This clone CGA/MDA card has a couple of surprising hidden features

well hello everyone welcome back to Adrian's digital basement 2 on today's video we're going to be taking a look at a video card kind of an unusual I don't normally do a video just specifically on one card but there's something super cool about this very cheap clone video card that I think makes it worth talking about and me making a well at least a second Channel video about it the card we're going to be looking at today is an 8bit Isa video card made by the company VTEC and yeah VTEC is the same company that back in the'80s was making apple 2 clones and IBM PC clones it's a Hong Kong company and then they made a whole line of children's educational Computer Learning computer things that they still make all the way up until 2024 or at least I think they do you can see here on the sticker it's a monochrome graphicolor graphics card video technology computers limited made in Hong Kong and there's an FCC ID if you are curious about it now at first blush when you look at this card you might think oh okay it's just a a normal video card and it's probably just a CGA and an MDA card you can see there's a switch right here you can switch between MDA and CGA output they both use the same 9pin connector and it has two video jacks here and if you look on the PCB you can see the top one says mono and this one I think if we move this little transistor out of the way it says color so this is for the CGA video output and normally you have a color composite output so you can hook up a regular color television or whatever to your CGA system that would be just like on the original IBM cards and then you have a monochrome output where the color burst signal is not included and that's extra good if you're hooking up to something like a monochrome composite video monitor because that will make sure that you'll get a nice clear picture without any of the ntsc artifacts that you might have otherwise on the color video output now I actually have a couple of these cards and the other one is basically identical to this except it's missing these two composite video jacks and some of these components over here which are obviously part of the video output circuitry for composite video otherwise the other card is exactly the same with the toggle switch the npin connector it has the light pen connector right here and then the rest of the components are all the same now this particular card is the one I always keep around on the bench in fact I have a little stash of cards over there that I regularly use for testing and I like this one just because it gives me the most flexibility with monochrome and CGA video output and because this has the switch here for switching between the modes it's even easier to use than a lot of the other clone cards which you might have seen they're usually similar sized or maybe a little bit smaller but they have jumpers on them that you have to set to switch between CGA or MDA modes not to mention the composite video output is also handy sometimes if I'm testing out like CRT or whatever and I want to just test a high resolution 80 column text well I can do that very easily with this card so it's a good allaround card but this card actually has some secrets to it that make it even more cool and different than what you would expect so when I first got this card I just assumed it was just a standard CGA 4color video video card and MDA like it just did nothing more than IBM CGA emulation and MDA that's it well one day I was looking at the card and I noticed that it had several jumper locations on the board that were unpopulated and if we flip this over here you can see I've actually done a little bit of soldering on here and this bodge wire is one I did not put on there but that one I did and you can see where I've actually gone ahead and soldered on some pin headers here for various jumpers because I wanted to kind of explore what exactly did these jumpers on here do the ones that weren't populated because maybe there was some extra functionality hidden in this card that I could enable with some of these jumpers now when you look over here in this section you can see the two pin headers that I installed it was this one and this one this set here since there's no flux that was already installed in the board and the way it works is the middle pin here goes to a resistor right there and this is what goes into one of those surface mount chips and setting the jumper either pulls it up to 5 Vols or pulls it down to ground and the way it was wired up originally is I think there was a Trace that just went from probably that pin right to the resistor so on the top side I cut that trace and then I connected the resistor to the middle pin so it matches all three of these resistors and now depending on which position that jumper is in it either grounds or pulls up to 5 volts the input into the chip which goes through that resistor right there so that's why that bodge wire is there and in fact take a look right there you see how you see a little bit of copper right there and that's because I actually cut that Trace that goes from this leg of the resistor R seven which just went to this top pin in position now when we take a look at the ic's on here this is sort of very typical of Clone video card construction these chips here take all of those complicated logic chips and functions that were on the original CGA and MDA card and they combine it into these little as6 that VTEC themselves designed and manufactured over here we have most likely what are ROMs like character ROMs or something like that and up here you can see that we have 64 kiloby of video memory now the thing is that's interesting is that