Just wanted to drop you a line and let you know I just built this board (had PCBWay print version 0.10.1) and it works great! I have it connected to an OSSC (not a GBS-8200) and it has no issues at all. So far I've hooked a Tandy 1000 EX up to it, and I'm going to try out a Laser 128 (with RGB adapter) and a C128DCR later too. Although I have a couple RGB monitors kicking around, they're for dedicated computer setups, so it's nice to finally be able to work on CGA/digital RGB computers on my OSSC/HDMI workbench without having to disconnect a monitor and lug it around. Thanks for making the design open source!
This stuff's a bit over my head, but I always thought I was using mine for a CGA type signal. I use the GBS with Roland samplers which output RGB as TTL signals along with the two sync lines (15k horizontal). Decades ago, I used the same outputs to feed a standard Tandy CGA monitor with no issues. BTW- I never did understand why these things have a 15 pin sub for input when they're supposed to be for CGA,etc. -Thanks for the videos too!
Hi, very nice project. Trying for my old computer with broken LCD screen. All the info in the project usefull for me. Hope will work. Thnks for sharing.
Honestly, you don’t know what you are missing! It makes an amazing scaler with GBS-Control installed. Nothing compares until you get to 5x the price (OSSC territory).
Hi my friend! I am waiting for the follow-up :) . In the past I was thinking to buy one to connect to my Amigas, but many people reported that the picture quality is very poor. There are some web pages that show how to mod the GBS to get a very good image quality. If I remember correctly, one of the first things to do is to replace those crappy caps with some new ones and different capacitance. I could be an nice idea to some more follow-up videos... Enhancing the output quality of the GBS...
Hi Jorge! Thank you once again :D I was on this topic for quite a long time yet and learned a lot of stuff about video formats and also gbs-8200. I tried couple of things, also capacitors and better shielding, but the best and simplest way to improve the quality dramatically is just to replace the firmware with gbs-control. It's open source and you can find it on github. I think I will tell couple of words about it in the next video, but you already can find a lot of videos on it and the follow up will be more about my adapter, which I briefly showed in the end. Anyway, the image with gbs-control is extremely good.
Hello, Great project, I will need and try this soon. May I suggest a improvement?: Put all (most) traces in bottom (non component) side. this way you can still make the PCB at home, sort of one sided. A couple of soldered wires aren't a big deal, but etching a 2-sider is.
Hi!! cool video, do you know if a replacement for the GAL16V8B (ATF16V8B/BQL and ATF16V8C/CZ.) could work ? its harder to get a GAL without purchasing it from china and wait 2 months to continue the buil. Regards and thank you for your great videos
I’ve been using one for years. Originally got it for my arcade boards but I installed GBS-Control years ago to make it a general purpose scaler. You should seriously look into it because it makes this an amazing device! Maybe you’ve noticed, but people often used VGA to refer to resolution… like 640x480p. In other words, it doesn’t always refer to an output specification. I always assumed they use CGA/EGA to mean 240p resolutions in a similar way.
I looked quite seriously into it, just watch the follow up videos to see, how it went. In regards of EGA/VGA/CGA, what people say is one thing and what you write into the specs is another. You can't just write, that your device supports digital video formats, but do analogue only. If they call it so only because the resolution or frequency, than I can call bicycle a car because it has wheels ;)
@@necro_ware I agree, but it’s not worth arguing that a “VGA” webcam that plugs into USB isn’t VGA. In the case of EGA/CGA people aren’t rampantly abusing the terminology yet so there is still a chance to save it. ;)
@@emmettturner9452 Well, I don't know how about you, but if I buy a device, which primary job is to convert particular video signals, and which advertises it, but doesn't do that, I feel slightly scammed. It's like to pay for a mouse and to get a joystick instead with an explanation, that everything is USB after all :D
@@necro_ware Yep. Pretty big fail on their part. Back then I assumed that arcade guru’s were just weird and adopted CGA/EGA as shorthand for those resolutions, though I was already aware that they were calling things medium res, high res, etc when they were all SD resolutions.
