puppetmark Posted April 22, 2008 Share Posted April 22, 2008 (edited) In case anyone has a SC1224 monitor, I designed this circuit so our 8-Bits can use the SC1224 as a Black and White (greyscale) Monitor. Well I use the word "design" loosly. I got the LM1881 part from the Data Sheet and th video Amp is actually from Craig Lisowski's 600XL Monitor Jack Modification. I have this running on my bench now. It really gives a crystal clear output even though it is greyscale. Very easy on the eyes. It would be great for word processing, text based games, music trackers...ect. The circuit is fairly easy to build with some basic electronics experience / knowledge. The LM1881 is a very popular IC and can be found at Jameco, Digikey, or Mouser. The hardest thing to find in the 13 pin male DIN plug that connects to the SC1224. Best Electronics and B & C have them the last time I checked. What I really like about this is that you do not have to modify your 8-Bit. It connects to the monitor jack! This circuit should work with most RGB monitors. I say most because the Hsync output of this circut is actually composite sync and most RGB monitors will accept that as a Hsync signal but not all. Also, this might work with the XEP80 as well but I have not tested that. I am also going to test this with a SM124 monitor. I think it will work but that will just be B & W (no shades of grey) *EDIT* removed pin numbers from schematic to make it easier to read. Edited April 22, 2008 by puppetmark Quote Link to comment Share on other sites More sharing options...
Rybags Posted April 22, 2008 Share Posted April 22, 2008 Interesting. But, can the ST mono monitor cope with 50 Hz PAL input? Quote Link to comment Share on other sites More sharing options...
Bryan Posted April 22, 2008 Share Posted April 22, 2008 Interesting. But, can the ST mono monitor cope with 50 Hz PAL input? He's using an SC1224, a color monitor. Quote Link to comment Share on other sites More sharing options...
puppetmark Posted April 22, 2008 Author Share Posted April 22, 2008 Interesting. But, can the ST mono monitor cope with 50 Hz PAL input? It's true, I am using a SC1224. Its a color RGB Monitor. The LM1881 can handle PAL or SECAM input. If the 8-bit is PAL and the RGB Monitor can handle PAL then the circuit should function just fine. Its really just a sync seperator and a video AMP. Quote Link to comment Share on other sites More sharing options...
+Mitch Posted April 22, 2008 Share Posted April 22, 2008 Out of curiosity, which of three SC1224 models are you using? Mitch Quote Link to comment Share on other sites More sharing options...
puppetmark Posted April 23, 2008 Author Share Posted April 23, 2008 Out of curiosity, which of three SC1224 models are you using? Mitch Version 2. Its a JVC Made SC1224. It has the rectangular on / off switch. Quote Link to comment Share on other sites More sharing options...
+Mitch Posted April 23, 2008 Share Posted April 23, 2008 Out of curiosity, which of three SC1224 models are you using? Mitch Version 2. Its a JVC Made SC1224. It has the rectangular on / off switch. Interesting, I thought the JVC was the first model. Regardless, you can probably skip the v-sync for that monitor since, if I remember correctly, the JVC model can take c-sync. Mitch Quote Link to comment Share on other sites More sharing options...
puppetmark Posted April 23, 2008 Author Share Posted April 23, 2008 Interesting, I thought the JVC was the first model. Regardless, you can probably skip the v-sync for that monitor since, if I remember correctly, the JVC model can take c-sync. Mitch I think JVC did make the first SC1224, but the back of mine says VER2. I will try the composite Sync. Thanks Quote Link to comment Share on other sites More sharing options...