CGA doesn't use 64k of ram it has 16k of ram if I recall off the top of my head and in addition regular monochrome or MDA also has a very small amount of memory because the original IBM MDA standard does not support Graphics modes the thing is though a lot of these types of cards contain 64k ofd Ram specifically for the reason that the MDA emulation is actually Hercules emulation and Hercules video standard does have 64k of video RAM because it supports fonts that can be changed but it also has multiple pages of I think 720x 350 resolution 1 bit Graphics modes and for that it actually has 64k so when you see a card like this with 64k of memory that pretty much is telling you that it is emulating the Hercules video standard but in CGA mode all you're ever going to get is the standard four-color CGA Graphics modes like any other standard CGA card now when I went ahead and installed all these jumpers unfortunately I didn't really take any pictures of the board before I put the pin headers in so I don't really remember what configuration the jumpers were in and then I didn't really know what changing these jumpers was going to do so I just kept swapping them around and changing different positions and trying out all the functions of the card until I discovered this car does some stuff that is actually really cool and I think pretty much undocumented or at least not something that I knew about so in this jumper configuration we have right here this seems to be working in this mode that makes this card far better than I actually expected it to ever be so what I want to do to show this card off a little bit is we're going to take this card and I'm going to switch this into CGA mode so I put the switch in the lower position and we're going to plug this into my 46 test bench right here and this cable right here goes to the rgb2 HDMI so that's just going to be helping me digitize the CGA video output and let's power on the computer here and we should get a little bit of functionality there we go I'm I'm just going to run check it here so we can uh take a look at some of the video modes that this thing supports so we'll do video all tests there we go 16k of ram tested so that's just the normal CGA amount of memory so even though this has 64k because we're in CGA mode programs aren't going to ever see more than the 16k that the original CGA card had so we have four pages of text mode video and that's what that just tested and then we have a bunch of different video modes here that it's going to do a little bit of flashing four sorry about the flashing that's the RGB to HDMI switching modes so everything here is pretty much run-of-the-mill so there's the 16 colors we're going to get on CGA digital TTL where dark yellow is brown which is that column over on the right side there that is completely normal and as expected and when we go to the graphics modes here we have just the usual 320 by 200 and then we have 640x 200 which is what we're looking at right here now 640 x00 is actually in Chrome and that is just how the CJ standard is but 320x 240 does support these color palettes which is cycling through right here and these are the standard CGA color palettes that unless you do programming of the 6845 directly that's just how it's going to work those are the colors you get out of a CGA card and when we hit enter here we're just going to go through some more text modes and we're going to be back at the menu because yep it just went through all the CGA modes this card supports and it all looks perfect now let's run Jim Leonard CGA compatibility test Suite One Thing I think is really great about this card is it actually is very very compatible at least from my recollection so there are border colors that it fully supports and that works properly with some 6845 programming I think that's how it works we're able to change the background color of these Graphics mode so this allows some color palettes that you might not normally see and in addition you can change the highres foreground color it's a little less useful normally it's just white and black but does allow you to pick different colors here and in the 6845 compatibility section this this is where a lot of Clone cards don't always work properly the 6845 IC I think it's made by Motorola is a CRT controller it's essentially what generates the sync signals and drives the refresh lines that go into the video memory and display your image and the original CGA card and the MDA card used a real 6845 so a lot of these clone cards when they have that small surface mount Asic they've taken all that functionality of the 6845 and they put it inside one of those custom chips they don't always Implement all the features or they may not Implement them correctly and Jim Leonard's utility here is really good at picking out where there are issues with the compatibility of that chip which is why he wrote this program the Demo's like 8088 mph really push the 6845 to the limit when it comes to trickery to enable extra Graphics modes and if you want to use a card that's fully compatible with that demo or the demo area 5150 going through this Suite here and making sure that every single thing on here passes is a really good way to test to make sure that the card is going to look good and work properly with those OS I can tell you though that this particular card is very very compatible we'll just quickly Zoom through all these different things here you can see the refresh rate is pretty much spoton it's just off like ever so slightly but it's pretty much perfect this particular test here does some raster bars and yes this is totally possible on CGA and this is happening because of some cool trickery with the 6845 if you have a 6845 