@@emmettturner9452 That is actually even more complicated, since there are two EGA modes and they couldn't be more different. The one is a low-res, but is pretty much CGA otherwise. It just had more memory and could use 16 colors, instead of pallets of 4 colors as with CGA. But everything else was the same and you could even use CGA monitors with low-res EGA. An then there is the high-res EGA which is completely different with RGBIrIgIb signal with up to 64 colors, almost double the resolution and completely incompatible inverted sync at 21kHz instead of 15kHz, which were used for CGA and low-res EGA. But GBS-8200 manufacturer didn't bother about that minor details, they just printed CGA/EGA on it and ciao. I was really confused, as I started to evaluate it. However, on the good side, that pushed me do investigate deeper and to make my MCE-Adapter. So, even if I don't appreciate such a scam, I'm still happy :D
Nice ! I've seen that thing being used previously by other people in use for SCART capturing or just displaying consoles's signal on a VGA monitor, but I've always been wondering if that statement about CGA/EGA was correct ... I guess it wasn't x)
Hi Deksor! Nice to see you here again :D Yes, that CGA/EGA statement was just a lie, but this way I found my way to a very interesting project and learned a lot of stuff... more on this is coming soon.
@@necro_ware nice to se YOU again here :) By the way I just ordered a raspberry pi zero to hdmi thingy. It will be great for me to capture old signals ^^. I saw you learned about this in another comment.
Came across your video. I have an old 8-liner machine. Cherry master. Wanted to replace the old CGA/CRT monitor with A LCD. Bought that “converter “ and no signal. Do you know what I can buy so I can use it? Thank you
@@RenManinJapan Unfortunately, this is all I have on this topic. The converter doesn't understand CGA/EGA and you have to convert that signal in RGBS, as I showed it in the video. No other way if you want to use GBS-8200. However, meanwhile there is also cga2hdmi adapter available, which is built around raspberry pi. You can toss the GBS-8200 completely and try that instead.
Shame you had to learn it the hard way! :( But yes, sadly the terms "CGA" and "EGA" are misused in the arcade board industry+hobby, as shorthand for any 15kHz and 21kHz video signal respectively. As you point out, the GBS was originally intended for the arcade market, so it makes some sense why they used those designators, despite contemporary arcade video being almost exclusively analogue RGB+S.
No need for sorrow, I learned quite a bit as I dived into it. Furthermore it ended in my MCE Adapter, which already was helpful for many tinkerers around the world :)
I've only ever seen people say 15K or 24K when talking about arcades. Never heard anyone use CGA or EGA. Maybe it's more common among the older pre-JAMMA crowd?
That is not entirely right. There was an analog CGI signal indeed designed for NTSC, but was specified for a composite output. The so called RGBI was specified only for TTL.
So the main purpose of GBS-8200, why it was made in the first place, was old arcade machines? This board helps to replace arcade monitors with a new VGA ones? Still don't know why it's so widely available, CGA/EGA converters are in demand too, and they could be made as cheap as this.
Yes, mainly yes. It works for the cabinets, but also Amiga and some other computers. However, it does not, what it is proudly advertising - support for CGA and EGA. Anyway, in the next part I will show how to close this gap.
@@necro_ware: Perhaps I am giving too much credit, but is it possible they got confused? VGA is backwards compatible with EGA and CGA, and perhaps that's what they were thinking. However, I'm doubtful of this theory, as I would assume that if they advertise CGA and EGA compatibility, then they must have tested it for that compatibility; clearly, they did not.
@@Christopher-N They probably use EGA/CGA to refer to those resolutions and not to their actual video standards… much like picking those resolutions in an old PC game with a VGA graphics card installed.
I was curious if the gbs could actually convert legit cga/ega signals. The arcade community isnt always the most tech minded and when ive asked collectors if their monitor does 15/24/31khz they just get confused until I mentioned cga, ega, or vga, and then they of course understand 😂. So yeah, blame the arcade crowd for the improper naming.
Yes, but you need a resistor on the composite sync signal, since the voltage from the Amiga is too high for the GBS. See: ruclips.net/video/q3J4QJsn0ig/видео.html ruclips.net/video/xqlrOcGZx38/видео.html
I tried the GBS-8200 on my Amiga and the tearing, shearing and latency were so terrible I couldn't take it. I ended up building my own S-Video converter using an AD725.
