@@adriansdigitalbasement2 Which is HUGE compared to the 2x 32 Byte PROMs that contained the whole initial BOOT program in an early minicomputer I worked on.
@pgtmr2713 Yeah, I was just messin' around.😆 Forgot to add a smiley. I'm an Aussie, Australians rarely take things as seriously as we should, so long as no harm is done.😉😆👍
As an owner of this exact Samsung monitor, this was video massively informative. Mine has been a total basket case...something in the analog section went catastrophically wrong and exploded (one of the resistors quite literally burned a hole through the PCB). Never could find schematics or a manual or anything so previous attempts at repairs were stabs in the dark, and always resulted in something else smoking up. What are the odds the guts were the same as the 5154 this whole time...haha. Next time I dig it out, having the IBM schematics for reference should make things infinitely easier.
That Ironman "Super Offroad" game is an absolute blast to play on an arcade cabinet, because it uses a very unique free-spinning steering wheel control scheme. Spinning the wheel in either direction controls the rate at which your car turns, which means that once you get good at it you get to fling the wheel back and forth as you go around turns, spamming the nitro button to demolish the competition. Super fun!
I enjoy when you work on these old CRTs. This one has a particularly nice picture for its age. Very well done, Sir! You're a real CRT wizard! Cheers and all the best! 👏👏👏
The tube has almost surely been replaced! That 89 will be the date code as you suggested, and the monitor is from 87. The replacement also explains the cut ground wires on the dag ground. The original monitor the tube came from used those wires, while this monitor attaches the chassis frame to the CRT mounting tabs so there's no need for ground wires. The deflection yoke came from the other monitor along with the tube. A lot of times they are identical or close enough between wildly different monitors.
Yeah it just have been. Funny though it happened a long time ago as it was similarly dusty as everything else. I wonder what happened to require a complete swap?
@@adriansdigitalbasement2 Maybe Samsung used some awfully low resolution tube, which the owner didn't like. Or it was used in an office for some years and suffered severe screen burn. Or the original tube just failed prematurely, sometimes that happened (went to air, or a spot weld on an electrode failed, etc.).
Oh, wow! I have a Televideo 286 machine with the original Televideo branded EGA monitor. It looks identical to this Samsung, other than the Televideo logo. Makes sense, considering both were manufactured in Korea. Definitely watching this again when I go to recap it~
The "Circle and Line Symbols" were standardized in 1973. They were: ⏽for power on ⭘ for power off (both for rocker or slider switches) ⏼ for power on/off (for push switches) ⏻ for standby (soft-poweroff)
@@NielsHeusinkveld The emphasis is on being built to last. You can't just take a tank apart by removing 4 screws and neither can you take this monitor's PSU apart like that.
I have used that cleaner in the past, it works great but be careful it is flammable, so make sure it has evaporated before turning anything on. I learned the hard way (grabbing fire extinguisher).
I remember working on a number of 5154 monitors. The only thing was that they used a 'tamper resistant screw' that I had to get a bit/socket (don't remember which it was). But, the thing I only had to do with all of them was to replace a number of capacitors in the power supply. There was a third party kit that had higher temp and higher voltage caps. It was a matter of when and not if they would fail and the startup circuit would not start the power supply. Great memory!!
Very nice monitor. By the way, IBM had various OEMs for their 515x monitors. Samsung was one of them but the more common one in Europe was actually Salora, a Finnish company that became part of the Nokia group. So if you have an IBM Monitor "Made in Finland", it is a Salora/Nokia, Korea is Samsung and I think there were one or two more. My very first monitor was actually a Salora version of the 5154 (pretty sure it was a 5154, not a 5153 as my computer came with an EGA card and the monitor was able to do 640x350 in 16 and 64 color properly together with the card). The Salora actually was a perfect twin brother of the IBM with the very same case (screen slightly offset to the left with the inner bezel being a bit darker and larger on the right side, the three twist knobs for power, contrast and brightness and with the screen turning white when switching on the monitor with no signal applied, which was also common across all IBM TTL Monitors)
I wonder if anyone has shared pics of these other branded monitors? I saw inside EpicTronics European 5154 and it was definitely the same as this one. But that's just a sample size of one :-)
Ha wow, I barely got time to explore the floor so didn't see what was on offer. Well now you know you can find schematics for the IBM and mod it for 64 colors in 200 line mode :-)
Must read the datasheets of various families. 74LS input low source current IIL is 0.4mA max and maximum input low voltage is 0.8V which gives an 2KΩ maximum value of the pull down resistor (0.8/0.0004). To be safe, taking in account the long path the wire is routed in the noisy environment 1KΩ is perfect.
I got a Samsung 48" 3D TV in 2013 it still works in 2024. I have a Samitron monitor I use for my old retro Intel Xeon dual CPU build all still goes. The cost-cutting technique Samsung uses works out well in the long run. Thanks for the in-depth lesson.
Good on the folks who pointed you at the equivalent IBM branded monitor and documentation -> Turned into a bit of a windfall :) Liked seeing the EGA64 mod you implemented as well. 👍
Pointless and obscure fact: some older UK television sets were kind of multiscan to support both PAL and the older 405-line broadcasts which had a lower horizontal frequency
Good seeing you again this weekend at VCFMW. Thanks for coming all the way out here again. I hope you felt the new venue was a great improvement over the old- I know I did.
I think it was '98 or '99 and i was getting ready to build a new gaming rig. While doing some reading, i learned that a high dollar Sony monitor was the same exact monitor that KDS (Korean Data Systems) sold. And as it turns out, Sony made the picture tubes, and KDS did all the electronics. So other than the case being slightly different, it was the same monitor! And that thing was a beast! Very high resolution, and the picture was beautiful, as one would expect from a trinitron tube. This happens a lot in manufacturing, you quite often find out that it's one company (or a few) making ALL the product, and just slapping a different companies name on the outside. IIRC, there were only 3 companies making CD-rom drive mechanisms, back in the day. But there were a lot more brand names around.
This took me back. My first pc was an 8088 with a cga card. I got a second hand Hercules mono card second hand that turned out it could support ega with a couple of jumper changes. I loved ega.
