare finish. My second mod was swapping out a defective Z80 with a NEC V20 processor. Other updates included adding the RS232 board and upgrading the RAM. That PC was a big part of my childhood and, unfortunately, has gone onto Computer Valhalla.
I have a TRS 4p that I like to play with and I like the idea to be able to switch between a V20 and the onboard Z80. Was it just a simple cpu swap or did you need an adaptor?
This is the first time I have heard sound out of a TRS-80! I had no idea that was even possible; Very cool.
Yeah. And it sounds pretty decent, too.
Sound was made by TRS-80 I/III/IV via the cassette audio out so it was very CPU intensive. Most people think it was '1 bit' as in on or off but in reality there were 2 bits of a port dedicated to producing the audio. So long as you didn't want to do anything else at the time you could produce polyphonic audio. The official ports of Frogger actually had better attractor mode audio on the I/III/IV than it did on the COCO despite the COCO having a DAC. There are alternate ports of Frogger for the COCO that actually do show off what can be done on that hardware.
make more model 4 content any thing you make regarding the TRS-80 I will definately watch.
This is by far the best modification I've ever seen. Makes me wish I had the technical and manual skills to pull something like it myself.
RIFA Madness! My favorite movie! Don't smoke the RIFA, it's bad for you!
Maybe a 3D printed bracket for the IEC power power socket, including a push button for the RetroRGB control, would be a good mod, as it would look more integrated.
I prefer the amber screen. Takes me back to my Hercules GCA days.
This BROUGHT me to your channel! This is the bee's knees. All the flavour of the TRS-80...and none of the weight of the CRT. I hope you'll enjoy doing more with this project. Now...I'm off to see WHAT you did with that Sony Trinitron flat panel conversion! Aloha!
I've always had a love for the amber crts. You are right that the color on that profile needs some adjustments.
That looks great, much better than I expected. I'm glad the magic smoke was just a Rifa.
I'd love to see how that display handles 80x24 mode.
I have had a Model 4 sitting open on a bench (with a good green tube) for 4 years since I'm paranoid about breaking the tube when I reassemble it - so I can feel your pain.
It looked to me like the Defense Command game was running in 80x24 mode.
Words cannot explain how much i hate working on the model 4 due to the CRT. So cool that you were able to swap it out!!!
Really fun project. Looks awesome.
That was cool project! I like seeing you restore the older hardware.....grin
Awesome mod! The Model 4 looks awesome with that new screen! Great job and awesome video! If my tube ever goes out on my Model 3 I might try this mod on it as well. Thank you!
Wow, this is most impressive. Well done.
I guess unless someone starts making CRT's again this is what the future of retro computing is going to look like. Also, I never thought I would see that clip from Planet of the Apes in a computer video, but it happened.🤣
Good Job!!
I miss the CRT but this at least gives the machine life again.
Nice mod. However, avoid turning the computer on while the disks are in the drives and latches closed. It can corrupt the disks. It's better to turn the computer on without disks, then insert the disks, then press reset. You can also just open the latches before turning on if you want to keep the disks in the drives.
Great video! The final product looks beautiful! When I saw the screen image 14:12 first thing I thought of was a jail bar interference effect you get when video modding some retro game systems like the Mega Drive.
Me too
Super cool!
This is great. I learned to program in BASIC on a model 4, so this is really nostalgic to me. -- FYI to get the sound working back in the day, you didn't really need to "modify" anything, a lot of casette recorders had a "monitor speaker" built-in -- so you would just hear that sound coming out of the monitor speaker. I think the speaker was meant for troubleshooting issues with saving and loading? -- But developers used it for making digitized sounds too! -- I had that same game too, and I was blown away that it could talk when I first heard it back in the day! -- Of course you could get a DIN breakout cable and plug it into the aux input of a stereo as well (I ended up doing that for gaming). -- But that was probably less common. -- Strangely, I remember having an IEC power jack on the back of my Model 4 system. ... it's not just a vague memory -- I'm like 90% confident it had that already. Maybe my system was modded. Or maybe they did that for some of them? -- I'm not certain. -- It's possible I could be wrong though... But I have a strong memory of it? 🤷
With curved LCDs being a thing and CRT emulation shaders for e.g. DOSBox getting better (on 4K-ish screens at least, from what I gather), I'm wondering if we'll eventually see faithful bulbous CRT replica panels that are hard to tell apart from the real thing. Would require some beefy hardware on the converter, though.