I will briefly talk about it in the next video, but if you use gbs-control firmware, the image quality is mind blowing and the latency falls by far under 20ms. Even if GBS-8200 is a lie in regards of CGA/EGA, it is still a very interesting device for tinkerers among us. Unfortunately, the firmware is obviously a pile of crap and thanks to gbs-control the device shows the full potential of the hardware. It's pretty amazing, believe me....
@@necro_ware Good point. Have you seen the Raspberry Pi Zero implementation that has very low latency and proving to be really good solution for many platforms?
@@necro_ware that doesnt answer the question... you could have put a female vga on the gbs side and plug straight in...then plug your ega cable into the other end... SMH
@@WacKEDmaN This is what I do, when I need to connect it to GBS. I put female adapter in between, but in 99% I use my monitor, where I don't need any adapter.
Another solution is to use a european TV set with good old Peritel (or SCART) input. Another plus of using a TV set is using CGA graphics card with composite output, and enjoy 16 color graphics instead of awfull 4 color graphics mode
Yes, they do, because Amiga luckily puts 15kHz analogue RGBS on the output. It's those EGA/CGA inscriptions, which are so irritating, since this device doesn't understand that standards.
Those pins in the white port are connected to that DB-15 port pins, so they are the same. And the DB-15 port looks like VGA, but it isn't. It is analog RGBS with composite 15kHz signaling. VGA is RGBHV at 31kHz.
Well you actually have to connect the two sync signals, but you can't just twist the two cables. It is not very complicated, but also not that simple. Anyway, it is not only about the sync, also the RGB color information is in a completely different format. As I explained, GBS-8200 wants analog RGB signal, where every color is mixed out of RGB values each between 0..5V, so this allows to produce nearly unlimited amount of colors (well with 24 bit and 8 bit per channel, you can reach 16,7M colors), but CGA/EGA has only digital RGB color values 0 and 1, nothing in between. That means, that you can get maximum of 8 colors. What I didn't tell in this video (there was just a remark), that CGA/EGA both have additional color intensity information, which is not part of RGBS. So, in short, if you even will manage the problem with the composite sync and try to connect CGA/EGA, you will get wrong colors. So, no, the problem is not only the sync signal. But stay tuned for the next part ;)
@@necro_ware Thanks! Looking forward to the next part. Yes, I understood the difference, but in the end digital just means there's no in between once in the analog domain. It's 0% or 100%. But I didn't know there was intensity being carried in CGA/EGA. In which case it makes lots of sense an adapter a little more complex is needed.
@@jeremiefaucher-goulet3365 I guess, you confuse it with S-Video/Composite. EGA, CGA and Hercules have so called Intensity signal, which doubles the amount of colors.
Looking forward to the follow up, I have also tried to build adapters for my GBS8200, so far I was only lucky with CGA, not EGA. Was using that video as reference ruclips.net/video/vwKA1z8tg1g/видео.html So I'm very excited for your solution. My EPROM solution for the EGA adapter produces a very dark picture and not sharp corners, I think that has something to do with my EPROM which has 200ns access time (probably too slow)... Currently waiting for some faster EEPROMs...