that's not totally compatible then this test might break as an example but this is exactly how it's supposed to look and as far as I'm aware this looks perfect this is the row reprogramming section here and this allows these sort of pseudo High color video modes basically it's using text mode but it shrinks the characters down to I think two lines and that gives you this pseudo Graphics mode that allows 16 colors on a CGA card and here's an example of something using that mode and here's another example of something yeah this is coming out of a stock CGA card and I can tell you hooked up to a an actual CRT this image looks absolutely fantastic and this is some of the trickery that's done to facilitate those extra Graphics modes that those demos use and you have to have a card like this one that is fully compatible with the 6845 to make sure that this stuff works properly you can also do larger text mode so see we're looking 80 x 25 and we push a key there now we're looking at 90 by3 now on the RGB to HDMI it's actually cropping off a little bit of the edges but that's just because the the way the settings are on there but it just shows that this card can fully support this enhanced or larger video mode it's removing the borders if you had it on a real CRT you'd have text mode that went all the way off the edges of the screen and then you have this mode here which allows the picture to be moved around and it has to do with the the settings in the 6845 and um that is working that flashing we were seeing there that's the RGB to HDMI but that just allows you to position the image around and the last one here is going to give some scrolling effect and there it is and this again has to do with the uh the start address I don't know if the way it's overlapping there is correct but I think it is either way uh this card is relatively compatible what I'm going to do is I'm going to hook this composite video cable that goes into the Retro tank I'm going to plug this into the color Jack on the bottom here and let's look at how the composite color looks now it looks like the things are a little bit jittery on the Retro tank 5x but that is to be expected it's not really designed to capture text like this let's see if we get some color out of this card here so CGA card determination ah really it's not working very well here so the Retro Tink at least isn't able to decode a color image off this card on this motherboard now the problem is here is that the color burst that comes out of a CGA card even this one here is derived from a clock that comes from the motherboard over the ISA slots and this particular 46 motherboard I think just doesn't output the exactly the right clock frequency so even if I was using a real IBM CGA card it wouldn't be working either now this might actually work fine with a color CRT and it might just be a problem on the Retro tank but I have a feeling it's actually not the problem and I think it's just this motherboard that's not really working properly I found what happens is that the manufacturers of these motherboards didn't really consider anyone using composite color and the Very earliest motherboards like the X XT motherboards had a little adjustable capacitor on them to fine-tune that particular clock that went to the CGA card so that if you didn't have a color image like we wouldn't now you would just make an adjustment on that adjustable cap on the motherboard and then the color would lock in thing is this 46 doesn't have that and like they didn't think anyone would ever use composite so yeah it's just not going to work so this is not a fault of the card this is absolutely a problem with this motherboard and if I put this card into a different motherboard it would probably work now if we switch this over to the other input here which is the monochrome input notice it has no more flashy anymore and that's because there's no more color burst on this particular top Jack which is one of the things I really like about it and if I switch this to svid green/ Blue is it removes the filter that's on the composite input jack on here which results in a much Sharper Image now as far as that static we're seeing again this is a problem with the clock sampling on the Retro tank has nothing to do with the video output of this board it looks Rock Solid when you have a hooked up to a monitor but what I wanted to demonstrate is if I exit out of here now the 80 column text looks a lot sharper there because it's not outputting any of those artifacts for the color like if I switch this back to the color Jack you will see there are now lines visible and that is the color information that could possibly be sent out this color Jack to be decoded by your monitor but if we go back to the mono Jack notice those lines ah it's a little bit dark but there are no more lines or anything everything looks much better and if we go up to color here I kind of show that as well so there we go it's just nice Shades of Gray now and if we switch back to the color Jack now you can see those lines there which is completely appropriate and understandable and yes in case you weren't aware CGA color composite video output does use ntsc artifact color exactly like the Apple 2 did so that's why you're seeing those vertical lines which look just like Apple 2 color now incidentally we're back on the RGB to HDMI this is just a little cool thing about it is that it actually has the ability to decode composite color through a CGA adapter so if we go to composite Lowes there we go we're getting a black and white image over TTL RGB but you can notice those lines which is artifact color and if we go into the menu here you can see it says CGA ntsc artifact and if we turn that on we are