Serial output vga input ... - Page 1
Forum section: electronics / beginners

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: June 05, 2013, 07:48:17 am
content: Hello was searching for a screwdriver in my dads shop and i found one old PC ( i dont know the excact specs yet but i will post them later) which outputs to a Serial cable (which went to the broken monitor ( an old CRT monitor i think)).I want to use it with an VGA or even an HDMI monitor is that possible ?Edit :Do i need to buy an adapter like this onehttp://demin.ws/blog/english/2012/12/26/serial-vga/or i can make my own.

author: Psi
author_rank: Super Contributor
timestamp: June 05, 2013, 08:27:44 am
content: Are you sure its VGA, maybe its CGA!

author: westfw
author_rank: Super Contributor
timestamp: June 05, 2013, 08:40:51 am
content: Didn't the monochrome video adapters also use DB9 cables?(yes. MDA, CGA, EGA, and some SUN ECL color video all seem to have used the same connector:http://www.monitorworld.com/Cables/video_standards.html)In those days, the serial port was a 25pin connector (and so was the parallel port.)So you're probably looking at a pre-386 computer (8088, 286, 386, 486, Pentium, Pentium II, Pentium 3, Pentium 4 was the progression. Quite old indeed!)

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: June 05, 2013, 11:41:18 am
content: Quote from: Psi on June 05, 2013, 08:27:44 amThe output is serial and i want to convert it to VGA (or something that is compatible with a modern monitor)

author: Psi
author_rank: Super Contributor
timestamp: June 05, 2013, 12:19:02 pm
content: The only serial screen interface i know of is the ancient outputs for text only terminals.

author: PA0PBZ
author_rank: Super Contributor
timestamp: June 05, 2013, 12:48:56 pm
content: Quote from: ChrisGreece52 on June 05, 2013, 07:48:17 amIf it is serial like in RS232 then it would have been hooked up to a terminal, CRT+Keyboard. Most 'old' equipment had a DB25 connector fir RS232, not a DB9. Are you sure it is RS232?Is it a PC like model with cards inserted? Is the DB9 on a card or on the motherboard? What symbol is next to the DB9? Can you post some pictures external and internal?

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: June 05, 2013, 12:55:51 pm
content: Quote from: westfw on June 05, 2013, 08:40:51 amI am not sure how old it is but it is surely older than Pentium i think its in the age of 286 of 8088ill have to search about it .

author: mariush
author_rank: Super Contributor
timestamp: June 05, 2013, 02:20:14 pm
content: It's not serial, it's CGA or EGA or VGA or it could even be rf modulated (coax, two wire).There are VGA encoder chips you can use (kinda like vga cards in a single chip) , which take the hard work of refreshing the image and rendering away from microcontrollers and also offer built-in fonts (so you only have to send a few bytes to get a whole row of pixels drawn on screen with a built in bitmap font).But with enough MIPS you can drive a vga directly, here's a 48 Mhz PIC doing 256x200 VGA :http://www.pic24.ru/doku.php/en/osa/articles/vga_gameIf you search youtube and various sites on google, you'll find code to do vga out, composite out and if you read about ega, cga etc you can adjust the timings and pinout to do ega, cga etc

author: nuhamind2
author_rank: Regular Contributor
timestamp: June 05, 2013, 03:47:31 pm
content: from wikipedia:Quote

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: June 05, 2013, 08:16:10 pm
content: Quote from: nuhamind2 on June 05, 2013, 03:47:31 pmok so i have to get a decoder chip adapterbut what can i find that will suit my needs?

author: mariush
author_rank: Super Contributor
timestamp: June 05, 2013, 08:24:57 pm
content: No, first of all you need to figure out what type of connector is on that monitor.Get the model number from the back, the brand, then use google and/or ask here what it could be.But I'd suggest you drop it for the moment and get yourself organized and do some of the things you keep asking about. You ask a lot and never "deliver" anything. You don't have to, but it sure would be nice to see you accomplish something and see some results for our efforts in helping you out.

author: C
author_rank: Super Contributor
timestamp: June 05, 2013, 08:37:02 pm
content: Is it really worth the time an effort?What software are you going to run on it?if that old thing has some kind of video connection, You may have to see that old video to do anything. Until you know exactly what standard it uses, it is a shot in the dark. It may also need a keyboard that again is a non standard.Some old computers that supported many users used a serial port for their user interface. At the same time something this old may use a hard drive standard the no longer exists.Could be a real money pit even if you know a lot about the old systemC

author: David_AVD
author_rank: Super Contributor
timestamp: June 05, 2013, 10:37:23 pm
content: I think that really old computers had a "TTL" video output? It was character only and no intensity levels from memory.

author: gnif
author_rank: Unknown
timestamp: June 05, 2013, 11:52:46 pm
content: Is it an AT style computer? Why not open it and find out what the video card/chip is? And if it is a card, why not just source an old ISA VGA card to throw in it, you should be able to get one for cheap from eBay (http://www.ebay.com.au/itm/130918792269)Dont turn it on, TAKE IT APART. Take some photos, try to identify the CPU, see if it has ISA slots, etc... do not assume it is serial because it looks like a serial connector, as others have stated, the DB9 connector has been used for many things, including analog video.