Yes, the very same video was an inspiration for me, but I have a completely different solution. The problem with the solution from TheRastery is the EEPROM latency indeed. Please stay tuned, more info is coming up :)
No, you wrong!! :)) CGA and EGA have analogue RGB, but it have only full ON or full OFF - no gray state. A was have EGA monitor and with a little change in schematic it became common RGB monitor. So, you just plug RGB directly to converter or thru resist divider(5V to 1V) To merge sync signal you can use resistor and diod and invertor, if it need :)
@@necro_ware No, digital have some bits became to different colors, but in this case it only on/off current line - I think it's "binary output", becouse of two state, not digital)) I'm forgot about intensity - but it just add brightness to channel, so you can use resistors plus diode from intensity to make truly analogue RGB :))
I really don't want to argue about this, but MDA/CGA/EGA standards are officially called "digital TTL". If you are really curious, I think Wikipedia is a good start: en.wikipedia.org/wiki/Color_Graphics_Adapter. Digital means, that you have 0 or 1 (0V or 5V) and, that the system can't take any values in between. The thing, where multiple bits are encoding an information, like color, are called protocol and is more advanced digital technology. MDA/CGA/EGA were no so advanced, but still a simple 1-bit digital format. VGA introduced so called RAMDAC, which was responsible to translate digital to analogue signal to provide it to an analogue VGA monitor. So, it is funny, but our first PC monitors were digital until we got analogue with VGA and eventually digital again with DVI and later. You are right in regards of connecting a digital CGA/EGA to analogue RGB. It will accidentally work, because analogue RGB will try to interpret digital signals and will even get a picture, but your colors will be extremely bright, the number would be reduced to 8 and would look wrong. Furthermore, you would damage GBS-8200 over longer period of time, because it is not designed to constantly hold up 5V on the input.
@@necro_ware I think IBM engineers was "Hi", then they invent CGA/EGA output, or they try to prevent use standard TV with IBM, because it use common TV frequencies - very weird "improvement")) Same graphic genererator use ZX Spectrum, but it standard RGB+HV output
Yes, because Jamma is not CGA/EGA, but analog RGBS. This is what I wanted to point out. If you look on the PCB of GBS-8200 you will see "CGA/EGA/YUV to VGA" and this is a lie.
Also disappointed with these Gonbas GBS8200s, that garbage doesn't work either, on my old Dialog4 Deckel FP2NC. Why advertise it as CGA/EGA converter, if it doesn't work???
I've heard people sourcing components through AliExpress. Based on what I've read about that retailer, and who owns what, I'm not yet ready to trust. Perhaps it works for some buyers, but I don't feel there's enough oversight yet, and the outside world does not entirely trust China itself because of the behavior of its government. Not disparaging the Chinese people at all, who are usually caring and industrious.
In regards of politics, I don't trust any government, they all do very cruel things and sell it as a necessity or charity (depends) to their own nations. China, USA, Russia, EU - for me they all are equally bad guys, however the last one seems not have to much to say in the international politics :) Once it is clear, you will stand in front of the question, if you want to buy anything at all, because once you do, you support one of them. So, if you decide to buy things, it doesn't matter where they are from. And back to topic, GBS-8200 was made and is sold from China only. Everything you can buy in your country is imported from there. If you exclude the reseller in the middle and buy it directly from China, you'll just get it cheaper, but it will be the same product, which will not work with EGA and CGA :)
i think the problem with Chinese sellers is they put extra search terms in the listing that are similar but simply NOT technically correct, so its partly to get hits on a search, and partly the seller does a wide variety of goods but doesnt have the technical knowledge to identify technology components. even if a tech manufacturer copies a product, some dont have proper engineering understanding.
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![Natanael Cano x Oscar Maydon - Giza [Official Video]](http://i.ytimg.com/vi/eXCS6-MSQ_Y/mqdefault.jpg)
Just wanted to drop you a line and let you know I just built this board (had PCBWay print version 0.10.1) and it works great! I have it connected to an OSSC (not a GBS-8200) and it has no issues at all. So far I've hooked a Tandy 1000 EX up to it, and I'm going to try out a Laser 128 (with RGB adapter) and a C128DCR later too. Although I have a couple RGB monitors kicking around, they're for dedicated computer setups, so it's nice to finally be able to work on CGA/digital RGB computers on my OSSC/HDMI workbench without having to disconnect a monitor and lug it around. Thanks for making the design open source!
Good information and waiting for the next parts of your adapter. THX for sharing and big thumbs up for you as usual. 👍🏻👍🏻
Thank you very much!
This stuff's a bit over my head, but I always thought I was using mine for a CGA type signal. I use the GBS with Roland samplers which output RGB as TTL signals along with the two sync lines (15k horizontal). Decades ago, I used the same outputs to feed a standard Tandy CGA monitor with no issues. BTW- I never did understand why these things have a 15 pin sub for input when they're supposed to be for CGA,etc. -Thanks for the videos too!
