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O.P.G-RAMIN · Post by **O.P.G-RAMIN** » Tue Dec 04, 2001 5:02 pm

He gezaar I@N well i have all the stuff now :Dbut one thing i wana know it howe do i have to place the ic well do i have to put it like this
with the hafe point down or the hafe point up well i think it's a standerd down righ :)

I@N · Post by **I@N** » Tue Dec 04, 2001 6:10 pm

Umm ... I'm not sure I quite understand what you are asking

Could you clarify your question & I will do my best to help

I@N · Post by **I@N** » Tue Dec 04, 2001 6:19 pm

WilyKat:

I found the technical information document for the 74244 IC, I thought it might help you in trying to find a substitute device:

http://www.maplin.co.uk/PDF/74LS244.PDF

I hope this helps

O.P.G-RAMIN · Post by **O.P.G-RAMIN** » Wed Dec 05, 2001 10:26 am

hE I@N MAN I HAVE A IC CHIP WITH 20 LEGGS 10 on eatch side it's a M74HCT244B1 well i think this gezaar gave me the wrong ic damn it's a 20 legg one not a 6 :)
welll the shematic say i have to get 2 ic well i have 2 ic :) i hink i need one righ. i realy need to know it well i dont have a DPTD Switch :(man can u juse a normaal one
i wana make a inturnole one :D
well hope you replay fast :) like alway's L+::)

I@N · Post by **I@N** » Wed Dec 05, 2001 12:45 pm

Aaaaaaaaaaahhhhhhhhhhhhhhh, I understand.

You only need 1 IC (you have the right one). I will try to re-draw the schematic to make it easier to understand.

you could use 2 SPST switches, it just makes it slightly more complicated to use.

I will post the new shematic later today

I@N · Post by **I@N** » Wed Dec 05, 2001 2:31 pm

OK I've done it.

Look at the 2nd schematic here:

http://www.geocities.com/imhill/dcvga.htm

I hope this helps

By the way, is it me or do these smiley faces (:)) look evil?

O.P.G-RAMIN · Post by **O.P.G-RAMIN** » Wed Dec 05, 2001 3:11 pm

it's looking evil to me Gezaar :D well if you smoke to mutch like i do aaiii wel they look like bobmarly :) well so your frome (egg-ham) or mainstage :D
well thx or the new shem this one look's ok to me :) well hope i can finish it 2 day :) i will make one exturnol 2 :D
Se ya gezaar
Booaycasha

ValeraK · Post by **ValeraK** » Thu Dec 06, 2001 8:17 pm

On mine with VGA-Box all of you very much complicate, in DreamCast is usual, well may be slightly modified VGA the chip, proceeding from this I have connected R-G-B signals directly, and signals of synchronization - through resistors on 120 ohm. Works with monitor Sony CPD-M151 more than half-year without problems. For a sound I use active speakers with subwoofer

I@N · Post by **I@N** » Thu Dec 06, 2001 9:02 pm

Yes it can work without using the chip at all. However, I think this circuit is better because when you boot a game in non VGA mode (for example when booting a game that does not normally support the VGA box), it cuts the signal to the monitor to prevent any damage occuring.

However most newer monitors will be able to handle the incorrect signal, but a few can't.

O.P.G-RAMIN · Post by **O.P.G-RAMIN** » Fri Dec 07, 2001 8:24 am

well man i have your new shem but the switch is difrend hhmm end also the conection points to it :( well i dont know i have 2 switch now end i hop can make it well can you tell me if i still have to juse the dpdt switch :) cas now i have to make 3 hole's in my dreamcast : :( en i dont wana have that 1 for my 50Hz 60Hz end the oder 2 for the cga box man :evil: i dont get it i hope you can tell me wot 2 do :)

PSiEK · Post by **PSiEK** » Fri Dec 07, 2001 4:14 pm

I can't tell from pics and schematic does not say

I@N · Post by **I@N** » Sat Dec 08, 2001 1:51 pm

O.P.G-RAMIN:

I changed the switches on it because you said you didn't have a DPDT one, this way you just use 2 normal SPST switches. When they are both off, the cicuit does nothing so you can connect the console to a TV with a standard AV lead. When both switches are on, the cicuit outputs a VGA signal. However when the RGB switch only is on, the circuit outputs a RGB signal, this is needed for booting games that usually do not support the VGA box.