I can totally see myself trying to hack one in Fallout!
Lookin' great, man. Yeah, go for broke with the FreHD. This is what I call "retro without pain." Modern components are so much simpler to work with, and can really extend the life of old gear like this without too much expense. (Glad when the Rifa went up it didn't do more damage. Nice save there.)
Amber has just a hint more red. A lot of CP/M systems from back in the day shipped with amber CRTs.
I've seen a Coco stuffed in one of these cases, but I like the idea of the original board still working, and would love to see FreHD in action. Maybe do up a Coco if you get hold of another case of this style? It would be so cool to see OS-9 running like that.
I will probably re-watch later to see if higher res that 360p is available on YT.
I see 4K. Hopefully higher than 320p 😀 What year is it? 1984? LOL
Great video ! Whilst I learned to program at school on an ICL 1904 mainframe in 1977, the first computer I actually owned was a Video Genie (aka System 80), made by EACA, a clone of the TRS-80 Model 1. I so loved that machine. Lent it out, never got it back :( We had a great TRS-80 user group for a few years too, part of a large club that catered for all the popular 8 bit machines of the day. So many happy memories!
That adhesive whatever it is that 3M makes works really well. If you ever had the double sided foam tape it just will not let go easily. You need dental floss to weaken the grip so it will come off. There may be a bit of the adhesive left behind. I know this because I had a dash camera that mounts with that stuff and it will not just pull off!
Aesthetically the Model 4 and III are two of my favourites. I would love to see a PC case with the same form. I would replace the drives with disc caddies.
That would be interesting. This screen would be fine for just about anything but high end games.
@@RetroHackShack I am very old. I remember getting excited in college when we had new amber DEC terminals with smooth scroll.
Very nice "fixup". To me, neither the "Amber" nor "Green" screen showed well on camera. Remembering amber tubes from the '80s, the color was quite saturated and rich.
On another note - most certainly use that glass screen, especially at shows - To keep the poking fingers off your display screen if nothing else!
Yes, I would like to see the FreHD and Gotek episode.
Great video and congrats on the excellent results. CRTs are awesome, but they are also cumbersome, power hungry, and becoming rare. The remaining CRTs only have to outlast Gen-Xers, since [most] Millennials aren't nostalgic about the glass monsters ;p
One more suggestion: That glass cover might be useful at conventions to keep pokey fingers off the LCD. Easier to clean, as well. Cheers!
Thanks!
YOU LET THE MAGIC SMOKE OUT!!!! Haha nice find I am new to your channel great upgrade that TRS 80 was about as nice as ive ever seen The new panel seem an awsome way to keep it going for many more years
Thanks
I got working model 3 somewhere, waiting my retirement as many other 80's pieces, someday!
Seawolf was the best game on this old platform.
Could easily incorporate the display menu buttons and the IR receiver in the black bezel.
wow, that game was really cool. especially on that machine
Great to see this project completed and you did an awesome job. We'll probably all have to do this one day when our crts all go. fyi, mine is a gate array and it's green screen, for whatever that means. i do love amber screens though so id probably be willing to use the amber mod with mine if i ever go this route.
Great video, thank you for sharing this!
Looks fantastic, can’t wait to try this on my TRS-80.
Do you know if this mod will work with the high res graphics board on the TRS80?
It should, but I don't have one to test
Yay you said height right 😆 I just finished a 3d printed OSI Superboard II “luggable” laptop.
My junior high school had TRS-80s...not sure what model. They were so horrible, no one wanted to use them so I never gained an appreciation for them but this video is awesome.
Horrible?
I was expecting a fair amount of pixel issues, thin and thick aliasing, but I guess the RPi must do some magic to anti-alias it to clean it up for the LCD.