Hi, very nice project. Trying for my old computer with broken LCD screen. All the info in the project usefull for me. Hope will work. Thnks for sharing.
Thank you your video was very helpful
This was really useful, I was looking at this adapter several times and almost bought it, now I know I was lucky not to :D
Honestly, you don’t know what you are missing! It makes an amazing scaler with GBS-Control installed. Nothing compares until you get to 5x the price (OSSC territory).
Hi my friend! I am waiting for the follow-up :) . In the past I was thinking to buy one to connect to my Amigas, but many people reported that the picture quality is very poor. There are some web pages that show how to mod the GBS to get a very good image quality. If I remember correctly, one of the first things to do is to replace those crappy caps with some new ones and different capacitance. I could be an nice idea to some more follow-up videos... Enhancing the output quality of the GBS...
Hi Jorge! Thank you once again :D I was on this topic for quite a long time yet and learned a lot of stuff about video formats and also gbs-8200. I tried couple of things, also capacitors and better shielding, but the best and simplest way to improve the quality dramatically is just to replace the firmware with gbs-control. It's open source and you can find it on github. I think I will tell couple of words about it in the next video, but you already can find a lot of videos on it and the follow up will be more about my adapter, which I briefly showed in the end. Anyway, the image with gbs-control is extremely good.
Hello, Great project, I will need and try this soon. May I suggest a improvement?: Put all (most) traces in bottom (non component) side. this way you can still make the PCB at home, sort of one sided. A couple of soldered wires aren't a big deal, but etching a 2-sider is.
Thanks! They are mostly on one side, only power traces are on the back and those can be replaced with a wire.
Hi!! cool video, do you know if a replacement for the GAL16V8B (ATF16V8B/BQL and ATF16V8C/CZ.) could work ? its harder to get a GAL without purchasing it from china and wait 2 months to continue the buil. Regards and thank you for your great videos
Hi, thank you! You can take any GAL model, which has built-in pull-up resistors on the input pins. I use ATF16V8B too.
I’ve been using one for years. Originally got it for my arcade boards but I installed GBS-Control years ago to make it a general purpose scaler. You should seriously look into it because it makes this an amazing device! Maybe you’ve noticed, but people often used VGA to refer to resolution… like 640x480p. In other words, it doesn’t always refer to an output specification. I always assumed they use CGA/EGA to mean 240p resolutions in a similar way.
I looked quite seriously into it, just watch the follow up videos to see, how it went. In regards of EGA/VGA/CGA, what people say is one thing and what you write into the specs is another. You can't just write, that your device supports digital video formats, but do analogue only. If they call it so only because the resolution or frequency, than I can call bicycle a car because it has wheels ;)
@@necro_ware I agree, but it’s not worth arguing that a “VGA” webcam that plugs into USB isn’t VGA. In the case of EGA/CGA people aren’t rampantly abusing the terminology yet so there is still a chance to save it. ;)
@@emmettturner9452 Well, I don't know how about you, but if I buy a device, which primary job is to convert particular video signals, and which advertises it, but doesn't do that, I feel slightly scammed.
It's like to pay for a mouse and to get a joystick instead with an explanation, that everything is USB after all :D
@@necro_ware Yep. Pretty big fail on their part. Back then I assumed that arcade guru’s were just weird and adopted CGA/EGA as shorthand for those resolutions, though I was already aware that they were calling things medium res, high res, etc when they were all SD resolutions.
@@emmettturner9452 That is actually even more complicated, since there are two EGA modes and they couldn't be more different. The one is a low-res, but is pretty much CGA otherwise. It just had more memory and could use 16 colors, instead of pallets of 4 colors as with CGA. But everything else was the same and you could even use CGA monitors with low-res EGA. An then there is the high-res EGA which is completely different with RGBIrIgIb signal with up to 64 colors, almost double the resolution and completely incompatible inverted sync at 21kHz instead of 15kHz, which were used for CGA and low-res EGA.