Fletch Posted April 24, 2008 Share Posted April 24, 2008 Any pics of the monitor in action? Fletch Quote Link to comment Share on other sites More sharing options...
puppetmark Posted April 24, 2008 Author Share Posted April 24, 2008 Any pics of the monitor in action? Fletch The clarity is actually better in person but here are some pics. It is cool to see an 8-bit image on an Atari Monitor. Quote Link to comment Share on other sites More sharing options...
atarifan49 Posted April 24, 2008 Share Posted April 24, 2008 I'd be interested to see what XEP80 output looks like on this. Has anyone tried this yet? Quote Link to comment Share on other sites More sharing options...
puppetmark Posted April 24, 2008 Author Share Posted April 24, 2008 I'd be interested to see what XEP80 output looks like on this. Has anyone tried this yet? Not yet but I will. I am not sure how wel it will work, as the SC1224 was designed to show medium and low resolution on the ST Computers. My guess is that it will look as good as any monochrome composite monitor but not much better. We will see. Also, I tried a SM124 monitor last night and it doesn't seem to work. It may be because the luma signal from the atari also contains sync and the monochrome input onthe SM124 may not be able to cope with that. Quote Link to comment Share on other sites More sharing options...
myatari Posted April 24, 2008 Share Posted April 24, 2008 (edited) I'd be interested to see what XEP80 output looks like on this. Has anyone tried this yet? Not yet but I will. I am not sure how wel it will work, as the SC1224 was designed to show medium and low resolution on the ST Computers. My guess is that it will look as good as any monochrome composite monitor but not much better. We will see. Also, I tried a SM124 monitor last night and it doesn't seem to work. It may be because the luma signal from the atari also contains sync and the monochrome input onthe SM124 may not be able to cope with that. The SM-124 runs at 30KHz Hor and 50Hz Vert so will not work with the 8-bit freq or the XEP-80 which both work at 15KHz/60Hz. As far as using this with other RGB monitors the industry seems to change specs all of the time and there is no flat yes no answer. Multi sync monitors that can run at 15KHz horizontal may work. Many VGA monitors will not work at 15KHz and so will not work. Sunc varies all over the place and you have to try it. The XEP-80 is not quite standard frequencies and may not work on monitors that an 8-bit computer does. We have found several Monochrome composite monitors that would work great on an 800 but not work with the XEP-80. Edited April 24, 2008 by myatari Quote Link to comment Share on other sites More sharing options...
myatari Posted April 24, 2008 Share Posted April 24, 2008 Interesting. But, can the ST mono monitor cope with 50 Hz PAL input? The SM-124 works at 50Hz vertical the problem is it runs at 30KHz Hor so will not work. Both PAL an NTSC need 15KHz Hor freq. Quote Link to comment Share on other sites More sharing options...
puppetmark Posted April 24, 2008 Author Share Posted April 24, 2008 The SM-124 runs at 30KHz Hor and 50Hz Vert so will not work with the 8-bit freq or the XEP-80 which both work at 15KHz/60Hz. As far as using this with other RGB monitors the industry seems to change specs all of the time and there is no flat yes no answer. Multi sync monitors that can run at 15KHz horizontal may work. Many VGA monitors will not work at 15KHz and so will not work. Sunc varies all over the place and you have to try it. The XEP-80 is not quite standard frequencies and may not work on monitors that an 8-bit computer does. We have found several Monochrome composite monitors that would work great on an 800 but not work with the XEP-80. I knew the frequency was different for the SM124 but sometimes monitors can cope with different sync reguardless of the published specs. I thought it was worth a try. Thanks for the clarification. Well put: "Sync varies all over the place and you have to try it." I think the XEP80 will work with the SC1224. It seems very forgiving. I think Its worth a try to find out. Quote Link to comment Share on other sites More sharing options...
Fletch Posted April 24, 2008 Share Posted April 24, 2008 Hey, I never noticed that Bruce hung around these boards. I love your store, I just wish my wife loved me shopping there more often. Fletch Interesting. But, can the ST mono monitor cope with 50 Hz PAL input? The SM-124 works at 50Hz vertical the problem is it runs at 30KHz Hor so will not work. Both PAL an NTSC need 15KHz Hor freq. Quote Link to comment Share on other sites More sharing options...