I suspected that the IBM EGA monitor of the mid- to late-1980s was an IBM labeled version of this Samsung CD-1452M the moment I saw it in your video. I worked with dozens of those IBM EGA monitors back in the day. It was the second full-time job of my career, and my employer was a subsidiary of a mega-corp that had purchasing contracts (yes, that's plural) with IBM for everything from mainframes on down. The company had proprietary software that ran on every desktop, and the splash screen for that software displayed a pretty boring company logo on the CGA monitors that about half the desktops still had. But then they came out with a new version of the software whose splash screen was a photo of the main corporate campus at night. I think if a computer's display system was CGA (I don't remember there being any monochrome screens), the splash screen was still pretty boring, but if the display system was EGA or VGA, that photo appeared. The first time I saw it, I was in awe, because I'd never seen such an impressive display on a computer before. Not that anything else the company used took advantage of those EGA displays beyond somewhat better text resolution. BTW, those monitors had a serious fault. Something would spontaneously short out in there, causing the monitor to make noises and the display to go out, of course, but if left long enough, the thing would eventually catch fire. We caught several of those before seeing any flames, but not before the room was filled with acrid white smoke. I alerted my boss, who sent out a memo instructing employees to turn their monitors off when leaving at the end of the workday.
Heh yeah I figured there would be a bunch of folks who were intimately familiar with the 5154 who would recognize the guts of the Samsung monitor, connecting the lineage. And yes, turning off a monitor when away from it is always great advice. I remember when I was a kid people saying it was "better" to leave a computer and monitor on 24/7 to alleviate stress on the components from heat cycling. I thought even back then that was so silly!! Sure you might save yourself from a cracked solder joint but the wear and tear on all the parts running all the time, especially without cooling like on a Mac Plus or IIc monitor seemed not a great idea to me. Not to mention the fire risk you alluded to!
A mild aside from the monitor, but seeing Ivan Stewart's Ironman game, wow, acrade game memories there!!! I remember playing that in the 90s at an old snooker hall turned super dodgy arcade hall (the owner later turned out to be, ahem, "inappropriate" towards young people, if you get my drift!), a cabinet with three steering wheels on it for multiplayer gaming, one of those games I loved playing back then, and I think I had a version of it as "Super off road" for Amiga, but never the same as playing with a wheel attached to an arcade cabinet... :D
Before you even power these up you need to check the rubber grommets on the CRT, they turn hydroscopic and hold moisture, this will instantly destroy the scan coils, if theyre rock hard they need to be changed. Its blurred because the focus voltage is low
@@Synthematix +1 for the rubber wedges. But the picture is only blurred when the beam current is high, which is indicative of a tired tube, unfortunately. If the emissions are good, might worth trying cleaning the cathodes (NOT rejuvenating, just cathode cleaning with a few mA). Some CRT testers can do it, but I've done it in older sets which lacked beam current monitoring by just disconnecting the carhode drive and grounding the cathodes one by one until it stops sparking inside the tube.
It's basically 16 colors out of a palette of 64, this is unlike CGA which is a fixed 16 color palette. It does mean that programs that change colors can be a bit more creative with colors.
@@adriansdigitalbasement2 Years ago, I had an old DOS demo program that would display all 64 EGA colors on-screen at once, through some video timing witchcraft. It would also display all 16 CGA colors as well. I never tried it on an actual EGA card because I've never owned one. But it worked well enough on a VGA card emulating EGA.
I somewhat remember that you could alter the palette of EGA from reading about it in the past, but never realized that any software ever took advantage of it.
Thanks for yet another informative and interesting video.. and plays the reminder of the dangers of the high voltages. Back in the day I did a lot of CRT repairs and I had quite a lot of respect for the internals and always kept fingers away until I discharged things.. (and of course, keeping the things unplugged unless I was testing something that required power)
When I was in junior high, I took to messing around with the adjustment knobs inside a monochrome CGA monitor (compaq deskpro) and was able to get it to display an EGA signal, although the picture was much more narrow and squished-looking. All so I could play Wolfenstein 3D! Good times!
The strangest thing about this memory is the fact that wolfenstein3d shouldn’t have supported EGA, and yet I have a distinct memory of it working flawlessly after modifying the monitor. Perhaps the video card supported both ega and vga and was somehow sending a vga signal to the monitor? I think it may have been an Oak Technology card. Man, I wish I still had that compaq deskpro 286.
How about a PGA (Professional Graphics Adapter). EGA always had a place in my heart because it was so short lived, yet so relatively capable. PGA was supposed to be a superset of EGA running at 800x600x16. I think that would have been amazing for gaming on the lower power computers of the day, and running Desqview on 286s with enough RAM. Dream machine.
The symbol was around from before the days of '1's and '0's in everyday culture, and represents an old style toggle switch. In the 'old days', power switches were mounted through front panels or casings of appliances by a round knurled nut and had a lever to flip up or down to turn the device On or Off. THAT's what the power logo represents, nothing what so ever to do with '1's and '0's.
It's an IEC standard and the symbol varies as to how the switch controls the power state. For instance, if it's not a solid circle and the vertical line goes through the top of it, it means that it is a logic control and another component of the system controls the actual power state, bringing it in and out of a standby state and not interrupting the actual power source.
This is what Wikipedia has to say, much like @douro20 said. I still remember early red plastic rocker switches with neon lights inside arriving on the scene and the picture of a 'mains toggle switch' above them to identify its' purpose.
@@adriansdigitalbasement2 how many bit planes? In OCS and ECS, 130ns gave you the full 6 and 65ns only 4. In AGA, the full 8 were available whether 130, 65, or 37.5ns (VGA mode used the 37.5ns pixel clock).
We never had EGA. Even though we were always behind, 2-3 years maybe, if I remember correctly, because we were poor. But back in the SVGA days, we bought a 14 inch GABA CRT monitor brand new, and it could only display 800x600 pixels, and it was even advertised to do only that resolution, as the highest. And then, after 2 years of daily usage, it went dead. We took it down to the local TV service person, who fixed it. After that, it coud display 1024x768, even though the manual said it can not do that. I have no idea why.
I remember playing this game in an arcade. It swallowed up a big chunk of the money I earned every month as an apprentice. Three games did cost like 5DM (for comparison: a pack of cigarettes did cost like 3.50DM back then xD).
They probably made each version to what that particular company wanted so it was probably customized, for them, i bet the Tandy one even has something a little different in it as well. pretty cool always enjoy your videos.
I had one EGA monitor in the past, and it was a very nice Magnavox one with a colour/monochrome switch. It was in their "Professional" line. It also had an amber/green switch for the monochrome mode.