But GBS-8200 manufacturer didn't bother about that minor details, they just printed CGA/EGA on it and ciao. I was really confused, as I started to evaluate it. However, on the good side, that pushed me do investigate deeper and to make my MCE-Adapter. So, even if I don't appreciate such a scam, I'm still happy :D
Nice ! I've seen that thing being used previously by other people in use for SCART capturing or just displaying consoles's signal on a VGA monitor, but I've always been wondering if that statement about CGA/EGA was correct ... I guess it wasn't x)
Hi Deksor! Nice to see you here again :D Yes, that CGA/EGA statement was just a lie, but this way I found my way to a very interesting project and learned a lot of stuff... more on this is coming soon.
@@necro_ware nice to se YOU again here :)
By the way I just ordered a raspberry pi zero to hdmi thingy. It will be great for me to capture old signals ^^. I saw you learned about this in another comment.
Came across your video. I have an old 8-liner machine. Cherry master. Wanted to replace the old CGA/CRT monitor with A LCD. Bought that “converter “ and no signal. Do you know what I can buy so I can use it?
Thank you
This is the first part of this video.
@@necro_ware I watched them all. But differences in what I need.
@@RenManinJapan Unfortunately, this is all I have on this topic. The converter doesn't understand CGA/EGA and you have to convert that signal in RGBS, as I showed it in the video. No other way if you want to use GBS-8200. However, meanwhile there is also cga2hdmi adapter available, which is built around raspberry pi. You can toss the GBS-8200 completely and try that instead.
nice
Shame you had to learn it the hard way! :( But yes, sadly the terms "CGA" and "EGA" are misused in the arcade board industry+hobby, as shorthand for any 15kHz and 21kHz video signal respectively. As you point out, the GBS was originally intended for the arcade market, so it makes some sense why they used those designators, despite contemporary arcade video being almost exclusively analogue RGB+S.
No need for sorrow, I learned quite a bit as I dived into it. Furthermore it ended in my MCE Adapter, which already was helpful for many tinkerers around the world :)
I've only ever seen people say 15K or 24K when talking about arcades. Never heard anyone use CGA or EGA. Maybe it's more common among the older pre-JAMMA crowd?
Nice
CGA/EGA can be TTL-level digital or analog signal.İt's depends the platform.
Analog one generally called RGBI.
That is not entirely right. There was an analog CGI signal indeed designed for NTSC, but was specified for a composite output. The so called RGBI was specified only for TTL.
So the main purpose of GBS-8200, why it was made in the first place, was old arcade machines? This board helps to replace arcade monitors with a new VGA ones?
Still don't know why it's so widely available, CGA/EGA converters are in demand too, and they could be made as cheap as this.
Yes, mainly yes. It works for the cabinets, but also Amiga and some other computers. However, it does not, what it is proudly advertising - support for CGA and EGA. Anyway, in the next part I will show how to close this gap.
@@necro_ware: Perhaps I am giving too much credit, but is it possible they got confused? VGA is backwards compatible with EGA and CGA, and perhaps that's what they were thinking. However, I'm doubtful of this theory, as I would assume that if they advertise CGA and EGA compatibility, then they must have tested it for that compatibility; clearly, they did not.
@@Christopher-N They probably use EGA/CGA to refer to those resolutions and not to their actual video standards… much like picking those resolutions in an old PC game with a VGA graphics card installed.
I was curious if the gbs could actually convert legit cga/ega signals. The arcade community isnt always the most tech minded and when ive asked collectors if their monitor does 15/24/31khz they just get confused until I mentioned cga, ega, or vga, and then they of course understand 😂. So yeah, blame the arcade crowd for the improper naming.
BTW what does that SW button on the board do ?
www.mikesarcade.com/estore/datasheets/GBS-8200-booklet.pdf
Wait, so the GBS-8200 is useful as is for Amiga owners? Just need to fashion a cable?
Yes, but you need a resistor on the composite sync signal, since the voltage from the Amiga is too high for the GBS.
See:
ruclips.net/video/q3J4QJsn0ig/видео.html
ruclips.net/video/xqlrOcGZx38/видео.html
@@necro_ware super! Thanks
I tried the GBS-8200 on my Amiga and the tearing, shearing and latency were so terrible I couldn't take it. I ended up building my own S-Video converter using an AD725.