actually going to get the color decoded now the colors look wrong so notice like 14 says Rose and it's actually yellow and unfortunately that's one of the things about CGA color that actually causes problems on real CGA adapters IBM CGA color output pretty much always has the same phase so you're always going to get the expected colors when you're hooked up to the RCA jack but thirdparty cards don't always work the same way when it comes to the phase of the video signal coming out now what's cool about the rgbd HDMI is we're decoding the artifact color in the RGB to HDMI based on a TTL video signal and it allows us to actually adjust the phase so we can go through here until we get rows so it looks like 180° I think is the correct phase um no not quite actually in fact this looks to be the right phase other than the fact that red number 12 there is actually showing up as orange but that's probably just a an artifact of the way the RGB to HDMI decodes the color because the rest of most of these colors are actually all completely correct and there's a couple other settings you can do you can do sharp mode soft mode which adds a little bit of like color fringing around the text normal I actually like to use the sharp mode what's cool about this artifact decoding on the rgbd HTMI is that you can actually play old games that were designed with CGA artifact color in mind and allows you to see the way they were intended with additional colors that original CGA didn't support now the problem is when you exit out you go into ad columns mode the artifact color still enabled and that's why everything looks like this because this would actually be what it would look like if you hooked up an ntsc color television and the color burst were enabled or output from the RCA jack that's how the text would look very hard to read Let Me Show an example of a game running in artifact color mode I'm going to pick number two there composite 160 by 200 at 16 colors and we'll do PC speaker and there it is so this is how it would look theoretically if you were outputting this game on an actual composite color monitor ntsc one through the RCA jack on your CGA card what's cool about this game by David Murray as well is I think it allows you to change the phase that's what this is doing is that phase option which we had inside the RGB HDMI this allows you to pick the correct one so that you can get the correct colors no matter what the manufacturer of your CGA card is using for the phase output of the composite video obviously the correct color phase would be the road is that brownish color and the trees are green and you can see this is looking yep pretty good and this is all coming out of a stock CGA card now if I hold down this button on the RGB HDMI there we go it disabled the artifact color and now we're just looking at what planet X3 is generating through the TTL RGB and this is what would be decoded into color with a composite monitor okay so what I really was just trying to demonstrate there by all that was I just wanted to show that this is a great CGA card it works great and unlike the real IBM CGA card it doesn't have that flicker or any of the CGA snow so it's actually a better and more improved CGA card over that not to mention the fact that it's got these two Jacks here with that nice smooth monochrome composite output it just means that this thing is incredibly versatile when it comes to CGA now back to this jumper stuff that I've installed with the Jumpers in this exact configuration so I'm just going to zoom up here so you can actually see them so jp6 is over on the right this jumper right here is actually just not installed that's jp3 jp5 is in the lower position and then those two jumpers are in the upper position that's JP 2 4 and 5 in this exact configuration right here this card has some extra superpowers so let's just pop this back in the machine here I didn't change anything this is exactly how it was already configured when I was just demonstrating how good of a CGA card it is and I'm going to run through all the different video modes here on planet X3 and this is exactly what I did for testing when I was experimenting with these different jump configurations so I kept changing things on here and then running through all these modes so I started with option one there which is just CGA I'm going to pick ad lib so so we don't hear any music or anything yep there it is just a standard four-color CGA color palette and it allows swapping the the palette around that's in the game once you're in the game mode so nothing to really talk about there that's just as expected uh I'll skip over to we already know the composite mode works because I was just demonstrating that uh we can do the highes mode which is just well it's monochrome mode it uses sort of Shades of Gray by dithering basically and that obviously works but that's nothing special that would work on a a standard CGA card now we have number four here which is a Tandy mode 160x 200 in 16 colors now the Tandy Graphics mode is actually 320 x 200 at 16 colors but David just uses this lower res which I think works on some machines that have less Ram or something like that if we pick that mode though it does this which is completely standard that's what's going to happen if you try to run a Tandy mode on a machine that well doesn't support Tandy you're going to get that so exit out and now I'm going to do option five which is 320x 200 add Gray Shades and that's not working properly so I think if you try that mode on a card that doesn't support this four Shades of Gray you end up with this particular color palette so you get white black the reddish color and then the cyan color I've tried this on other CGA cards