+bob1200xl Posted April 24, 2008 Share Posted April 24, 2008 Do you have an actual store up there? With, like, Atari 8-bit stuff in it? I'm going to move up there... Bob Interesting. But, can the ST mono monitor cope with 50 Hz PAL input? The SM-124 works at 50Hz vertical the problem is it runs at 30KHz Hor so will not work. Both PAL an NTSC need 15KHz Hor freq. Quote Link to comment Share on other sites More sharing options...
puppetmark Posted April 25, 2008 Author Share Posted April 25, 2008 (edited) I'd be interested to see what XEP80 output looks like on this It works great with the XEP80. In fact, I was suprised to see how clear it is! I did have to adjust the vertical and horizontal size but that is often the case when using the XEP80 with almost any monitor. It seems to want to overscan. Here are some pics. As before, it is actually more clear than my camera can show. Also, the hook up is the same except there is just no audio to worry about. No modification is needed on the XEP80 either. Edited April 25, 2008 by puppetmark Quote Link to comment Share on other sites More sharing options...
+remowilliams Posted April 25, 2008 Share Posted April 25, 2008 The SM-124 runs at 30KHz Hor and 50Hz Vert so will not work with the 8-bit freq or the XEP-80 which both work at 15KHz/60Hz. Yup, which is exactly why you can display ST High on common VGA monitors. B & C rocks! Quote Link to comment Share on other sites More sharing options...
+Larry Posted April 25, 2008 Share Posted April 25, 2008 I'd be interested to see what XEP80 output looks like on this It works great with the XEP80. In fact, I was suprised to see how clear it is! I did have to adjust the vertical and horizontal size but that is often the case when using the XEP80 with almost any monitor. It seems to want to overscan. Here are some pics. As before, it is actually more clear than my camera can show. Also, the hook up is the same except there is just no audio to worry about. No modification is needed on the XEP80 either. That is a neat hack! Can you display 80-columns with the XEP80? I only count 75 in your pics, edge to edge, and only 23 lines. This is the "Achielles Heel" of the XEP80 -- overscan. -Larry Quote Link to comment Share on other sites More sharing options...
doctorclu Posted April 25, 2008 Share Posted April 25, 2008 The screen shots look awesome! Good work! Quote Link to comment Share on other sites More sharing options...
puppetmark Posted April 25, 2008 Author Share Posted April 25, 2008 That is a neat hack! Can you display 80-columns with the XEP80? I only count 75 in your pics, edge to edge, and only 23 lines. This is the "Achielles Heel" of the XEP80 -- overscan. -Larry Thanks. Maybe it is still overscanning a bit. I will check. Quote Link to comment Share on other sites More sharing options...
puppetmark Posted April 27, 2008 Author Share Posted April 27, 2008 (edited) Well it looks like on the XEP80 I am getting 78 characters across but the vertical if fine. I tried to adjust the horizontal size on the monitor but I still is overscanning slightly. I may have a fix for this. I will give it a try in a day or two. *UPDATE* Well, I reshaped the horizontal sync pulse but I still can't get all 80 characters on the SC1224. Its a pity really, as the viseo is crystal clear. However, other TTL monochrome monitors may work with this if they can multisync and teh video should be just as clear. If I come across any other monitors to test, I will post the results. Edited April 29, 2008 by puppetmark Quote Link to comment Share on other sites More sharing options...
YSG2020 Posted March 3, 2020 Share Posted March 3, 2020 On 4/27/2008 at 8:40 AM, puppetmark said: Well it looks like on the XEP80 I am getting 78 characters across but the vertical if fine. I tried to adjust the horizontal size on the monitor but I still is overscanning slightly. I may have a fix for this. I will give it a try in a day or two. *UPDATE* Well, I reshaped the horizontal sync pulse but I still can't get all 80 characters on the SC1224. Its a pity really, as the viseo is crystal clear. However, other TTL monochrome monitors may work with this if they can multisync and teh video should be just as clear. If I come across any other monitors to test, I will post the results. Any update to this? I'm looking for a vintage CRT to use with my XEP80 that will display all 80 columns and also match my Atari computer. Thx. Quote Link to comment Share on other sites More sharing options...
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