I will briefly talk about it in the next video, but if you use gbs-control firmware, the image quality is mind blowing and the latency falls by far under 20ms. Even if GBS-8200 is a lie in regards of CGA/EGA, it is still a very interesting device for tinkerers among us. Unfortunately, the firmware is obviously a pile of crap and thanks to gbs-control the device shows the full potential of the hardware. It's pretty amazing, believe me....
@@necro_ware Good point. Have you seen the Raspberry Pi Zero implementation that has very low latency and proving to be really good solution for many platforms?
@@cbmeeks Yes, the one just came shortly, right?
why didnt u make the adapter with a female connector so ya could just plug it into the GBS without another cable inbetween?
Because I use it mostly with a VGA cable of my monitor, which can handle the low frequencies
@@necro_ware that doesnt answer the question... you could have put a female vga on the gbs side and plug straight in...then plug your ega cable into the other end... SMH
@@WacKEDmaN This is what I do, when I need to connect it to GBS. I put female adapter in between, but in 99% I use my monitor, where I don't need any adapter.
Another solution is to use a european TV set with good old Peritel (or SCART) input. Another plus of using a TV set is using CGA graphics card with composite output, and enjoy 16 color graphics instead of awfull 4 color graphics mode
They work GREAT On Amigas!
Yes, they do, because Amiga luckily puts 15kHz analogue RGBS on the output. It's those EGA/CGA inscriptions, which are so irritating, since this device doesn't understand that standards.
I always thought cga/ega was only through the white connection to the left of the vga port.
Those pins in the white port are connected to that DB-15 port pins, so they are the same. And the DB-15 port looks like VGA, but it isn't. It is analog RGBS with composite 15kHz signaling. VGA is RGBHV at 31kHz.
@@necro_ware yeah i seen a close up of the silk screen those far left pins claim to be the rgbs connection.
Unless I'm mistaken, the only issue is the sync signals being seperated.
I guess it isn't as simple as connecting together the two sync signals? ;)
Well you actually have to connect the two sync signals, but you can't just twist the two cables. It is not very complicated, but also not that simple. Anyway, it is not only about the sync, also the RGB color information is in a completely different format. As I explained, GBS-8200 wants analog RGB signal, where every color is mixed out of RGB values each between 0..5V, so this allows to produce nearly unlimited amount of colors (well with 24 bit and 8 bit per channel, you can reach 16,7M colors), but CGA/EGA has only digital RGB color values 0 and 1, nothing in between. That means, that you can get maximum of 8 colors. What I didn't tell in this video (there was just a remark), that CGA/EGA both have additional color intensity information, which is not part of RGBS. So, in short, if you even will manage the problem with the composite sync and try to connect CGA/EGA, you will get wrong colors. So, no, the problem is not only the sync signal. But stay tuned for the next part ;)
@@necro_ware Thanks! Looking forward to the next part.
Yes, I understood the difference, but in the end digital just means there's no in between once in the analog domain. It's 0% or 100%. But I didn't know there was intensity being carried in CGA/EGA. In which case it makes lots of sense an adapter a little more complex is needed.
Oh I just realized... You probably meant luma. Duh
@@jeremiefaucher-goulet3365 I guess, you confuse it with S-Video/Composite. EGA, CGA and Hercules have so called Intensity signal, which doubles the amount of colors.
@@necro_ware Right! Thanks for reminding me of this doubling
Looking forward to the follow up, I have also tried to build adapters for my GBS8200, so far I was only lucky with CGA, not EGA. Was using that video as reference ruclips.net/video/vwKA1z8tg1g/видео.html So I'm very excited for your solution. My EPROM solution for the EGA adapter produces a very dark picture and not sharp corners, I think that has something to do with my EPROM which has 200ns access time (probably too slow)... Currently waiting for some faster EEPROMs...
Yes, the very same video was an inspiration for me, but I have a completely different solution. The problem with the solution from TheRastery is the EEPROM latency indeed. Please stay tuned, more info is coming up :)
@@necro_ware oh wow, now I'm, even more excited for your video! :-) Thanks for your content, really awesome channel!