Both my TV and computer monitor, and it just makes a massive difference to the vibrancy of the display overall, and not that you'll see on this particular build, but the colours really come out much less washed out than they do on a TFT.
TRS-80 Model II and Model III were my literal first computers at around five years old. Seeing these in action is triggering old memories of LDOS, some shooter game where you were a pyramid and had to dock between levels, and typing in long programs from various magazines.
Nice! You have a large bed 3D printer. I would like to do the same thing, but my printer (Bambu X1C) does not have a big enough bed.
And yes, I want to see all the follow-ups that you talked about.
Holy hell, the spades on the power supply, that's smart! Thanks! :)
Wow, it almost looks like a mockup, but it's totally real
I'm starting to hope that retro enthusiasts save broken tubes, the more I look into glass blowing and making vacuum tubes the more I think they're salvagable in some way, in the distant future but some retro gen-z kid in 40 years ;) "alright so after my robot cleans out the original tube, we'll be cutting the face off and replacing the phosphor, and then rebuilding the neck with a new assembly"
I'm seriously considering making room for this possibility. Just hang onto any of the ones I found broken... or um... otherwise meet their demise.
I'm trying something similar putting an LCD into a vintage monitor case. I'll need to 3d print a mount to adapt the flat LCD to the curved monitor housing which is going to be tricky. IPS is the way to go.
Good luck. You can test those bezels enough. Tricky layout.
My experience with LCD is that if you have an image but it looks crappy/ghosty, you have the dotclock inverted.
What would catch my eye is a Model III/IV case with color LCD and CoCo 3 inside.
Don't feel bad about the CRT. You aren't the first person to break one and won't be the last so this vid may help others in the future. Nearly crapped myself the first time I had one of the yellow grenades go off. 1st thing I change now - before I power-up. Would like to see the 80 character display in LSDOS or Multidos which BTW is still being developed. Definitely mount a FreHD, I use a FreHD and an HXC with my 4P, works great.
i hope you do a compaq portable 3, as i have the orange plasma, really want to upgrade to lcd with color
What kind of caps you guys use to replace those damn Rifa caps? I guess any x1 or x2 capacitor do if it has the same or better specs.
Very cool. My first computer was a TRS-80 Model 1, and I also used the Model 3 and Model 4 a lot when they came out.
My computer teacher in Junior High School had a TRS-80 Model 4 with an amber screen, a 10 Megabyte hard drive, and a graphics card. I don't know if the amber screen was stock. Knowing him it could have been something he installed.
A hole or window in the bezel would be a good place for the remote IR receiver
PCB-NO Way!
Magic smoke moment made my night.
Too bad the camera wasn't on when it first blew. You would have seen me jump!
@@RetroHackShack As a person who had many magic smoke starter jumps, I don't need a video to feel that. And I was really glad that it was an easy fix for you.
Once upon a time I had a TRS-80 Model III and it had a white phosphors CRT... I think I like the white better than the green, and (at least on TH-cam) it does look better with the glare screen on.
My dad has a TRS80 and 2 Acorn A4000s in his loft!!
Shaka, when the RIFAs blew.
what are your jumper settings for the gotek, I cannot get mine to recognize.
Bought an amber screen once… hated it, couldn’t wait to switch back to green
Call me crazy, but I always prefered flat panel over tube. Especially when it comes to text readability.
I like the filter, it could also serve to deture would-be "screen pokers" and makes it look that much more authentic.
Ok, is this manual a Radio Shack publication ? If not, who was the publisher ?
Yes. You can see the CAT number at the very beginning in the top corner I think.
Cool
Remove those velcro patches for the redundant anti-glare glass and this would be perfect. As it is with those still in place spoils the looks.
Yeah. I wanted to keep the tinted glass though.
@@RetroHackShackAgreed :)
Retro is, when even the embedded microcontroller of the lcd-interface has way more power than the computer it's put in ... and i',m not even talking about the RPi ;-)
Would like to see 80 columns in CP/M or Model 4 modes.
