Loading screen displays into QPC2

Discussion and advice about emulating the QL on other machines.
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Martin_Head
Aurora
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Joined: Tue Dec 17, 2013 1:17 pm

Loading screen displays into QPC2

Post by Martin_Head »

I am having problems loading mode 4, 32K screen dumps into QPC2.

I set QPC2 to QL Colours, and the screen resolution to 512x256

Enter QPC_QLSCREMU 4 To set the screen address to 131072 ($20000) and mode 4

Then LBYTES filename,131072

The screen that loads is garbled

This happens in Versions 4.02 and 4.04. However Version 3.30 loads the screen OK, as does Qemulator.

Has anyone else seen this problem? Could someone else try it, in case there is something weird at my end.


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tofro
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Re: Loading screen displays into QPC2

Post by tofro »

Martin,

just tried with this file:

http://www.dilwyn.me.uk/docs/manuals/qimi_pic.zip

(remove the _pic header first)

loaded into a QL-coloured QPC 4.02 with QPC_QLSCREMU 4 activated.

Worked fine.

Tobias


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mk79
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Re: Loading screen displays into QPC2

Post by mk79 »

Martin_Head wrote:I am having problems loading mode 4, 32K screen dumps into QPC2.

I set QPC2 to QL Colours, and the screen resolution to 512x256

Enter QPC_QLSCREMU 4 To set the screen address to 131072 ($20000) and mode 4
Not sure why you're experiencing problems here, just wanted to say that the screen address will automatically be $20000 when you set the display to 512x256 with 4 colours. QPC_QLSCREMU is for overlaying the original QL screen onto a higher resolution or colour screen. In the end the feature didn't work out as well as I thought because this is a one way street, only things drawn in the $20000 area will be copied to the bigger or higher colour display area, not the other way round, and when a legacy app mixes direct screen access with legitimate graphics calls it doesn't work so good. In your case (loading a complete file) it should be fine however.

Marcel


Martin_Head
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Re: Loading screen displays into QPC2

Post by Martin_Head »

I will experiment a bit more with it.
I am trying to get an old QL program to run in QPC2. Which loads in a pre-rendered screen display, and has its own screen drawing routines.
So I wanted to make sure that the display file was at $20000, and in mode 4

One of the several attempts to load on version 4, did load correctly. I don't know if I did something different, or if it was by pure chance.


Martin_Head
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Joined: Tue Dec 17, 2013 1:17 pm

Re: Loading screen displays into QPC2

Post by Martin_Head »

I have done a bit more investigating. And I get the same problem even if I don't use the QPC_QLSCREMU command.

So that you know where I am starting from. I am using Windows XP, and a 720K floppy disk with QPC2 versions 4.02 & 4.04

The problem seems to be with floppy disk accesses. If I copy the screen dumps from the floppy disk I am using to DOS3_, and then LBYTES from there. The screens load OK. Except in QPC2 version 4.04, where they load OK but the cursor does not return, and the emulator hangs.

In my Windows 8 laptop (which only has V4.02 loaded) I get the same. Load from floppy disk, garbage on screen, Load from DOS3_ OK.

In another PC running Windows XP and QPC2 V4.02. The same problem.

However on my main system, if I copy the screen dumps from the 720K floppy to a 1.4M floppy then, in V4.02 the screen loads OK from the 1.4M floppy. I even had the 1.4M floppy in FLP1 and the 720K floppy in FLP2. When I loaded from flp1_, OK. Load from flp2_ garbage.

But In V4.04 both disks showed the same problem again.


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