IBM invested heavily into Samsung, Tatung and Daewoo to manufacture the PS/2 displays (excluding the 8514) to support the launch of PS/2 in 1987. One of the Korean manufacturers had a significant fire at their factory, and IBM paid to have the entire factory rebuilt. I can't recall which of the three it was .. probably in 1986 but usual search engines failed
the 'yellow to red' knob controls the strength of the CGA Brown green component dimmer (Brown is transmitted as 'non-intense yellow' by a CGA card and converted by this sub-circuit).
2:00 correction, plastic *fake* grille, there are only some tiny holes at the back...why did they do these things!? [edit: wow! awesome video. I did not expect that hardware hack at the end!]
I started watching this video on bed, I thought I was going to make it butI fell asleep and I HAD A NIGHTMARE where I kept telling you "to load stuffon a Spectrum you use cassette" but you didn't believe me and kept trying to plug a floppy drive to a Spectrum, I said "I never saw anybody using floppy disks with Spectrum, everybody used cassette!" and you didn't believe me and kept doing an episode about "Fixing a Spectrum and getting it to work" hahahahahaha. In reality my school's computer room had Spectrums plugged to black and white TVs and we loaded stuff from cassette, mostly LOGO. In my dream I even told you "maybe I'm in parallell universe where Spectrum uses floppy disks? I swear in my universe it uses cassette!!!" hahahahaha :D
I've got two IBM PS/1 monitors that have Samsung tubes. And I need to look again, but they both have two horizontal adjustments. Same model that you reviewed about 3 years ago according to RUclips.
ibm 53f5798. One of the two doesn't work. Blew a cap, replaced it, smoked a POT, replaced that, and it did it again. Not sure what's wrong with it, except maybe a shorted yolk.
80s Samsung EGA monitors. Built tough and made to last. Still working and probably didn't even need that cap replaced. My recommendation though would be to use transistors or simple logic OR/NOR gate to handle the shunt to ground and use the switch to control one leg of the gate.
I think it was NEC and a few other had a monitor with tons of switches on it under a cover? Thing could do cga, ega, and vga. Had tons of connectors on the back to. The few I ran into was high hours usage and I think only did 800x600. something like that. I can't remember. Also some of them had those RGB H/V bnc connectors on the back.
Yeah those were great monitors. First came out in the late 80s like around 1989 I think. They weren't on sale long so are rare these days and truly multi sync
I actually had no issues with this particular card under Windows 98SE, and actually found it to have really quite decent performance in games from the late 90s. It was completely stable on my setup I used to test (ASUS A7V266A, Athlon XP 2000+ so similar to your one that didn't work well). It's a shame you had issues.
74xx TTL logic has built in pullups on the inputs so if you leave them floating they go high on their own (so leaving them not connected is valid desigh practice). Correspondingly, TTL outputs have high current sinking capability but low current sourcing capability, to match the characteristic of TTL inputs. For your modification, you should use a SPDT switch that switches the input between the signal or directly to ground. (common to the input pin, one throw to the color switching signal, the other throw directly to gnd). You never want to have a strong pulldown on a TTL signal as it will bring the high-output logic level out of spec.
@44:00 Monkey Island 2 and Indy 4 also support 640x200 dithered mode using the 256 color assets. Looks very nice e.g. on a 1084s, I made a little video about that. Some games such as Altered Destiny, Les Manley 1 or Darkseed I think also support 64 color palettes, albeit 350 lines for Darkseed. Plus the early Legend adventures, which run in 350 line mode, too. EDIT: it seems GODS also supported EGA64. EDIT: Ocean‘s Pushover also gets mentioned for 64 colors.
About 7:30 - A1200 does support VGA without scan doubling, but it defaults to 15.5KHz when first turned on or when playing a game. I had to use a dual monitor for mine back in the day, one was a VGA monitor connected using the RGB-out for using Workbench(it was HD installed and set to load VGA drivers before the UI appeared) and productivity at 672x576p(31KHz), and the other was a TV hooked up to the RF modulator for doing the 320x256(15.5KHz) that most games used. It could also do 800x600 and 1024x768, but those modes were unusably slow, at least on my 68030. Not sure on non-AGA systems, only ever used my A500 as a game machine hooked up to a TV. Also note: The modes I used were both 50Hz vertical refresh and the first one utilises the overscan, hence the "strange" resolutions.
Very cool feature, actually seeing the 64 colors EGA can render is a rare thing to see. Mistakes were made when 99% of EGA uses the default 16 CGA colors, such a waste of a video standard. Lol yep the lower the dot pitch value, the higher in resolution it goes, golf score rules.😉 The contrast level aspect between bright and dark colors isn't great for RGBI, with CGA colors all the second to most brightest color hues are too close to the brightest color values when forming color ramps. They did a great job with that 640x200x4bpp mode in Planet X3, would be cool to see it with the expanded EGA system palette but there just isn't enough people out there with a monitor capable of that. To see the potential of what EGA64 mode was capable of the best reference is early Amiga and VGA titles since many of them were in 4bpp global color for cross platform porting sake in that era. Well that's dumb for an EGA monitor capable of EGA64 not supporting that mode from the factory. The more I learn about CRTs the more I notice how the makers actively handicapped screens capable of much more in both SDTVs and PC monitors.😕
I don't have any EGA monitors but I'd like to mention that the RGB2HDMI works with EGA and it makes for a crazy crisp and sharp picture. TTL video is digital after all :) Just make sure your EGA card is configured to know it has an ega monitor connected (Many have dip switches to let it work with older CGA or MDA monitors and most I find are set that way) or your colors will be off in some modes.
I had a PC/XT (8MHz) bought in 1991 and had Ati EGA Wonder. I think I used it for around 2 years. There was some fun of programming those colors from GW-Basic and a bit of relief it is not CGA. After VGA I never looked back at EGA, at least until 2024 🙃
It was pretty common, before simple circuit sim software was cheap and plentiful, to design a board with trimmer pots in some positions. Later, after some empirical testing, engineers might find certain values of the trimmers work best in all cases, so later production runs will have fixed resistors in the pot location to save money.
The green wires that are cut off from the steel cables around the CRT are to facilitate ease of soldering the steel cables together. It looks like the manufacturer wrapped the cable with the copper from the wire soldered it then just cut off the excess wire. That's what it looks like to me anyways.
Are those 2 HV Caps bulging-toast? I've seen just the plastic cap bulging but worth checking. On some PSU designs, they can release semiconductor-magic-smoke when they go too far out-of-spec and bulging caps are right about there... Saw later that the picture of the IBM 5154's PSU also had those two HV caps bulging, so it's probably just the plastic cap.