That's not a Gate Array board. The GA board has the floppy and RS-232 interfaces built in and doesn't use the flat, laminated cables at the top of the board. However, the GA boards came with a green screen while the non-GA boards came with white so it looks like someone replaced either the motherboard or the CRT at some point.
A bit janky, but can't argue about the appeal of a modern panel in that thing. The picture is great, and the tinted glass also seemed to work well. Surprisingly, I think I prefer the white profile. Maybe it's because it's not a CRT. The case is also quite bright.
What are pointless arrows are pointing at?
Put a CRT back in.
It's a shame the cathode ray tube tube got broken but the liquid crystal display display looks great!
The Defense Command game won't actually be doing voice synthesis, it will be playing samples. When I was a kid I was able to program sample recording and playback on my ZX Spectrum that used the same CPU and has the same 1-bit beeper sound ability as far as I'm aware. I'm no programming genius, it's actually really easy to code.
5:42 I just started watching so maybe you cover this, but it looks like you have the 128k memory upgrade there.
Thanks. I'll check it out. I was so focused on the CRT replacement I didn't check.
If you are using a RasPi then you surely need to use 'cool-retro-term' for CRT emulation with the HDMI.
Ok using actual synch and video signals vs ssh, telnet, serial etc input is something that has to be dealt with is fair.
57:56 should be playing "Paint It Black" in the background.
This is super awesome! Maybe somebody ought to make a kit.
WHY? So you too can ruin a model 4? The ONLY way this would be remotely acceptable is if the original CRT monitor was completely dead.
Oops, poor CRT, I've thought a few times about doing that to mine, as it would free up quite a bit of space in the cabinet. Just a pity that you had to go to all that HDMI carry on to get it to work, it would be nice to find an LCD that works more directly, after all that converter uses a Raspberry Pi, with WAY more computer than the whole TRS just to convert video....
Good to see a GoTech works, I've wondered about that, however I'll wait for your FreHD vid first.
One mod I did was to fit a speaker and amp inside for sound. I didn't bother putting the speaker up against any of the holes as there is so many vents at the top that it comes out load and clear as it is.
I like that speaker mod idea
So for mine, i did the speaker mod with amp and mounted the amp with volume adjustment above where the cassette jack is.. let's me do both, if i want to use the audio from the cassette cable, i can just turn down the volume on the speaker. As for the gotek, i found that after i built the trs-io which is the networked version of a frehd (i also built a regular frehd as well), i never really used the gotek and eventually just disconnected it (it was hooked up as an external drive, so no mod really). The frehd (or trsio) is the way to go, honestly, and there's a number of hd images out there with tons of the same games you'd play off disk (I'm not sure anything can't run from a hd image). I have about 5 different floppy and hd solutions and the frehd method is the only one i ever use.
Awesome! I'll look into the trs-io.
To think Apple was charging over $1K for an Apple II, a machine half as powerful, says a lot about their marketing.
Back in the '80s I had a computer called a Tandy Video Genie but I cant find this computer anywhere online, are you aware of this computer? It was labelled Tandy Video Genie and was bought from a Tandy store in England by my parents as a Christmas gift. It ran TRS-80 software on cassette.
The Video Genies I have found online are EACA TRS-80 clones.
For the bezel, matte black or carbon fibre PLA would be better as the layer lines are hidden and no sanding or filling is required.
There is literally a page on Wikipedia about it.
is that a Iomega 100MB drive in the back ground! COOL. Im into emulators.😀
OK I seen this on a few really old tandy's what is with the wrinkles in the traces I seen it before and thought I had a corroded trace
This is a method of creating PCBs that was quite common in the 70s and early 80s. That wrinkling is normal and looked like that since the board was brand new.
Awesome retro video! That screen quality does look highly excellent over the medium of YT video. Best looking text and screen quality can recall seeing being gotten out of computers of that era. That screen did very well in game play too.
