Re: VGA color adapter and color monitor, hardware force to monochrome.

Posted on 2018-01-23, 00:10

by

by retrocanada76

in Marvin \ Video

in Marvin \ Video

This thread reminds me of my self-made VGA cable for the Atari ST. It works pretty much in reverse to what you people said. http://atariage.com/forums/topic/170385-st-to-vga-monochrome-only-adapter/ sure it will work: you connect them all in parallel. You just need to find the correct voltages as …

---

Re: VGA color adapter and color monitor, hardware force to monochrome.

Posted on 2018-01-22, 22:28

by

by retrocanada76

in Marvin \ Video

in Marvin \ Video

I have a vga that can be jumpered to greyscale , I don't think that putting resistors on the RGB line will remove color alltogether... maybe your card has a utility to force MONO mode? sure it will work: you connect them all in parallel. You just need to find the correct voltages as the monitor …

---

Re: MDA/CGA/EGA to VGA Converter Released!

Posted on 2018-01-22, 18:02

by

by retrocanada76

in Marvin \ Video

in Marvin \ Video

Hmm well you shouldn't be using my pictures as an absolute reference. They obviously aren't proper VGA captures just pictures of my monitor, and the exposure of the camera isn't constant. I thought the colors looked ok on mine before but I updated with the latest code. To be honest I don't notice a …

---

Re: MDA/CGA/EGA to VGA Converter Released!

Posted on 2018-01-22, 14:49

by

by retrocanada76

in Marvin \ Video

in Marvin \ Video

check if you have the very last update. I updated the code few hours ago. I fixed the bright levels compared to plasma screen.

---

Re: MDA/CGA/EGA to VGA Converter Released!

Posted on 2018-01-22, 06:48

by

by retrocanada76

in Marvin \ Video

in Marvin \ Video

Ugh, that means my colors were a little off. Try the new firmware, close colors to the reference and longer OSD time

---

Re: MDA/CGA/EGA to VGA Converter Released!

Posted on 2018-01-21, 23:31

by

by retrocanada76

in Marvin \ Video

in Marvin \ Video

It's difficult to tell. I think maybe your dark gray is too light. We should probably be using a proper EGA color test program to compare. Are you using 2% resistors? these are CAT16-102J4LF, they are 5% maybe it is that I use 5% on my designs. I only use 1K resistors. Is it the same for your board …

---

Re: MDA/CGA/EGA to VGA Converter Released!

Posted on 2017-12-25, 09:31

by

by retrocanada76

in Marvin \ Video

in Marvin \ Video

yes all 64-colors are displayed. Where can i get your test program ?

---

Re: MDA/CGA/EGA to VGA Converter Released!

Posted on 2017-12-25, 02:06

by

by retrocanada76

in Marvin \ Video

in Marvin \ Video

retrocanada76 wrote: (64 colors) and will not look good. sigh, in fact it has 512 colors but it's not enough for an amiga you only get 8 shades of each color and they get lots os flicker.

---

Re: MDA/CGA/EGA to VGA Converter Released!

Posted on 2017-12-24, 19:31

by

by retrocanada76

in Marvin \ Video

in Marvin \ Video

a REALLY usefull thing for me would be an external Scandoubler for the ST. I get a really nice and sharp image on my TFT with an A2320 (31.5khz 50hz), but on my ST the picture is really bad on lowres and medium/high as well. (with 15khz/50hz which the LCD supports) No amigas, this is a pure digital …

---

Re: Fastest "Turbo XT"

Posted on 2017-11-30, 18:39

by

by retrocanada76

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I recently overclocked my PC 5150 using the PC-SPRINT schematics. I'm using a crystal of 17.43 which gives me 5.81 Mhz on a NEC V20. I tried a 22.1Mhz (7.33mhz) but my memory is too slow (200ns). I will try with higher clocks (19mhz for example) once I get them in the mail...

---

Re: Getting an old PC to boot from floppy

Posted on 2017-10-31, 18:05

by

by retrocanada76

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

there are external USB 3 1/2 floppy drives easily found on eBay. Caution must be take if you are targeting 720KB disks are not all these support 720KB, but 1.44MB you are ok. Then plug into your modern PC (it works on windows 10!), format, copy a floppy image of DOS using Win32Disk or WinImage, etc …

---

Re: Super PC/XT Bios BUG for 5150

Posted on 2017-10-22, 06:44

by

by retrocanada76

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

CL is being set to 4 again few lines below, for another shift, so it's safe.

---

Re: Super PC/XT Bios BUG for 5150

Posted on 2017-10-22, 00:52

by

by retrocanada76

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

As someone else pointed out in other forum SHR AL,4 is not valid but TASM is expanding to to 4 SHR AL,1. The correct would be: MOV CL,4 SHR AL,CL

---

Super PC/XT Bios BUG for 5150

Posted on 2017-10-21, 21:10

by

by retrocanada76

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I noticed the Super PC/XT Bios didn't work for my 5150 especially when activating the IBM_PC=1 flag or using the PC/XT version with mono card. It turns out it reads the SW1 wrong, there is the fix: ifdef IBM_PC ; Read 5150 switch config mov al, 0CCh out dx, al ; Reset keyboard in al, 60h ; Read …

---

Re: MDA/CGA/EGA to VGA Converter Released!

Posted on 2017-10-15, 19:49

by

by retrocanada76

in Marvin \ Video

in Marvin \ Video

Yeah go ahead. Just don't remove my credits from the PCB...

---

Re: MDA/CGA/EGA to VGA Converter Released!

Posted on 2017-10-07, 20:32

by

by retrocanada76

in Marvin \ Video

in Marvin \ Video

Like this one ? Just search for CoreEP4CE6: http://www.ebay.ca/itm/ALTERA-FPGA-EP4CE6-EP4CE6E22C8N-Cyclone-IV-Development-Evaluation-Board-Core-Kit/251194080650?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160908105057%26meid%3D226b62c3f1464ee5ba91fe314aefb411%26pid%3D100675%26rk%3D3% …

---

MDA/CGA/EGA to VGA Converter Released!

Posted on 2017-10-07, 09:13

by

by retrocanada76

in Marvin \ Video

in Marvin \ Video

Creating a new thread for the launch, any doubts about the project you can post here... https://sites.google.com/site/tandycocoloco/mda-cga-ega-to-vga Gerber files available and FGPA code released. Enjoy. I am having trouble playing with different CGA boards, I should make the output as 720x400 and …

---

Re: DIY: FPGA MDA/EGA/CGA to VGA Converter :D

Posted on 2017-10-06, 17:45

by

by retrocanada76

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Maybe you can put a sync between then and only trigger next VGA frame after the NTSC completes the first.. who know there is a lot of things you can do, like strip all EGA/MDA modules and clock and lock the 2nd PLL to VGA 25.175 and make it to sync with the incoming CGA NTSC...

---

Re: DIY: FPGA MDA/EGA/CGA to VGA Converter :D

Posted on 2017-10-06, 17:43

by

by retrocanada76

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

It is a 256K x 16-bits chip. The lines take up to 800 overscan pixels. So for every line 1024 bytes are taken. So this leaves me with 512 lines maximum. It could be used for the CGA 200 lines to double buffer it, you can change it if you want that's the fun. But not for 350 resolutions. But... the …

---

Re: DIY: FPGA MDA/EGA/CGA to VGA Converter :D

Posted on 2017-10-06, 16:58

by

by retrocanada76

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Right, but this is not a line converter. And it does Hercules (50Hz, 16.000Mhz) pixel perfect as well, what would be impossible for a line converter... https://www.youtube.com/watch?v=dXUh4QoPmbk

---