I think it's just the plastic caps. For some reason, they used to do that for those high voltage primary side capacitors. I've seen that in other equipment from the same era.
Seems to be a common thing for one type of display to get branded by the computer company selling it with their computer; many of the famous Commodore monitors were also made with Acorn branding here in the UK, along with branding of system-agnostic companies like Microvitec.
I was just dorking with a Toshiba T3100 laptop's video out the other day. I couldn't get it to display a stable picture on my CRT monitor, and then it finally dawned on me: The monitor is CGA and this laptop is outputting EGA. I own several CGA-compatible CRTs, but not a single EGA one. And I don't think I've ever run across one in the wild, either.
It'd be kinda cool if there was a rotating switch between green, amber, white, regular color, and 64. And a bypass of controls for all the various adjustments... but that's probably way too much work.
Interesting, when you said the "Dk. Grey" looked correct it looked purple(ish), when you switched modes it looked blue(ish). Camera or RUclips colo(u)r reproduction causing this? BTW I had a multi-sync monitor (50/60Hz @ 15.1khz & VGA) with my Amiga A1200 and it output higher than 15.1khz without flickering. You had to set AmigaOS to use a display driver that would change the output. Which would then look like an out of sync TV signal if you used an oridinary display, like a 1084S (Yes i tried). Few games worked on it, as most up to that point did not use the OS for anything but booting to a floppy disk. They were stuck at PAL/NTSC speeds. I can't recall what resolutions over 256 pixels high where like, i think they probably did need a flicker fixer. It was fine on the lower 320x256, but i do recall running 640x256 for a while. It was vertical resolutions like 480/512 that flickered as the chipset interlaced the signal. Don't think the horizontal speed was the problem. 1280x512 was awesome even with small icons and text on a flickering screen that was a bit slower. 😍
Yep. A1200 supported VGA monitors out of the box with a simple adapter. All you had to do was use either Double-NTSC and or VGA Only drivers and workbench VGA mode was enabled. It didn't work for old games and resolutions but it was great for workbench apps and very sharp in comparison to the 1084.
Pulling up is easier than pulling down... I've had chips where a 100 Ohm pull down didn't cut it! I'd replace the jumper bridge with a resistor (4.7k would likely do the job) and make the green button short the input to the 157 to ground.
That power supply looks like a clone of the IBM 5154 ega monitors power supply. (looking at more replies, I guess this become obvious later in the video.)
When you tried VGA on the box, it looked to me that with some adjustment it would have worked. It was seeing the misshaped grid displayed when you switched to VGA, that made me think it could be.
28:07 - does a monitor of this vintage really have built-in degaussing? I've had monitors newer and more advanced than that still didn't have degaussing. When I put a small magnet up to my Sony CPD-1304 as a child, I had to put the same magnet in reverse at just the right distance to cancel out the color distortion it had caused. (My EGA monitor earlier on was actually a Samsung too, but it was the CM-4531, not this.)
Most of them had degaussing but the field strength was intended for stray magnetization, not for strongly magnetized front shadow mask from a magnet applied to the screen. External degaussing ring would remove that but it’s way stronger than the internal coil, and can be applied foe a while as needed.
I think you said that image viewer doesn't support 64 colors. Maybe there's one that does? Maybe there's one which could be modified to support it? Would be something neat for DOS users though maybe not super relevant nowadays since most people doing DOS stuff probably just go straight for VGA. Maybe Fractint supports one or both modes?
![Adrian's Digital Basement ][](http://yt3.ggpht.com/ytc/AIdro_k7CrQRe71qN6c0Ua7A1P_I8KkxjqLa70u0zYeCvdvnKw=s48-c-k-c0x00ffffff-no-rj)
53:41 Small correction: the 28L22 is a 256 byte PROM, not 256 bits.
@adriansdigitalbasement2
The term "PROM" is an oxymoron 👈
Programmable, Read, Only...
@@adriansdigitalbasement2
Which is HUGE compared to the 2x 32 Byte PROMs that contained the whole initial BOOT program in an early minicomputer I worked on.
@@snakezdewiggle6084Programmable in a programmer. Read only in the device. That's my guess as to how it could be both.
@pgtmr2713
Yeah, I was just messin' around.😆 Forgot to add a smiley.
I'm an Aussie, Australians rarely take things as seriously as we should, so long as no harm is done.😉😆👍
PROMs had burnable links, program once, read many. Once it’s burned, that’s all you get.
As an owner of this exact Samsung monitor, this was video massively informative. Mine has been a total basket case...something in the analog section went catastrophically wrong and exploded (one of the resistors quite literally burned a hole through the PCB). Never could find schematics or a manual or anything so previous attempts at repairs were stabs in the dark, and always resulted in something else smoking up. What are the odds the guts were the same as the 5154 this whole time...haha. Next time I dig it out, having the IBM schematics for reference should make things infinitely easier.
That Ironman "Super Offroad" game is an absolute blast to play on an arcade cabinet, because it uses a very unique free-spinning steering wheel control scheme. Spinning the wheel in either direction controls the rate at which your car turns, which means that once you get good at it you get to fling the wheel back and forth as you go around turns, spamming the nitro button to demolish the competition. Super fun!
I used to love playing it every time my mom would take me to the $1 movie theater.
It was a modernised off-road super sprint :) fun but rather unfair.
played the hell out that in the day
Inputs being on the left side / outputs being on the right side of blocks in schematics is a pretty soft convention. It is by no means standard.
I enjoy when you work on these old CRTs. This one has a particularly nice picture for its age. Very well done, Sir! You're a real CRT wizard! Cheers and all the best! 👏👏👏
The tube has almost surely been replaced! That 89 will be the date code as you suggested, and the monitor is from 87. The replacement also explains the cut ground wires on the dag ground. The original monitor the tube came from used those wires, while this monitor attaches the chassis frame to the CRT mounting tabs so there's no need for ground wires. The deflection yoke came from the other monitor along with the tube. A lot of times they are identical or close enough between wildly different monitors.
Yeah it just have been. Funny though it happened a long time ago as it was similarly dusty as everything else. I wonder what happened to require a complete swap?
@@adriansdigitalbasement2hey I’ve got an apple workgroup server with some issues can you help me fix it I have there very first one ever
@@adriansdigitalbasement2 Maybe Samsung used some awfully low resolution tube, which the owner didn't like. Or it was used in an office for some years and suffered severe screen burn. Or the original tube just failed prematurely, sometimes that happened (went to air, or a spot weld on an electrode failed, etc.).