@@tarstarkusz It was all reversible, but you probably didn't pay attention that he was purposely doing it in a way to where it could be reversed. Oh, and maybe he utterly despises CRTs the way I do. (Fine invention in their day - but was personally thrilled to be rid of them and I'll never have a CRT coupled to any of my retro computers.) Then there's the matter that private property is private property.
@@tarstarkuszActually, he mentioned in a chat that he accidentally broke the crt and was pretty upset about the whole thing. it was suggested he either do one of those drop in crt mods like Adrian does, or a lcd mod, and he chose to do the lcd mod. Eventually all crts will die and we'll have no choice but to install lcds in this equipment and we'll be thankful to guys like Aaron who have videos out there on ways to do it that we can use for inspiration.
@@TheSulross If you don't like CRTs, you don't belong in retrocomputing.
@@brianv2871 Yes. I didn't see that at the time I posted my comment. But it's not really "no choice" at this point. Sure, at some future date all CRTs will be dead and the equipment to refurbish them will be long gone. But that is a long ways away. There are still 1940s TVs around. New CRTs are few and far between, but they do exist and there are used ones. Monitor CRTs did not age the way early and mid CRTs aged. A few thousand hours and they looked bad. This is just not true of most 80s and 90s computer monitors. I would say the single biggest problem with monitors right now is shipping them.
@@tarstarkusz Guess I'll escort myself to the exit then (LOL!)
Back in 85 I used a TRS-80 of my college to code a Space Invaders in Pascal.
Cool
You seem to have a large format 3D printer. Why not just model the original bezel in CAD, modify it to accept the panel, and install the new screen with the original screws?
I was wondering about this myself. I'm sure time played into the route he went, but it would be interesting to see a frame that could be screwed in like the original. There's also this 3d printing mode called "fuzzy skin" that some of the 3d printing software does that would be perfect for things like this, or drive bays where it does that same type of texture as the original.
Given the trial and error fitting, I assume he just has no idea how cheap a set of digital calipers can be.
@@Pest789 Possibly, though if your printer isn't perfectly calibrated, and most aren't (unless you did all the various calibration steps), you'll start getting off the larger the print. it's always possible he was more accurate on his measurements but the printer was off... or a combination of both.
I used them plenty, but the ones I have aren't wide enough to measure this panel.
You could use the 12“ tube from Schneider GT65 monitor or every commodore PET 12“ model. they all are identical. ;)
Do these IPS screens accept a 15 KHz video signal on their VGA input?
No since it only has HDMI input. But that's where the RGBtoHDMI comes in.
@@RetroHackShack Ah, OK. I searched AliExpress and found some that have VGA inputs. Some also have DVI, others have A/V. For instance, item 1005004141169281 (YT doesn't like links)
Direct pin to pin CPU swap with better performance. Of course that was 1981ish
I'm going to make a bit of a guess here: Have you done a lot of programming in C (or a C-influenced language)? The reason I ask: on the end of line 10 of your test BASIC program, you put a semicolon (";"), which isn't needed for BASIC, but C has a semicolon after each statement. As a fellow C programmer, it's pretty much a habit to put a semicolon at the end of every line. ;)
No, that was intentional. A semicolon after a print statement suppresses the CRLF at the end of the line.
I might just be an old fart here, but I believe that the CRT is the better option,
Very cool, but those Velcro(?) tabs on each side of the monitor ruin its appearance.
Yeah. If I wasn't keeping that tinted glass I would have removed them.
RIFA and WIFA has the same problem.
FreeHD? Please, teach/show us that.
Will do!
TRS-80 Model 4!!
This is the one my younger cousins came across in an Office Demo: It turned on, but they brought it home and Destroyed it before I could ask for Possesion
Rifa capacitors... 🤢
*EDITED: Technically it's possible to construct the CRT controller "chip" with a Raspberry Pi Pico RP2040 microcontroller and DVI video converter chipset to drive embedded DisplayPort LCD panel or even a small HDMI monitor if you so desire as graphics isn't terribly intensive, as obviously it's a 8-bit computer, so you can easily get away with it. With that microcontroller, you can ditch the original video RAM altogether as it obviously got much faster RAM thereon, more than what's originally in there.