@@ranger81de Thank you :)
No, you wrong!! :)) CGA and EGA have analogue RGB, but it have only full ON or full OFF - no gray state. A was have EGA monitor and with a little change in schematic it became common RGB monitor. So, you just plug RGB directly to converter or thru resist divider(5V to 1V)
To merge sync signal you can use resistor and diod and invertor, if it need :)
"...but it have only full ON or full OFF..." - this is exactly how you describe digital output :D
@@necro_ware No, digital have some bits became to different colors, but in this case it only on/off current line - I think it's "binary output", becouse of two state, not digital))
I'm forgot about intensity - but it just add brightness to channel, so you can use resistors plus diode from intensity to make truly analogue RGB :))
I really don't want to argue about this, but MDA/CGA/EGA standards are officially called "digital TTL". If you are really curious, I think Wikipedia is a good start: en.wikipedia.org/wiki/Color_Graphics_Adapter. Digital means, that you have 0 or 1 (0V or 5V) and, that the system can't take any values in between. The thing, where multiple bits are encoding an information, like color, are called protocol and is more advanced digital technology. MDA/CGA/EGA were no so advanced, but still a simple 1-bit digital format. VGA introduced so called RAMDAC, which was responsible to translate digital to analogue signal to provide it to an analogue VGA monitor. So, it is funny, but our first PC monitors were digital until we got analogue with VGA and eventually digital again with DVI and later.
You are right in regards of connecting a digital CGA/EGA to analogue RGB. It will accidentally work, because analogue RGB will try to interpret digital signals and will even get a picture, but your colors will be extremely bright, the number would be reduced to 8 and would look wrong. Furthermore, you would damage GBS-8200 over longer period of time, because it is not designed to constantly hold up 5V on the input.
@@necro_ware I think IBM engineers was "Hi", then they invent CGA/EGA output, or they try to prevent use standard TV with IBM, because it use common TV frequencies - very weird "improvement"))
Same graphic genererator use ZX Spectrum, but it standard RGB+HV output
Works with Jamma boards. Probably not so good for what you are trying to use it for.
Yes, because Jamma is not CGA/EGA, but analog RGBS. This is what I wanted to point out. If you look on the PCB of GBS-8200 you will see "CGA/EGA/YUV to VGA" and this is a lie.
I almost bought this to convert YUV to VGA. Now I figure it won't work.
I never tested YUV with this, I know that CGA/EGA doesn't work, but may be YUV does.
Ega Hclock not 15 kHz ! 60Hz*( numbers row(350) +20...40 )
EGA has two modes low-res is 15kHz and high-res 21kHz. Watch the follow up video for details...
Also disappointed with these Gonbas GBS8200s, that garbage doesn't work either, on my old Dialog4 Deckel FP2NC.
Why advertise it as CGA/EGA converter, if it doesn't work???
I've heard people sourcing components through AliExpress. Based on what I've read about that retailer, and who owns what, I'm not yet ready to trust. Perhaps it works for some buyers, but I don't feel there's enough oversight yet, and the outside world does not entirely trust China itself because of the behavior of its government. Not disparaging the Chinese people at all, who are usually caring and industrious.
In regards of politics, I don't trust any government, they all do very cruel things and sell it as a necessity or charity (depends) to their own nations. China, USA, Russia, EU - for me they all are equally bad guys, however the last one seems not have to much to say in the international politics :) Once it is clear, you will stand in front of the question, if you want to buy anything at all, because once you do, you support one of them. So, if you decide to buy things, it doesn't matter where they are from. And back to topic, GBS-8200 was made and is sold from China only. Everything you can buy in your country is imported from there. If you exclude the reseller in the middle and buy it directly from China, you'll just get it cheaper, but it will be the same product, which will not work with EGA and CGA :)
i think the problem with Chinese sellers is they put extra search terms in the listing that are similar but simply NOT technically correct, so its partly to get hits on a search, and partly the seller does a wide variety of goods but doesnt have the technical knowledge to identify technology components. even if a tech manufacturer copies a product, some dont have proper engineering understanding.