and I'm not sure I've ever had any card that actually supported this particular mode so that's just an interesting curiosity and no matter how the configuration of the jumpers were set on this thing it just never supported that particular mode and the next option is six and look at that so this is the secret that I wanted to talk about that whole leadup was to get to this that with the Jumpers in this configuration this card is now fully Plantronics compatible which means it has full 16 color Graphics support which essentially is the same thing as the Tandy mode and it's a hidden feature the way the jumpers were configured on this card out of the box did not have this mode enabled because believe me I tested all of these modes just to see what this card could do and then I started fiddling around with all the jumpers on this card to try to see what I could discover and I discovered that in this exact config now it supports this Plantronics mode now the Plantronics mode is an extension of CGA and if you don't have a card dis Plantronics compatible what happens when you try to run it is you end up well you end up with the four-color CGA palette the way this mode works from my understanding is there are additional bit planes enabled to allow those extra bits of color to give you the 16 color palette and for a car to support Plantronics video mode like this it does need to have 64k of ram which obviously this card does have but yeah this card is fully Plantronics compatible with the jumper set in this configuration which is an awesome little bonus now there are very few programs that support it I think I have robots on here uh which is Attack of the petsky robots does this support Plantronics oh yes it does number seven let's just see how this looks I'll do new music and look at that that is really cool to see fullon 16 colors coming out of this I thought just the normal CGA card and it looks absolutely great look at this look how cool it is this would be the same color palette as you would usually see in the Tandy Graphics or PC Junior Graphics not to mention EGA card Graphics as well and thanks to David Murray for implementing these modes in his two games I don't know how many other games are out there that support it but there is at least SE show which is like a graphics image viewer and I think there's a fractal viewer as well or fractal you know artwork viewer that supports Plantronics as well but it's just pretty cool to know that that feature was dormant inside this card and just changing around a few jumpers suddenly enabled it now that's not the only cool feature that I figured out about this card so let me move on to the next one I'm going to power off this machine here and I'm going to switch the switch here into the MDA setting and on the RGB HDMI I'm going to switch this thing over to Hercules because that is basically what this card is emulating and we turn the computer back on hopefully we'll have an image yes we do now remember I didn't touch any of the jumpers this is just exactly how it's configured on here well as I showed a moment ago switching between the CGA Plantronics mode and MDA just requires flipping that switch it's it's that easy now all is good this is a fully Hercules compatible card uh the fact that the cursor looks like it's in the wrong position has to do with this Nancy driver that I'm running here which is like a high-speed anti driver if I take that out it doesn't have a problem with the cursor so that's not related to this car that is just a thing with this particular video driver so running Planet X3 here if we pick Hercules which I guess is 640 by 300 uh the resolution is actually by 350 so that's why it looks a little bit squished right now and um the the horizontal resolution is actually 720 but because David's graphical assets for this game are not designed for 720 x 350 he just puts a border around it but there we go the card is working perfectly in Hercules mode and yeah it works flawlessly actually uh as I mentioned before the Hercules mode is only one color so it's just one bit so it's black or white and that's all you get out of it now using this card here if we run like the edit utility everything just works as expected you end up with essentially white black and a bright white so well let's see if I can show that off here in the edit so you see the the letters there new open and save those look brighter and that's just the intensity bit being set on the output from the TTL Jack right here and if we run the CGA compatibility Suite there we go this card is actually really designed to be used on a CGA card so it's not I don't know the reason why like the the buttons are hard to read there and you can't really see the menus and stuff is just because Jim is has designed this program to work on a color card and not on a black and white card like this but essentially the BIOS knows that this is a monochrome card and so does Dos that means any programs that run they supposed to look that up and then honor the fact that it's a monochrome card and just use that intensity or bright white and dark white and then the black background color and then the main feature over CGA and the reason why people liked MDA is because you have a higher resolution text but the way that IBM implemented MDA over CGA is that they got the higher resolution those 350 Lines by slowing down the refresh rate and the refresh rate of monochrome is actually 50 Herz versus 60 on CGA and that allowed them to squeeze those extra lines of text in Without Really changing too much outse about the way the monitor Works standard ntsc video which is what CGA is runs at like a 15.7 KZ horizontal scan rate and to also increase the number of lines from the 