@@adriansdigitalbasement2 Maybe the same thing that chewed up the plastic on the front also scratched the glass on the CRT.
What is a “rifa”?
Oh, wow! I have a Televideo 286 machine with the original Televideo branded EGA monitor. It looks identical to this Samsung, other than the Televideo logo. Makes sense, considering both were manufactured in Korea.
Definitely watching this again when I go to recap it~
Ahhh ok! So we have another company using it. Not just Tandy! Cool.
That mod was a great idea and definitely a very realistic upgrade. Great thinking!
The "Circle and Line Symbols" were standardized in 1973. They were:
⏽for power on
⭘ for power off (both for rocker or slider switches)
⏼ for power on/off (for push switches)
⏻ for standby (soft-poweroff)
Ah so that's funny they neglected to use it. I guess it wasn't mandatory.
"Removed 20 screws but we're still not done"
Yup. Built like a tank.
Aren't tanks mostly welded? :D
@@NielsHeusinkveld The emphasis is on being built to last. You can't just take a tank apart by removing 4 screws and neither can you take this monitor's PSU apart like that.
I have used that cleaner in the past, it works great but be careful it is flammable, so make sure it has evaporated before turning anything on. I learned the hard way (grabbing fire extinguisher).
I remember working on a number of 5154 monitors. The only thing was that they used a 'tamper resistant screw' that I had to get a bit/socket (don't remember which it was). But, the thing I only had to do with all of them was to replace a number of capacitors in the power supply. There was a third party kit that had higher temp and higher voltage caps. It was a matter of when and not if they would fail and the startup circuit would not start the power supply. Great memory!!
Oh, and I'm pretty sure I upset the IBM service rep when she saw my tool to open this monitor. LOL
Very nice monitor. By the way, IBM had various OEMs for their 515x monitors. Samsung was one of them but the more common one in Europe was actually Salora, a Finnish company that became part of the Nokia group. So if you have an IBM Monitor "Made in Finland", it is a Salora/Nokia, Korea is Samsung and I think there were one or two more. My very first monitor was actually a Salora version of the 5154 (pretty sure it was a 5154, not a 5153 as my computer came with an EGA card and the monitor was able to do 640x350 in 16 and 64 color properly together with the card). The Salora actually was a perfect twin brother of the IBM with the very same case (screen slightly offset to the left with the inner bezel being a bit darker and larger on the right side, the three twist knobs for power, contrast and brightness and with the screen turning white when switching on the monitor with no signal applied, which was also common across all IBM TTL Monitors)
I wonder if anyone has shared pics of these other branded monitors? I saw inside EpicTronics European 5154 and it was definitely the same as this one. But that's just a sample size of one :-)
supposedly salora/nokia made them up to 1992
I picked one of these up at VCF Midwest, but mine is branded as a TeleVideo. Very informative video!
Ha wow, I barely got time to explore the floor so didn't see what was on offer. Well now you know you can find schematics for the IBM and mod it for 64 colors in 200 line mode :-)
@@adriansdigitalbasement2 indeed! I will try that out soon! 😎
Must read the datasheets of various families.
74LS input low source current IIL is 0.4mA max and maximum input low voltage is 0.8V which gives an 2KΩ maximum value of the pull down resistor (0.8/0.0004).
To be safe, taking in account the long path the wire is routed in the noisy environment 1KΩ is perfect.
Excellent info, thanks for that!
I got a Samsung 48" 3D TV in 2013 it still works in 2024. I have a Samitron monitor I use for my old retro Intel Xeon dual CPU build all still goes. The cost-cutting technique Samsung uses works out well in the long run. Thanks for the in-depth lesson.
Wonderful as usual, loved that the mod turned out to be so easy
I love how this video developed into a deep dive into the monitor’s guts!
Good on the folks who pointed you at the equivalent IBM branded monitor and documentation -> Turned into a bit of a windfall :)
Liked seeing the EGA64 mod you implemented as well. 👍
Pointless and obscure fact: some older UK television sets were kind of multiscan to support both PAL and the older 405-line broadcasts which had a lower horizontal frequency
I remember them having a mode switch and two tuning dials. And the 405 line mode used to make an annoying high pitched squeal.
FYI, a scan of the service manual for the Tandy version is up on the Internet Archive
Oh very helpful! It would be an exact match for this then! Cool
Good seeing you again this weekend at VCFMW. Thanks for coming all the way out here again. I hope you felt the new venue was a great improvement over the old- I know I did.
I think it was '98 or '99 and i was getting ready to build a new gaming rig. While doing some reading, i learned that a high dollar Sony monitor was the same exact monitor that KDS (Korean Data Systems) sold. And as it turns out, Sony made the picture tubes, and KDS did all the electronics. So other than the case being slightly different, it was the same monitor!
And that thing was a beast! Very high resolution, and the picture was beautiful, as one would expect from a trinitron tube.
This happens a lot in manufacturing, you quite often find out that it's one company (or a few) making ALL the product, and just slapping a different companies name on the outside. IIRC, there were only 3 companies making CD-rom drive mechanisms, back in the day. But there were a lot more brand names around.
This took me back. My first pc was an 8088 with a cga card. I got a second hand Hercules mono card second hand that turned out it could support ega with a couple of jumper changes. I loved ega.
That MOD was AWESOME! 💪
That monitor is freakin awesome! No wonder it was well used.
I suspected that the IBM EGA monitor of the mid- to late-1980s was an IBM labeled version of this Samsung CD-1452M the moment I saw it in your video. I worked with dozens of those IBM EGA monitors back in the day. It was the second full-time job of my career, and my employer was a subsidiary of a mega-corp that had purchasing contracts (yes, that's plural) with IBM for everything from mainframes on down. The company had proprietary software that ran on every desktop, and the splash screen for that software displayed a pretty boring company logo on the CGA monitors that about half the desktops still had. But then they came out with a new version of the software whose splash screen was a photo of the main corporate campus at night. I think if a computer's display system was CGA (I don't remember there being any monochrome screens), the splash screen was still pretty boring, but if the display system was EGA or VGA, that photo appeared. The first time I saw it, I was in awe, because I'd never seen such an impressive display on a computer before. Not that anything else the company used took advantage of those EGA displays beyond somewhat better text resolution. BTW, those monitors had a serious fault. Something would spontaneously short out in there, causing the monitor to make noises and the display to go out, of course, but if left long enough, the thing would eventually catch fire. We caught several of those before seeing any flames, but not before the room was filled with acrid white smoke. I alerted my boss, who sent out a memo instructing employees to turn their monitors off when leaving at the end of the workday.
