Amiga questions you've always been too embarrassed to ask

[Toni Wilen]

Originally Posted by StingRay

What I never understood was why the CLI window, upon booting Workbench in PAL-World, defaulted to the NTSC size... even though you could drag it to PAL size. It took someone to make a (very popular) CLI command to put in the startup-sequence that would resize the window automatically.

KS 1.x has hardcoded console window open string: CON:0/0/640/200/AmigaDOS (Fixed/improved in 2.x)

As far as I remember (and I may be wrong) this was caused by a bug in Kickstart's PAL/NTSC detection routines, sometimes the window was opened in full PAL mode.

This is different bug. It makes extra PAL area completely inaccessible.

[lordofchaos]

I have a question. Who is "Fungus The Bogeyman"?

[xArtx]

Originally Posted by lordofchaos

I have a question. Who is "Fungus The Bogeyman"?

Colin Dooley (an Amiga programmer) ???

[tesla]

One explanation of the difference in weight would be one is analog, (has a heavy transformer) and the other is switching, digital and much lighter.

I've never seen the inside of either, so just guessing.

[lordofchaos]

Originally Posted by xArtx

Colin Dooley (an Amiga programmer) ???

Hmmmm, interesting. Sounds plausible.

Originally Posted by tesla

One explanation of the difference in weight would be one is analog, (has a heavy transformer) and the other is switching, digital and much lighter.

I've never seen the inside of either, so just guessing.

It's gold I tells ya, it's all gold! Well maybe not, never looked myslef..

[demolition]

Back in the C64 days, I had a teacher in school who told us that the reason the transformers were so heavy was because they filled them with asphalt.. I have yet to see one like that, but then again he did tell a lot of stories and not all of them equally true.

[Mrs Beanbag]

Originally Posted by demolition

Back in the C64 days, I had a teacher in school who told us that the reason the transformers were so heavy was because they filled them with asphalt.. I have yet to see one like that, but then again he did tell a lot of stories and not all of them equally true.

Um transformers are heavy because the main part is made of solid* iron, and has to be quite big if you need it to transform a lot of power at mains frequency.

The big transformers you see on power lines are immersed in a vat of oil to distribute the heat evenly.

*laminated

[s2325]

Maybe they are heavy on Earth but not on Cybertron

[demolition]

Originally Posted by s2325

Maybe they are heavy on Earth but not on Cybertron

If Cybertron would have lower gravity, your muscles would probably be equally weaker if you grew up there, so it might feel just as heavy?

[XimeR]

Originally Posted by mikrucio

Here is one i have never been able to work out!

90% of all Amiga Games are PAL
yet they do not cover a full 320x240 screen.
most games only cover a typical 320x200 screen.
So the game typically only fill 3/4 of a monitor screen...

Is it because most game devs were from USA?
ITS BUGGING ME!

Back in 1990, people were writing to CU Amiga with the same question....

[Retro1234]

Originally Posted by XimeR

Back in 1990, people were writing to CU Amiga with the same question....

Just the reply to that reminds me of the good old commodore monitor you could stretch the vertical & horizontal so most games filled the whole screen

[xArtx]

Originally Posted by Boo Boo

Just the reply to that reminds me of the good old commodore monitor you could stretch the vertical & horizontal so most games filled the whole screen

Now I'm reminded too... and it did a good job of it
the controls that move the picture around had far greater range than other monitors.

[alenppc]

Originally Posted by Mark Wright

For example: in PAL-World, load up a disk with one of those 50/60Hz bootblock toggles, switch to 60Hz, then swap the disk for Super Hang On. The game now fills the screen and is ST speed. With scanlines, but that was arcade-authentic back then...

Well, those "scanlines" are present in PAL mode as well, except they are much closer together so they are a lot less noticable. In NTSC-land all CRT TVs look like that, even for broadcasts.

Not all PAL monitors supported the 60Hz stretching mode however. It varied model by model. I know that some C= 1084s would do it but not others. Some would centre the picture and divide the extra black bars between the top and the bottom.

Conversely, the original C= A1080 NTSC monitor could be stretched to display almost the full 50Hz picture (around 320x240ish) so it could still be used for PAL gaming. Virtually none of the CRT NTSC TV sets, however, would display a 50Hz picture. They would just display a rolling screen, and this is still valid for a lot of modern LCDs as well (black screen when fed with 50Hz signal).

[Zak]

The PAL and NTSC issue:

in 90´s I had an Amiga 1200 with Q-Drive CD-Rom. I also had a CD 32 version of "UFO Enemy Unknown". I remember I tried to get it working on my A1200 with CD 32 emulation (was in the Q-Drive drivers pack), but the screen was flickering and rolling on PAL TV. When I took out the NTSC file from the screenmode-drawer on my A1200 hard-disk, it suddenly worked.

What I want to point to is, that it maybe doesn´t take much change to make a 320x200 PAL game be a 320x200 NTSC game. I also have had a CD 32 game where you could switch PAL / NTSC in-game while the computer was running. I think it was Street Fighter 2 Turbo (on real CD 32), but I am not quite sure at the moment.

Am I totally wrong? Isn´t it, that a 320x200 program could be changed from PAL to NTSC just by changing system-configuration files? Or did I misinterpret what happened?

If I am right, you could use 320x200 images for both PAL and NTSC, you certainly couldn´t make a 320x256 game be an NTSC one.

[Mrs Beanbag]

Originally Posted by Zak

Am I totally wrong? Isn´t it, that a 320x200 program could be changed from PAL to NTSC just by changing system-configuration files? Or did I misinterpret what happened?

If I am right, you could use 320x200 images for both PAL and NTSC, you certainly couldn´t make a 320x256 game be an NTSC one.

There is a hardware register starting in ECS that you can set a bit to switch between 50Hz and 60Hz.

[diablothe2nd]

what's the maximum resolution image an unexpanded A1200 can EIGHT WAY scroll and still have enough ram left for a few bobs/sprites and gameplay? i'm thinking top down racers, shooters etc (think Overdrive, Micro Machines, Chaos Engine, Total Carnage etc)

[Mrs Beanbag]

Originally Posted by diablothe2nd

what's the maximum resolution image an unexpanded A1200 can EIGHT WAY scroll and still have enough ram left for a few bobs/sprites and gameplay? i'm thinking top down racers, shooters etc (think Overdrive, Micro Machines, Chaos Engine, Total Carnage etc)

Well I managed 320x224 with room to spare, going up to 320x448 interlace mode shouldn't even increase the overhead. No reason 640x512 shouldn't be possible. But I've never seen arcade-style games in other than low-res.

[diablothe2nd]

thanks for the response Mrs B, but i was referring to the scrolling image and not the screen resolution. any ideas?

[Mrs Beanbag]

On AmigaDOS you can change current directory just by entering a path at the prompt. I just wondered what happens if you have a directory called "cd" and you type "cd". Well the good news is that doesn't get confused.

[Mrs Beanbag]

Originally Posted by diablothe2nd

thanks for the response Mrs B, but i was referring to the scrolling image and not the screen resolution. any ideas?

Oh you mean if you have one single, pre-rendered background? Usually scrolling games use a tile-based map and a physical screen only a bit larger than the visible area to hide the redrawing at the edges.

For a double buffered screen in 16 colours you could just about fit a 1300x1300 playing area into Chip RAM but that wouldn't leave much room for anything else, maybe 100k or so for your bobs/sprites. I wouldn't recommend trying to push the boundaries of Chip RAM if you want your game to run from Workbench though because you can't guarantee how much is already used up.