200 all the way up to 350 they slowed it down to 50 HZ and they also increased that horizontal scan rate I think to around 18 something khz it meant that that's still within the realm of most monitors just with some minor changes that just allow them to display that extra resolution but you did have that extra flicker which is why the original IBM monochrome monitor had a long persistence phosphor to try to minimize the amount of flicker you get from 50 hurts anyhow there's not really a whole lot to say as I said about this card it is fully MDA compatible but one day I was fiddling around and I noticed something kind of interesting about the way the card worked and I noticed it specifically because of the RGB to hdmis flexibility now if I go into the menus on the RGB HDMI and I go to the pallet menu currently it's set to MDA Hercules and what this setting is doing is it's telling the RGB to HDMI to look at the specific pins that come out of the npin Jack here for the video signal signal and the intensity bit and the pallet setting here is essentially telling the RGB HMI to ignore the RGB signals that are coming out of the N9 pin because if you look at a pin out for MDA versus CGA the video signal is on a different pin than the RGB signals that are on a CGA card the intensity bit is the same between the two of them but it's that extra video signal on MDA that does come out of a separate pin that means if you take a CGA Monitor and you plug it into a standard MDA card well not only is it going to not be able to synchronize to the video signal you even see anything on screen because the CGA monitor is only looking at the RGB pins and the original MDA card didn't have RGB pins on it and of course vice versa using an MDA monitor on a CGA card means you're not going to see any picture either it's not going to synchronize or you won't see a picture and that's because the MDA monitor is looking at a pin that doesn't exist on the card because CGA cards don't have anything wired up to that pin now this card here because it obviously supports CGA and MDA and there's a toggle switch clearly it's wired up to the RGB pins and to the MDA pin and to the video output pin that's used for MDA on the 9 pin Jack now if we go to the pallet option here and we scroll through here and we scroll over to rgbi which is exactly the setting that's used for CGA that is telling the RGB to HDMI to start looking at the RGB signals that are coming out of the video card on a true MDA card you're actually not going to get anything at all you'll just have a black picture but on this card it seems to actually be outputting the video signal on on the RGB signals along with that extra pin that's used for the MDA monitor so here in edit you can see this we're getting actually the same image that we were getting before which is just a black and white image with the bright white there for the little marks and see on the menu there it all looks exactly the same now exiting out of here look at this color so that's the other thing I want to talk about this card is it actually support color on monochrome now if you do a little bit of reading online you'll find that I M's designed for the original MDA card the one that was released with the IBM 5150 the first IBM PC it seems that they had actually intended to have color support on the monochrome video signal there's some rudimentary work on the card there to enable that and I can't remember if it's possible with some extra wiring to enable the color output but it does seem that originally IBM had envisioned a higher resolution MDA text mode that did support color but it just never got implemented either for cost reasons or like what whatever the reason but for whatever reason this card from VTEC implements the color MDA mode so if we run jyim Leonard CGA compatibility Suite there it is we're in full color in MDA mode and you can see with the high resolution text there that we are indeed in MDA mode we're not in CGA mode and we can go into the info menu and take a look at the source info there and there it is you can see we're running at 49 Hertz so I guess it wasn't 50 it was actually 49 and you can see the capture size is 728 by 350 I think the couple extra pixels are just off the edge of the image it's actually 720 wide so indeed the RGB HDMI allows us to look at this color MDA signal now the thing is I'm not sure of any monitors any actual physical CRTs out there that would display this mode probably a multisync monitor one of the old multisync monitors the ones that can actually do 15 khz and all the different RGB modes might be able to do it because generally those can sync up to all sorts of different sync ratios and there's a physical switch on the monitor to pick between monochrome video input or RGB input so I think switching to RGB input and then the sync signals coming in off the MDA card it would probably work with this particular card but if you want to see what color monochrome looks like there it is right there this VTEC card fully supports it and I mean as you can see here it really really does and I think if we go to color here um oh that's interesting so for whatever reason the way that Jim is doing this card here it's not writing the color to the card well that is oh look at that rgbi is okay I think this is a setting on the RGB HDMI notice it doesn't have the brown color I think if we go into here into the color palette there it is there's a CGA option here which gives us the the brown that is just a decoding thing in the RGB HDMI it has nothing to do with the actual signals coming out of the card but yeah you can see there that we have all the colors available to us all 16 colors that you would have on CGA or any other TTL RGB