Heh yeah I figured there would be a bunch of folks who were intimately familiar with the 5154 who would recognize the guts of the Samsung monitor, connecting the lineage. And yes, turning off a monitor when away from it is always great advice. I remember when I was a kid people saying it was "better" to leave a computer and monitor on 24/7 to alleviate stress on the components from heat cycling. I thought even back then that was so silly!! Sure you might save yourself from a cracked solder joint but the wear and tear on all the parts running all the time, especially without cooling like on a Mac Plus or IIc monitor seemed not a great idea to me. Not to mention the fire risk you alluded to!
72 minutes of Adrian, is there anything better? 😊
Yes there is - three 14 minute episodes.
73 minutes 😂
@@tuppyglossop222 Nope.
A mild aside from the monitor, but seeing Ivan Stewart's Ironman game, wow, acrade game memories there!!! I remember playing that in the 90s at an old snooker hall turned super dodgy arcade hall (the owner later turned out to be, ahem, "inappropriate" towards young people, if you get my drift!), a cabinet with three steering wheels on it for multiplayer gaming, one of those games I loved playing back then, and I think I had a version of it as "Super off road" for Amiga, but never the same as playing with a wheel attached to an arcade cabinet... :D
Very impressive fix with the 64 color button!
That color mode switch is awesome!
Before you even power these up you need to check the rubber grommets on the CRT, they turn hydroscopic and hold moisture, this will instantly destroy the scan coils, if theyre rock hard they need to be changed.
Its blurred because the focus voltage is low
@@Synthematix +1 for the rubber wedges. But the picture is only blurred when the beam current is high, which is indicative of a tired tube, unfortunately. If the emissions are good, might worth trying cleaning the cathodes (NOT rejuvenating, just cathode cleaning with a few mA). Some CRT testers can do it, but I've done it in older sets which lacked beam current monitoring by just disconnecting the carhode drive and grounding the cathodes one by one until it stops sparking inside the tube.
@@mrnmrn1 You can also remove metallic crud from the neck by using neo magnets, sometimes theres a partial (high resistance) short
I didn't even KNOW there was a 64 color version of EGA.
It's basically 16 colors out of a palette of 64, this is unlike CGA which is a fixed 16 color palette. It does mean that programs that change colors can be a bit more creative with colors.
@@adriansdigitalbasement2 oh is that why the EA Space game "Sentinel Worlds" has an EGA palette switch option that I could never get to work?
@@adriansdigitalbasement2 Years ago, I had an old DOS demo program that would display all 64 EGA colors on-screen at once, through some video timing witchcraft. It would also display all 16 CGA colors as well. I never tried it on an actual EGA card because I've never owned one. But it worked well enough on a VGA card emulating EGA.
@@shmehfleh3115what’s the name of the demo? I want to try it in 86box
I somewhat remember that you could alter the palette of EGA from reading about it in the past, but never realized that any software ever took advantage of it.
Thanks for yet another informative and interesting video.. and plays the reminder of the dangers of the high voltages. Back in the day I did a lot of CRT repairs and I had quite a lot of respect for the internals and always kept fingers away until I discharged things.. (and of course, keeping the things unplugged unless I was testing something that required power)
When I was in junior high, I took to messing around with the adjustment knobs inside a monochrome CGA monitor (compaq deskpro) and was able to get it to display an EGA signal, although the picture was much more narrow and squished-looking. All so I could play Wolfenstein 3D! Good times!
The strangest thing about this memory is the fact that wolfenstein3d shouldn’t have supported EGA, and yet I have a distinct memory of it working flawlessly after modifying the monitor. Perhaps the video card supported both ega and vga and was somehow sending a vga signal to the monitor? I think it may have been an Oak Technology card. Man, I wish I still had that compaq deskpro 286.
How about a PGA (Professional Graphics Adapter). EGA always had a place in my heart because it was so short lived, yet so relatively capable. PGA was supposed to be a superset of EGA running at 800x600x16. I think that would have been amazing for gaming on the lower power computers of the day, and running Desqview on 286s with enough RAM. Dream machine.
The "circle with a line in it" is the symbol for power because it's a zero and a one, ie on and off
This icon was widly used for light-switches and also my old Philips-TV (from 1973) has it as powerswitch symbol
The symbol was around from before the days of '1's and '0's in everyday culture, and represents an old style toggle switch.
In the 'old days', power switches were mounted through front panels or casings of appliances by a round knurled nut and had a lever to flip up or down to turn the device On or Off.
THAT's what the power logo represents, nothing what so ever to do with '1's and '0's.
@@paulturner5769 They might be refering to power switches that have a 0 and 1 on them.
It's an IEC standard and the symbol varies as to how the switch controls the power state. For instance, if it's not a solid circle and the vertical line goes through the top of it, it means that it is a logic control and another component of the system controls the actual power state, bringing it in and out of a standby state and not interrupting the actual power source.
This is what Wikipedia has to say, much like @douro20 said.
I still remember early red plastic rocker switches with neon lights inside arriving on the scene and the picture of a 'mains toggle switch' above them to identify its' purpose.
AGA supported VGA scan rates.However the normal default video modes for entertainment software targeted lower horizontal scan rates.
Actually so did ECS, but on ECS the "productivity" mode was so slow it was kind of useless and never used.
@@adriansdigitalbasement2 how many bit planes? In OCS and ECS, 130ns gave you the full 6 and 65ns only 4. In AGA, the full 8 were available whether 130, 65, or 37.5ns (VGA mode used the 37.5ns pixel clock).
Great video, I'd love to see a followup where you do a analog VGA mod.
We never had EGA. Even though we were always behind, 2-3 years maybe, if I remember correctly, because we were poor. But back in the SVGA days, we bought a 14 inch GABA CRT monitor brand new, and it could only display 800x600 pixels, and it was even advertised to do only that resolution, as the highest. And then, after 2 years of daily usage, it went dead. We took it down to the local TV service person, who fixed it. After that, it coud display 1024x768, even though the manual said it can not do that. I have no idea why.
Maybe different parts, maybe different hz setting that time? I had a nec that could do 1024x768 only in 56hz
I remember playing this game in an arcade. It swallowed up a big chunk of the money I earned every month as an apprentice. Three games did cost like 5DM (for comparison: a pack of cigarettes did cost like 3.50DM back then xD).
