4Mb vga resolution

[Casey]

I am embarrassed to admit I don't remember. What are the max colors & max resolution on a vga card with 2Mb video ram, and 4Mb?

Bonus question: thinking of getting a basic soldering iron for simple repairs. Is 30 watts adequate? Haven't used one in years.

 

[Chuck(G)]

Re: soldering iron. Depends on the type and application; 40W is typical. Whatever, get a temperature-controlled unit. You can do a lot of damage to a PCB with an uncontrolled iron.

 

[Timo W.]

I am embarrassed to admit I don't remember. What are the max colors & max resolution on a vga card with 2Mb video ram, and 4Mb?

That really depends on the graphics card itself. Max. colors won't change, as you can do 24 bit already with 1 MB (then limited to 640x480). With 2 MB, you can do 800x600 in 24 bit, and with 4 MB, you could do 1280x1024. With less colors, higher resolutions are possible. Whether or not these are usable depends on the RAMDAC used by the card, however.

 

[GiGaBiTe]

Iron wattage depends on what you're doing. For SMD work, a 40W iron can be sufficient, but for through hole stuff, a 60-80W iron can be needed due to power and ground planes sucking all of the heat out of the iron.

I have a 150W Hakko 551 for really stubborn boards and power supply work where huge power planes and lots of copper wire will pretty much endlessly suck all of the heat out of lower power irons. It'll cut through solder on power supplies like a hot knife through butter and saves so much time and potential damage to components from being overheated.

Another helpful tool to have is a hot air station which can be used to pre-heat the board or remove larger SMD components.

 

[Casey]

Thanks for all the answers! 4Mb sounds like it should be fine. Working on a vintage system that will be plugged into an LCD screen with a native resolution of 1024x768. Not period correct, but $8 at a thrift shop (17") ain't bad!

Was thinking of the soldering iron for 2 uses: one would be adding LEDs (and their resistors) to models. The other would be minor repairs to computers. Some useful suggestions there. As I said, I haven't touched one in years, and that was just for modeling at the time.

Another silly question: is it that difficult to remove an old barrel battery (assuming it hasn't leaked & ruined the motherboard)? Do I need a soldering iron to remove it? I suspect the answer is yes. No specific projects in mind, but it's nice to know these things ahead of time.

Never had to deal with it back in the day as I sold off my old stuff when buying new stuff. I regret selling off a full tower 486dx2-66. That was a nice system.

 

[Eudimorphodon]

With less colors, higher resolutions are possible. Whether or not these are usable depends on the RAMDAC used by the card, however.

The thing to watch out for is many cards newer than the mid-1990's don't actually support "packed" 24-bit color (IE, three bytes per pixel), they need to use 4 bytes per pixel. (The extra byte can be "wasted", or sometimes it's used for tasks like gamma correction.) 1280x1024 is slightly bigger than a "megapixel", so a 32-bit card won't be able to handle it in 4MB. But 1024x768, no problem.

(The rarely-used-in-consumer-hardware 1152x864 resolution that was once common in UNIX workstations and X-terminals is the best resolution for milking the most out of a video card because it's almost *exactly* a megapixel. Unfortunately nobody made LCDs in that size.)

 

[Chuck(G)]

Anent the barrel battery: If you're going to replace it with some external primary cells (e.g. AA batteries) connected to a header intended for that purpose, you can simply clip the leads to the barrel battery. No soldering required.

 

[Casey]

Excellent! Thanks.