author: David_AVD
author_rank: Super Contributor
timestamp: June 06, 2013, 01:18:23 am
content: Back when the D9 connector was used for video, the serial ports were usually 25 pin. On a PC itself they are the opposite sex (video = female, serial = male) as well.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: June 06, 2013, 08:44:19 am
content: Quote from: mariush on June 05, 2013, 08:24:57 pmThe monitor is thrown the anyway i will search about the pc and i will answer you.As for the other thingsthe mail notification system with the remote door bell is on its way and i am now doing a reasearch on audio ampsbut its all moving slowly i am taking exams so i need to study in one week (when the exam season is over) i will get into the matter

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: June 06, 2013, 08:49:53 am
content: Quote from: C on June 05, 2013, 08:37:02 pmThe thing is that i dont know even what os is running ....ill search about it today and ill answer to all these questions i hope

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: June 06, 2013, 08:51:24 am
content: Quote from: gnif on June 05, 2013, 11:52:46 pmWill do today i am going to retrieve it from the basement and open it up

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: June 06, 2013, 08:59:54 am
content: i have it in front of me but i can see the part number it is removed (the sticker with the part number)

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: June 06, 2013, 09:57:38 am
content: How can i post more than one attachments ?anyway this is a direct link to the album with all the picshttp://imageshack.us/g/1/10182223

author: gnif
author_rank: Unknown
timestamp: June 06, 2013, 11:54:10 am
content: Quote from: ChrisGreece52 on June 06, 2013, 09:57:38 amLink broken...And to add multiple attachments, just click the '(more attachments)' button when you post.

author: nuhamind2
author_rank: Regular Contributor
timestamp: June 06, 2013, 01:17:46 pm
content: Why not just searching monitor model number. You write it attached to a broken monitor so at least the model number still there.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: June 06, 2013, 01:26:57 pm
content: I cant upload the pics thank you thought.The size is 20 megabytes ill upload a zip to mediafire so you can download it and see the pics.LINK :http://www.mediafire.com/download/74soap80ii40p7y/pictures.zip

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: June 06, 2013, 01:28:00 pm
content: Quote from: nuhamind2 on June 06, 2013, 01:17:46 pmWell i think it was thrown away about 2 weeks ago because i could not salvage anything ill search for it tommorow

author: mariush
author_rank: Super Contributor
timestamp: June 06, 2013, 01:54:06 pm
content: That's a Schneider Euro PC 1 or 2 ... probably 1, since it says on the pcb EUROPC (c) 1988.http://de.wikipedia.org/wiki/Schneider_Euro_PCSo it's Hercules/CGA output , 720×348 monochrome or cga 320×200 4 front /16 background colors or 640x200 2/16 colorsAnd you have the pinout here:http://www.allpinouts.org/index.php/CGACGA = Color Graphics AdapterVideotype: TTL, 16 colors.Also known as IBM RGBI.(15.75 KHz - 320x200 or 640x200)Pin Name Description1 GND Ground2 GND Ground3 R Red4 G Green5 B Blue6 I Intensity7 RES Reserved8 HSYNC Horizontal Sync9 VSYNC Vertical SyncYou can generate such signal with microcontrollers, this could point you in the proper direction :http://electronics.stackexchange.com/questions/4172/how-can-i-control-a-cga-screen-with-an-arduino

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: June 06, 2013, 05:32:06 pm
content: Quote from: mariush on June 06, 2013, 01:54:06 pmOK i am not sure how did you do that but i am sure Dumbledore and you shall not excercise magic in the forumThank you anyway i gave the links a loob but i am going to read them in about 2 hours i need to study

author: Paul Price
author_rank: Super Contributor
timestamp: June 06, 2013, 06:33:42 pm
content: You can wire the CGA pins directly into a 15-pin VGA cable and connect to a modern monitor. It should work fine with a versatile VGA or SVGA monitor. You hook red to red green to green... horiz to horiz sync... etc and it should display fine.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: June 06, 2013, 07:02:18 pm
content: Quote from: Paul Price on June 06, 2013, 06:33:42 pmGot it thank you.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: June 06, 2013, 08:45:30 pm
content: Quote from: mariush on June 06, 2013, 01:54:06 pmI found thishttps://code.google.com/p/arduino-tvout/But one of the answer suggested the parallax propeller saying its more powerfull than an arduinoI cant buy a microcontroller since i barelly scratched the surface of the Arduino worldand i think that the mega is powerfull enough for a low resolution rendering./\|Anyway if i use the diagram at the site above | shall i hooke it up by using thisAnd i think its the Euro PC II because it has a motherboard extension slot.(http://www.allpinouts.org/index.php/CGA)Edit : i also found this

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: June 08, 2013, 08:11:33 am
content: The closest thing i could find for my purpose was thishttp://techblog.vsza.hu/posts/Arduino_vs._CGA_part_1_-_flag_PoC.html