They probably made each version to what that particular company wanted so it was probably customized, for them, i bet the Tandy one even has something a little different in it as well. pretty cool always enjoy your videos.
I love the MSX logo on your desk 🙃
This is great, my first PC was EGA. Ironman brings back some memories
Every time he mentioned 4077 i thought about MASH
Word of warning, that QD Electronics Cleaner doesn't lubricate at all. It's great for cleaning, but I'd buy the lubricant as well.
That is a lovely hack. Amazing deep drive into a monitor.
I had one EGA monitor in the past, and it was a very nice Magnavox one with a colour/monochrome switch. It was in their "Professional" line. It also had an amber/green switch for the monochrome mode.
What an amazing find!
IBM invested heavily into Samsung, Tatung and Daewoo to manufacture the PS/2 displays (excluding the 8514) to support the launch of PS/2 in 1987. One of the Korean manufacturers had a significant fire at their factory, and IBM paid to have the entire factory rebuilt. I can't recall which of the three it was .. probably in 1986 but usual search engines failed
the 'yellow to red' knob controls the strength of the CGA Brown green component dimmer (Brown is transmitted as 'non-intense yellow' by a CGA card and converted by this sub-circuit).
2:00 correction, plastic *fake* grille, there are only some tiny holes at the back...why did they do these things!? [edit: wow! awesome video. I did not expect that hardware hack at the end!]
I started watching this video on bed, I thought I was going to make it butI fell asleep and I HAD A NIGHTMARE where I kept telling you "to load stuffon a Spectrum you use cassette" but you didn't believe me and kept trying to plug a floppy drive to a Spectrum, I said "I never saw anybody using floppy disks with Spectrum, everybody used cassette!" and you didn't believe me and kept doing an episode about "Fixing a Spectrum and getting it to work" hahahahahaha.
In reality my school's computer room had Spectrums plugged to black and white TVs and we loaded stuff from cassette, mostly LOGO.
In my dream I even told you "maybe I'm in parallell universe where Spectrum uses floppy disks? I swear in my universe it uses cassette!!!" hahahahaha :D
I've got two IBM PS/1 monitors that have Samsung tubes. And I need to look again, but they both have two horizontal adjustments. Same model that you reviewed about 3 years ago according to RUclips.
ibm 53f5798. One of the two doesn't work. Blew a cap, replaced it, smoked a POT, replaced that, and it did it again. Not sure what's wrong with it, except maybe a shorted yolk.
Watching a video about an EGA Samsung CRT on a phone with a 1080p Samsung OLED screen makes one think about how far we have come.
80s Samsung EGA monitors. Built tough and made to last. Still working and probably didn't even need that cap replaced. My recommendation though would be to use transistors or simple logic OR/NOR gate to handle the shunt to ground and use the switch to control one leg of the gate.
I think it was NEC and a few other had a monitor with tons of switches on it under a cover? Thing could do cga, ega, and vga. Had tons of connectors on the back to. The few I ran into was high hours usage and I think only did 800x600. something like that. I can't remember. Also some of them had those RGB H/V bnc connectors on the back.
Yeah those were great monitors. First came out in the late 80s like around 1989 I think. They weren't on sale long so are rare these days and truly multi sync
What a neat little mod!
I actually had no issues with this particular card under Windows 98SE, and actually found it to have really quite decent performance in games from the late 90s. It was completely stable on my setup I used to test (ASUS A7V266A, Athlon XP 2000+ so similar to your one that didn't work well). It's a shame you had issues.
I love a good Smasnug
74xx TTL logic has built in pullups on the inputs so if you leave them floating they go high on their own (so leaving them not connected is valid desigh practice). Correspondingly, TTL outputs have high current sinking capability but low current sourcing capability, to match the characteristic of TTL inputs. For your modification, you should use a SPDT switch that switches the input between the signal or directly to ground. (common to the input pin, one throw to the color switching signal, the other throw directly to gnd). You never want to have a strong pulldown on a TTL signal as it will bring the high-output logic level out of spec.
I had an EGA monitor back in the early 90's. I wish I still had it.
CRT was replaced. I repaired hundreds of 5154s. The shield for the smps was riveted together on 5154s.
@44:00 Monkey Island 2 and Indy 4 also support 640x200 dithered mode using the 256 color assets. Looks very nice e.g. on a 1084s, I made a little video about that.
Some games such as Altered Destiny, Les Manley 1 or Darkseed I think also support 64 color palettes, albeit 350 lines for Darkseed. Plus the early Legend adventures, which run in 350 line mode, too.
EDIT: it seems GODS also supported EGA64.
EDIT: Ocean‘s Pushover also gets mentioned for 64 colors.
About 7:30 - A1200 does support VGA without scan doubling, but it defaults to 15.5KHz when first turned on or when playing a game. I had to use a dual monitor for mine back in the day, one was a VGA monitor connected using the RGB-out for using Workbench(it was HD installed and set to load VGA drivers before the UI appeared) and productivity at 672x576p(31KHz), and the other was a TV hooked up to the RF modulator for doing the 320x256(15.5KHz) that most games used.
It could also do 800x600 and 1024x768, but those modes were unusably slow, at least on my 68030. Not sure on non-AGA systems, only ever used my A500 as a game machine hooked up to a TV.
Also note: The modes I used were both 50Hz vertical refresh and the first one utilises the overscan, hence the "strange" resolutions.
Very cool feature, actually seeing the 64 colors EGA can render is a rare thing to see. Mistakes were made when 99% of EGA uses the default 16 CGA colors, such a waste of a video standard.
Lol yep the lower the dot pitch value, the higher in resolution it goes, golf score rules.😉 The contrast level aspect between bright and dark colors isn't great for RGBI, with CGA colors all the second to most brightest color hues are too close to the brightest color values when forming color ramps.
They did a great job with that 640x200x4bpp mode in Planet X3, would be cool to see it with the expanded EGA system palette but there just isn't enough people out there with a monitor capable of that. To see the potential of what EGA64 mode was capable of the best reference is early Amiga and VGA titles since many of them were in 4bpp global color for cross platform porting sake in that era.
Well that's dumb for an EGA monitor capable of EGA64 not supporting that mode from the factory. The more I learn about CRTs the more I notice how the makers actively handicapped screens capable of much more in both SDTVs and PC monitors.😕
I don't have any EGA monitors but I'd like to mention that the RGB2HDMI works with EGA and it makes for a crazy crisp and sharp picture. TTL video is digital after all :)
Just make sure your EGA card is configured to know it has an ega monitor connected (Many have dip switches to let it work with older CGA or MDA monitors and most I find are set that way) or your colors will be off in some modes.