Obviously if you are making an extenal VGA adaptor, simply connect the RGB pin permamantly to 0v and just use 1 SPST switch on the VGA pin.

I mis-labelled the RGB & VGA outputs on the DC's connector in the first schematic, so I corrected it in the 2nd, sorry for any confusion.

PSiEK:

You can use almost any diodes, I used standard 1N4001 rectifying diodes.

I hope this helps

MidnightObsidian · Post by **MidnightObsidian** » Sat Dec 08, 2001 5:37 pm

Okay. Here's my new deal. I've got a brand new monitor and no money, so I'm going to use ValeraK's design to make an inline external VGA "box".

Before I started on his design, though, I decided to compare the two schematics and I noticed that the RGB lines from the Dreamcast are directly connected to the RGB pins on the 5X3 F-DB (Monitor connector). ValeraK connected them directly, but in both your schematic and my storebought VGA-Box, the dreamcast signal is supplemented with 15volt/220microfarad capacitors. If I am not mistaken, this would smooth the signal. My question is this: are they necessary for a (relatively) safe and reliable piece of equipment? (I was hoping to just solder the thing into one solid cord with only two inline resistors.)

Also, ValeraK uses 120ohm resistors for the sync lines. Your schematic uses 150ohm resistors. For a direct line, would you reccoment 120 or 150ohm? One would think that this would be absolutely critical for a safe, stable signal.

Thanks to everyone for your help and input on this topic!

--Eddie

I@N · Post by **I@N** » Sat Dec 08, 2001 6:05 pm

You could omit the capacitors completely if you wanted, the only thing is that you may find the picture is too bright or too dark (I can't remember which), but you can adjust the brightness of your monitor anyway.

Also while I as making my VGA adaptor, I found that the values of the components were not critical, as long as they are similar you should be OK, the 30ohm difference in the 2 resistors you mentioned should not cause any major problems.

I hope this helps

O.P.G-RAMIN · Post by **O.P.G-RAMIN** » Sat Dec 08, 2001 6:51 pm

well thx ma8 he i dont know howe i i'm gone ask this again but can you please make one with DPDT switch a :D i'm gone make a inturnol one ;) but please give me the one with the DPDT switch end the ic with the 10legg i hope you have time ok man i need it cas i'm gone make the pcb monday i will post the shem for the pcb on monday 2 ok :)
well hope 2 hear frome you soon thx in advance gezaar cya

MidnightObsidian · Post by **MidnightObsidian** » Sun Dec 09, 2001 12:08 am

Okay. It's official. I'm a idiot.

To be completely honest, I was only thinking about using power from a wall socket, but using a backup battery SHOULD work. In fact, you might be able to use the power from the battery that stores the date and time on the controller PCB, because it automatically recharges whenever the DC is turned on. Good idea.

But I stand corrected and quite humiliated. I'm leaving.

MidnightObsidian · Post by **MidnightObsidian** » Sun Dec 09, 2001 12:10 am

F?cking 5hit. This is the wrong topic. I swear, there must have been something in those brownies my mother made today... I think she's trying to kill me.
Either that or I just realized why the peppermint tea I made today tasted so strange.

I@N · Post by **I@N** » Sun Dec 09, 2001 8:20 am

O.P.G-RAMIN wrote:
...can you please make one with DPDT switch...

Here:

http://www.geocities.com/imhill/dcvga.htm

3rd one down.

I hope this helps

MidnightObsidian · Post by **MidnightObsidian** » Sun Dec 09, 2001 9:10 pm

I don't know who was doing that plop shit in my bad posts, but I do have to say that I enjoyed it.

But back to the topic, I finally have all of the parts that I need for my inline adapter. How would you all suggest I put it together? I'm not all too proficient with a soldering iron, just to let you know.

--Eddie

O.P.G-RAMIN · Post by **O.P.G-RAMIN** » Tue Dec 18, 2001 6:22 am

He I@N man i wana know howe many volt' the condesator's have to b en also howe the polorisatie have 2 b it's only saying 220uf :( well i dont get this one 2 work man i dont know wot it is please tell me ok also can you post the pic of your dreamcast whit the vga box in it :) you now the build in one
Cheers

I've got a new mission for all of you Hardware experts!

What kind of Diodes did you use I@N

Simple VGA box

Duh.