About Gfxs Modes and DLIs during loading

[José Pereira]

I know this was talked many times but I really never understand it.

I know it's possible but with some tricks (rules...).

And I remember about this when I saw the video and the loading process with of new XXL's game Mazezam.

XXL has the Top and bottom using GR.7 and Middle credits letters probably in GR.15. Then it has to setup a DLI to change the Gfxs Mode.

 

To have those loading screens during loading the guys in the back days doing the loading pictures in Bitmap Modes 4colours only because to have (normally) it at the same time as loading tape or disc you can't put there DLIs.

-> In char-Modes they would have minimum 3Lines = 1charset and then to change charset you would need to use a DLI.

-> Today with the G2F we could set PMGs underlays but the same PM must have all screen high same width, xPos, colour because if we change one of these we have to use DLI(s).

 

From the poast I remember that there are games that have different lines with different Gfxs Modes during loading.

Right now I remember U.K. tape version of International karate that (like XXL's game) change the Gfxs Mode across screen:

-> Top: GR.1 "International Karate"

-> Middle: GR.0 Keyboard controls

-> Bottom: GR.2 Loading counting

 

And if I think in this a little it's even more strange as I would have 3charsets in 3Modes or are the same charset numbers but set into three different Gfxs Modes across the screen?

 

But there still DLIs to change the Gfxs Modes, right?

 

 

 

So, what can we have or not during a loading process?

Can it be possible to have ANTIC4 colourfull screen with PMGs underlays?

(It seems it isn't because even today, the recent games like, for example, Bomb Jack or Yie Ar Kung Fu show the Loading screen and it disappear and only after that the game continues the loading process)

[Heaven/TQA]

difficult because SIO (interrupts talking to disc drives) are interferring with the DLIs. and with many different devices I would go for G2F-title screen and switch it off while loading. it is better anyway to have more RAM.

 

but you can use G2F and using underlays without DLIs so that's possible.

[Creature XL]

Look the loading picture of MJO the black lines are there becaus eof DLIs.

As the DLI can be missed when a POKEY IRQ is running, I have put the same DLI a 2nd time in the next line (the blank scan line).

This idea is from Stefan Dorndorf and in my case it doesn't destroy the picture a lot.

There might be better solutions, however, they are all worthless. As nowadays everybody preferres hi-speed loading and then it is even more difficult to do it right.

For example, load MJO with normal SIO and you see a nice color-cycle effect in the "Loadynk..." with hi-speed you do not see it, as it seems to skip the VBI's.

 

If there are indeed solutions, I would be welcome to hear them

 

EDIT: typos

 

What Heaven said. G2F with one charset and fixed positioned PMG is possible and might be the most useful with all loading methods.

 

BTW, I even put a 3 second in it, so that emulator see the laodin gpic (and animation). Mor specific, teh main program only starts if the loading pic was displayed for 3 seconds. So, normal users do not have to wait longer

Edited September 3, 2012 by Creature XL

[Rybags]

Minimal screen is even better for IDE devices, can mean 10-20K / second or so difference in speed.

 

What to do ? My suggestion would be to have a timed section.

 

e.g. start of file, set RTCLOK to zeros. Then have another 2K or so of the game/demo load, and work out the data flow rate. If it's more than about 3K per second and less than 20K, then chances are 99% that a sensitive high-speed SIO is being used.

 

In this case, disable any fancy loading screens.

 

Over 20K, we're probably talking to an IDE device and interrupts don't bother it. Also give the user the ability to disable the fancy loader screen by keypress.

[+JAC!]

>So, what can we have or not during a loading process?

In fact you can have everything provided, it does not jam the CPU for too long in one go. You can even have multiply DLIs during loading provided they are fast (no WSYNC, change onld 1-2 registers) and provided you can do what CreatureXL has described to prevent "dropping out" during IO.

>Then it has to setup a DLI to change the Gfxs Mode.

You don't need DLIs for this, this is just the DL.

 

Example: DL

- empty lines

- first section

- single line+DLI1: change color register1/charset

- single line+DLI1: change color register1/charset (DLI repeat)

- second section

- single line+DLI2: change color register1/charset

- single line+DLI2: change color register1/charset (DLI repeat)

...

 

[Tezz]

Jose, it's pretty straight forward as Jac says to do all of the above, with vbi music players and even sample playback. I was part way through writing a disk loader with a long dli last year just for the sake of doing it as it's only possible at standard sio speed. Not much use these days with modern storage devices.