Impresive
I had a PC/XT (8MHz) bought in 1991 and had Ati EGA Wonder. I think I used it for around 2 years. There was some fun of programming those colors from GW-Basic and a bit of relief it is not CGA. After VGA I never looked back at EGA, at least until 2024 🙃
I think I'd set the width so the circles are circles rather than to fill the screen.
It was pretty common, before simple circuit sim software was cheap and plentiful, to design a board with trimmer pots in some positions. Later, after some empirical testing, engineers might find certain values of the trimmers work best in all cases, so later production runs will have fixed resistors in the pot location to save money.
The green wires that are cut off from the steel cables around the CRT are to facilitate ease of soldering the steel cables together. It looks like the manufacturer wrapped the cable with the copper from the wire soldered it then just cut off the excess wire. That's what it looks like to me anyways.
To clean pots, I just use brake cleaner - I got some on sale for $3 a can and it works wonders.
Loved my multisync CRT
Are those 2 HV Caps bulging-toast? I've seen just the plastic cap bulging but worth checking. On some PSU designs, they can release semiconductor-magic-smoke when they go too far out-of-spec and bulging caps are right about there... Saw later that the picture of the IBM 5154's PSU also had those two HV caps bulging, so it's probably just the plastic cap.
I think it's just the plastic caps. For some reason, they used to do that for those high voltage primary side capacitors. I've seen that in other equipment from the same era.
I was more worried that they are different, I assume they are 2 of the same value in series for 110V/220V switching.
Indeed. It's just the plastic cover that does that. Pretty common from this age and it doesn't indicate an issue.
My first pc I got in the early 1990’s was a 386 16MHz with an EGA monitor.
Seems to be a common thing for one type of display to get branded by the computer company selling it with their computer; many of the famous Commodore monitors were also made with Acorn branding here in the UK, along with branding of system-agnostic companies like Microvitec.
Houdini works well for cleaning potentiometers. It cleans and lubricates. Just don't get it around polystyrene plastic as it will dissolve it.
I was just dorking with a Toshiba T3100 laptop's video out the other day. I couldn't get it to display a stable picture on my CRT monitor, and then it finally dawned on me: The monitor is CGA and this laptop is outputting EGA. I own several CGA-compatible CRTs, but not a single EGA one. And I don't think I've ever run across one in the wild, either.
Nice monitor, Adrian :)
But if you want something cool, get a Sony Trinitron 1080i, from 1989.
It'd be kinda cool if there was a rotating switch between green, amber, white, regular color, and 64. And a bypass of controls for all the various adjustments... but that's probably way too much work.
Nice! Score on finding that
I miss CompuShow. Good times.
Those plastic pieces are actually to help eliminate coil buzz on the transformer, not structural I believe
Interesting, when you said the "Dk. Grey" looked correct it looked purple(ish), when you switched modes it looked blue(ish). Camera or RUclips colo(u)r reproduction causing this?
BTW I had a multi-sync monitor (50/60Hz @ 15.1khz & VGA) with my Amiga A1200 and it output higher than 15.1khz without flickering. You had to set AmigaOS to use a display driver that would change the output. Which would then look like an out of sync TV signal if you used an oridinary display, like a 1084S (Yes i tried). Few games worked on it, as most up to that point did not use the OS for anything but booting to a floppy disk. They were stuck at PAL/NTSC speeds. I can't recall what resolutions over 256 pixels high where like, i think they probably did need a flicker fixer. It was fine on the lower 320x256, but i do recall running 640x256 for a while. It was vertical resolutions like 480/512 that flickered as the chipset interlaced the signal. Don't think the horizontal speed was the problem.
1280x512 was awesome even with small icons and text on a flickering screen that was a bit slower. 😍
Yep. A1200 supported VGA monitors out of the box with a simple adapter. All you had to do was use either Double-NTSC and or VGA Only drivers and workbench VGA mode was enabled. It didn't work for old games and resolutions but it was great for workbench apps and very sharp in comparison to the 1084.
@@RacerX- I discovered Dune II worked. Properly coded stuff just keeps going. 🙂
@@techkev140 Nice! I will have to try that as I think I still have my Dune II originals for Amiga.
Soft Scrub is pretty good as a mildly abrasive cleaner. Or course baking powder and water is also pretty good, for the same reason.
Pulling up is easier than pulling down... I've had chips where a 100 Ohm pull down didn't cut it!
I'd replace the jumper bridge with a resistor (4.7k would likely do the job) and make the green button short the input to the 157 to ground.
I once had a rifa capacitor pop in my ebay apple iigs computer a few years ago. It was a bit of a surprise and a concern. Stunk up my room for a day.
That power supply looks like a clone of the IBM 5154 ega monitors power supply. (looking at more replies, I guess this become obvious later in the video.)
When you tried VGA on the box, it looked to me that with some adjustment it would have worked. It was seeing the misshaped grid displayed when you switched to VGA, that made me think it could be.
28:07 - does a monitor of this vintage really have built-in degaussing? I've had monitors newer and more advanced than that still didn't have degaussing. When I put a small magnet up to my Sony CPD-1304 as a child, I had to put the same magnet in reverse at just the right distance to cancel out the color distortion it had caused.
(My EGA monitor earlier on was actually a Samsung too, but it was the CM-4531, not this.)
Most of them had degaussing but the field strength was intended for stray magnetization, not for strongly magnetized front shadow mask from a magnet applied to the screen. External degaussing ring would remove that but it’s way stronger than the internal coil, and can be applied foe a while as needed.
04:33 - ADRIBO!
u are awsome
And now this monitor will become IMPOSSIBLE to get your hands on.. that's ok though..
Amiga held on to that weird low refresh rates for far too long. They should’ve took a leaf out of Acorns book.
isn't the current power button just a ONE and ZERO combined for on and off
I think you said that image viewer doesn't support 64 colors. Maybe there's one that does? Maybe there's one which could be modified to support it? Would be something neat for DOS users though maybe not super relevant nowadays since most people doing DOS stuff probably just go straight for VGA. Maybe Fractint supports one or both modes?
Compushow seems to use the color palette properly. It's 16 colors out of 64 on EGA.
1kΩ is customary as a pull down resistor on TTL LS series, 10k won't work because of the internal circuitry.
I'm sorry, but the SAMS schematic is correct, there is no indication on whether ping 4 is an input or output.
Great video !