Re: MDA/CGA/EGA to VGA Converter Released!
Posted on 2018-02-23, 04:49
someone must donate one board full loaded to The 8-bit Guy for him to test 😀 he is doing a Tandy 1000 game....
Re: MDA/CGA/EGA to VGA Converter Released!
Posted on 2018-02-23, 04:46
Great fine job btw 😁
Re: MDA/CGA/EGA to VGA Converter Released!
Posted on 2018-02-23, 04:46
add a ceramic 0.01uf capacitor between the VCC and GND but that's is optional.
Re: Subtle Waves on Old Tseng VGA Card
Posted on 2018-02-22, 05:11
could it be the cable as well ? Is it a shielded cable ? try making a loop with it.
Re: MDA/CGA/EGA to VGA Converter Released!
Posted on 2018-02-21, 05:44
Yup that's the idea. a bussed 8 resistor 4.7k will make the job. Job solder ir under the board. it would be wiser to add a 0.01uf capacitor on this TTL as well. I will make a version 2.01 later
Re: MDA/CGA/EGA to VGA Converter Released!
Posted on 2018-02-20, 20:33
I think you can start with 4.7K or 10K, you need to feed all 8 pins of the 74ls245. If it was my board design this could be easily doable soldering one of these in the back of the 74LS245, connecting the ground to the common pin: https://www.digikey.ca/product-detail/en/bourns-inc/4609H-101-472LF/ …
Re: MDA/CGA/EGA to VGA Converter Released!
Posted on 2018-02-20, 17:52
You can add pulldowns, not change in the FW, they will be before the 74ls245 unfortunately to only way to write to this FPGA board is through a blaster.
Re: MDA/CGA/EGA to VGA Converter Released!
Posted on 2018-02-20, 00:56
Is it better to force it than auto-detect? Auto-detecting should be possible, if there's room for it? It would require a lot of testing and measurements. It should be the time between the hsyncs to be measured. And then from mda to hercules it would be pratically impossible. The difference is too …
Re: MDA/CGA/EGA to VGA Converter Released!
Posted on 2018-02-20, 00:53
try the new one, I turned the voltages back to 2.5V
Re: MDA/CGA/EGA to VGA Converter Released!
Posted on 2018-02-19, 20:30
But I see that there's no pulldown resistors on the converter DB9 connector, so if the EGA card tri-states the unused pins or it is connected to CGA card, the voltages can float at indeterminate levels as there is nothing connected to them. This shouldn't be a problem because the sync levels …
Re: MDA/CGA/EGA to VGA Converter Released!
Posted on 2018-02-19, 19:38
In the commit: "Calibrate the CGA colors according to CGACAL" I also changed the voltage of the pins from 2.5V to 3.3V to have voltages close to 0.7v as required to VGA. Could be it ? Try the commit previous this one.
Re: MDA/CGA/EGA to VGA Converter Released!
Posted on 2018-02-19, 19:35
you should get a decent blaster. The .sof files are temporary, you load them and they just keeps until you press config button or turn off the board. But they are good to test without flashing the board. The .jic are the ones to be permanent in the flash ram. But if it's you blaster to blame there …
Re: MDA/CGA/EGA to VGA Converter Released!
Posted on 2018-02-19, 17:32
I did not have these issues with the previous firmwares (maybe I didn't write it clear enough), there was always a combo that it worked and produced a clean picture. This behavior started with the very latest fw update. can you try an older FW ? You can get previous versions directly from website: …
Re: MDA/CGA/EGA to VGA Converter Released!
Posted on 2018-02-19, 15:14
it's should be grounded when emulating CGA output. otherwise it shouldn't. How SW8 affects the image ?
Re: MDA/CGA/EGA to VGA Converter Released!
Posted on 2018-02-19, 14:22
I'll have to do some more research on this. From the manual for the Multisync monitor; Capture.JPG With the manual color switch off I get similar colors that I see using the converter. With it on the colors are good. So it would seem that the EGA Wonder does not work quite the same as the IBM EGA …
Re: MDA/CGA/EGA to VGA Converter Released!
Posted on 2018-02-19, 14:16
what is green screen + reset ? Are you talking about the greeen monochrome emulation ? I have changed the dip on the board to be the same as MDA/hercules. So now the green screen is the dip3. Dip4 choose green/amber. You can test an olde FW, like the first one with OSD. But What I see is problem …
Re: MDA/CGA/EGA to VGA Converter Released!
Posted on 2018-02-19, 06:13
I mean in the board, go to the 74ls245 and on until you get into the FPGA
Re: MDA/CGA/EGA to VGA Converter Released!
Posted on 2018-02-19, 06:13
I know EGA cards needs a jumper to use the pin 2 (secondary red) otherwise it will be grounded. This could shift the colors. If I don't set this jumper I never get full white. I just tested my ega card and is fine. Can you check if any of your Secondary red, green and blue are shorted ? Because …
Re: MDA/CGA/EGA to VGA Converter Released!
Posted on 2018-02-19, 05:44
I know EGA cards needs a jumper to use the pin 2 (secondary red) otherwise it will be grounded. This could shift the colors. If I don't set this jumper I never get full white.
Re: MDA/CGA/EGA to VGA Converter Released!
Posted on 2018-02-19, 05:20
i didn't notice on my monitor I will check but could it be the settings on your monitor ? Since they are different resolutions the monitor could store multiple settings.
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