Circles are not round on my screen

Well it's like this: in 800x600 fullscreen circles drawn at the top or bottom of the screen are round but as they are drawn closer to the middle, they elongate vertically by a little bit (but it's noticeable on my 19" CRT). In 1024x768 mode (windowed) this isn't an issue.

Weird or what! I spent ages last night trying to figure out in my code where I'd used SetScale incorrectly but it turned out to be my screen instead - crazy but true.

Probably because your monitor's native resolution is 1280x1024, which has a slightly different aspect ratio to 800x600 and 1024x768.

You'll find circles are slightly oval in 1024x768 fullscreen, too.

Is this a joke?

A perfectly round circle would require an aspect ratio on your screen of 1:1, you have 4:3.

for every four pixels sideways, there are three down, indiepath... they're still arranged in a grid of 'squares'.

...and pixels are not necessarily square.

yeah but no one has listened properly. They are round on one part of the screen and NOT ROUND on another part of the same screen!

800 by 600 should give square pixels. Many CRT monitors have all sorts of geometry options you can fiddle with to correct this kind of thing.

My computer monitor noticably increases width at the top and bottom of the screen, at certain resolutions anyway. To fix it I had to go into the monitor setup and shrink the screen size down a little bit.

It is kinda neat though.

Yeah, as dynaman said, looks like you got some monitor-tweaking to do with the 10 some settings they got.
(thank god for DVI cables & LCD monitors...)

Sounds like a monitor geometry setting problem... which you may be able to correct by some tweaking, or if you're out of luck it is not user adjustable.

Once had a CRT going bad where the the screen was stretched exponentially in the horizontal...
The graphics on the left side of the screen were all stretched out way too far, and those on the right side were very much compressed... to the extend that the right 1/3 of the graphics were all scrunched together in two inches or something... also a much increased brightness on that side of the screen thanks to more exposure to the electron cannon I suppose.

Grey Alien,

It's called the "Pincushion" adjustment, which alters the linearity of the screen.

Not many modern CRT monitors that I've seen lately actually have a pincushion that is adjustable by the user, but if it's a real problem take it to a TV tech and explain the problem.

Neil

while monitors no longer have the analog controls that control the pincushion potentiometers on the circuitboard directly, pretty much every CRT with digital controls that I've seen over the years allow you to change the pincushion settings through the on-screen menu's.

Unfortunately, when I had a problem with my old Amiga monitor I couldn't find a TV tech willing to even take a look at a monitor, even though the amiga monitors pretty much were a TV minus the channel tuner back at the time. They would take straight SCART and composite video feeds.

Of course, with todays prices for new monitors, it really doesn't take much for it to be more economical to upgrade to a new monitor rather than paying someone to take a look at your current one. Just a 5 minute "Yup, it's broken alright" diagnosis would probably pay for half of a new monitor in the first place.

A CRT that's working badly enough that you would consider having looked at in the first place is just waiting for a new LCD screen to show up in the mail in my book. :-?

..thats why I stick with LCD monitors, and so far, its very nice..but its almost twice expensive than CRT with same diagonal...

PinCushion just seems to bow the edges in and out on mind and it looks straight right now. I guess if I made the edges fatter in the middle the circles would be round but then my screen edges wouldn't be straight, yuk.

Grey,

Yeas, that's right.

If you're seriously interested, there is a specific order in which you do the adjustments. I can't remember them right now, but I have them at home in a TV textbook. Let me know if you need the adjustment order; I know exactly where the book is (it's right next to Programming the Z80, by Rodnay Zacks), so it's no trouble.

Neil

cool, OK then as a matter of interest. thanks.