BREAKER.BAS - PD Screen capture utility from 1987

[ComSoft6128]

BREAKER.BAS by Alistair Scott - from the WACCI PD library.

In this short video I use Breaker to take a screenshot of the 1986 commercial program "The Electric Lantern Show"
Saved files could then be used by the Advanced Art Studio, MicroDesign Plus or any of the other art/graphic packages available for the CPC.

Sequence:
1: Breaker is activated at 0:50
2. The Electric Lantern show is then RUN
3. Screenshot taken at 1:30 and saved to disc/6128 Plus resets
4. DES is used to show saved file on disc
5. Saved file is then displayed using the Vidi ROM

https://www.youtube.com/watch?v=jIk8RZZREOE

Links:
http://www.cpcwiki.eu/forum/applications/the-electric-lantern-show/

https://www.cpcwiki.eu/index.php/WACCI

https://www.cpc-power.com/index.php?page=staff&lenom=Alastair%20SCOTT

https://www.cpc-power.com/index.php?page=detail&num=9973

LISTing for BREAKER is shown in the fifth video of this thread:
http://www.cpcwiki.eu/forum/applications/small-pd-graphic-display-files/

[Gryzor]

How did this work? I'm guessing it would break/be incompatible with quite a few programs?

[ComSoft6128]

Hi Gryzor,

Not being a programmer I can only speculate that it lurks in a rarely used area of memory ( somewhere in the 2nd 64K?) waiting for activation but if anyone wants to check this the LISTing for the program is the fifth video in the thread below, @AMSDOS has already made some comments but I would be interested in anything else that is found.

http://www.cpcwiki.eu/forum/applications/small-pd-graphic-display-files/

[AMSDOS]

BREAKER.BAS by Alistair Scott - from the WACCI PD library.

That explains why I couldn't find it in AA 

How did this work? I'm guessing it would break/be incompatible with quite a few programs?

I think the video explains the process better than me explaining. Any program which turns off Interrupts wouldn't work with this utility, but a lot of the early AMSOFT games might, usually a good way to tell is if CTRL+SHIFT+ESC initiates a Soft Reset back to BASIC, then this Utility may work. With a lot of the modern games, you cannot CTRL+SHIFT+ESC to Soft Reset the Computer - forcing you to switch it off.

Hi Gryzor,

Not being a programmer I can only speculate that it lurks in a rarely used area of memory ( somewhere in the 2nd 64K?) waiting for activation but if anyone wants to check this the LISTing for the program is the fifth video in the thread below, @AMSDOS has already made some comments but I would be interested in anything else that is found.

http://www.cpcwiki.eu/forum/applications/small-pd-graphic-display-files/

BREAKER.BAS works within the Main 64k of the computer, it has just managed to find a couple of areas high in memory to reside. The &AF00 area is reserved usually for Stack Use (storing and retriving values from PUSH/POP statements in assembly), but the area itself has so much space allocated to it, people have put their code there instead, at least I think that is what that area is. The other one &BE80 I'm not sure about, unlike the other it's above the Firmware, but just below Screen Memory (&C000..&FFFF), placing code there works, because as I recall people had used that region for writing Cheats for games, I'd also seen people use &BE00, though between &BE00 and &BE80 there is a spot which if altered crashes the computer I think.