type card and I think none of the other things in Jim's program will work properly here and that's because the card truly is running in MDA Hercules mode right now so none of the CGA Graphics modes will work at all so I can't like pick any of these modes here and have it actually function the color one was sort of working because this is just strictly using a text mode and I think Jim just writes to the video memory directly on the card and is writing color information into the video memory which is why we're seeing color here but but when we exit the program and we run a program like edit we're seeing it in black and white specifically because this call this program checks the BIOS and goes oh we're in an MDA card so it doesn't even try to display color and I think most programs are going to work that way but my hot directory program here doesn't seem to care about that I think this was designed in like the '90s and it doesn't even consider that someone has a monochrome card so it just writes the color information directly to the frame buffer as well and there you go you you can see we have fullon color now let's see what other programs actually display color like how about landmark speed test let's doing color there oh okay well that didn't work cuz I have to reboot with a shift held down obviously the BIOS is not going to do it because yeah that's just going to display it in monochrome because it knows we have an MDA card so it doesn't even try like if I do shift F2 it's just going to go through like the well the two monochrome palletes that are in here my assumption is if you took uh IBM MDA card and you modified it for color output that it would would work exactly the same way as this that most programs would just only run in monochrome because they honor what the BIOS says and then other things that just write directly to the video memory and ignore what the BIOS says like what's happening there and like what's happening right here would actually show color on the actual IBM card as well let's run n format no n format does honor the monochrome mode properly so that doesn't do anything how about IMD oh IMD kind of interesting so the help mode has green text but the rest of the program is running in monochrome mode so that's sort of like a a pseudocolor mode normally this if you display it in a on a color video adapter you'll have a blue background with red at the top and stuff like that I'm going to run Jim Leonard's top bench my assumption is he's going to have used the same code to display theat text mode that he used in CGA compatibility so it's going to be color as well and yep it certainly is and oops and this doesn't have any kind of Graphics mode so yeah there we go Totally Running in uh te color text mode on an MDA card I mean it's kind of a useless thing what's happening here like there's no real use for this but I think it's just really curious that this card fully implements this color MDA mode and I don't know if it's by accident or on purpose or what the deal is but it just it does implement it properly and seems to work perfectly now if we go into the pallet mode here in the RGB HMI and we and we switch this back to Hercules mode mode now it's going to be pulling the video signal off that other pin and this card does correctly output that video signal so here we are in top bench and this is exactly how it would look on a real IBM MDA card hooked up to a real IBM monochrome monitor so there we have it that is the VTEC CGA MDA card that does a lot more than you would first imagine if you happen to have one of these I highly recommend that you break it out and you play around with it a little bit make those jumper changes that I showed on here I don't remember which jump actually enables the Hercules so you could try all the jumpers except for the one that you have to make this cut on the board for first and then you can see if you have the Hercules or not Hercules the uh Plantronics mode enabled and if not then you might have to install that jumper if I recall it was one of the jumpers up at the top here that enabled the Plantronics mode so I don't think you have to even touch these ones down here just leave them the way they are and install the jumpers up here and have it in this configuration I already really like this card before I did these mods to it and now I love it even more because it's just really cool to have a card that has all these cool modes available to me to use especially the Plantronics mode because i' actually don't have any other cards that I'm aware of that support the Plantronic 16 color mode except for these VTEC cards and these cards as I mentioned were found in many of Vex clone computers the early ones so they seem to be not hard to find I don't know like what the prices are these days if you look on eBay and I don't know how common these are to be found at all but as I mentioned I've ended up with a few of these just over the years and I just used this one cuz I thought it was cool and then I didn't realize how much cooler it actually was so I hope you enjoyed this video this little expiration of this cool video card if you did thumbs up all the usual stuff huge thanks to my patrons their names are scrolling up the side of the screen over here they make a possible I do this fulltime if you want to become a patron there's a link description below um what I was going to say yeah you know subscribe all the usual YouTube junk and I think that's going to be that so St stay healthy stay safe and I'll see you next time bye-bye

Channel: Adrian's Digital Basement ][

Views: 40,752

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Id: JljZ4OEZ5nI

Length: 36min 28sec (2188 seconds)

Published: Wed Mar 20 2024