Compressed Pictures

By Dave E

Originally published in EUG #56

With the superb new pictures on The Joseph Lavery Collection PD disk doing the rounds on the Elk websites (plus the recent release of ROTAM), 2001 looks all set to be the Year Of The Electron Slideshow. To add to these picture collections, you'll find this EUG features also features a selection of images - these from the archives of the defunct Elk PD library.

They are stored in a compressed format and called up with a very easy utility (also on the disk) *SCRLOAD. You may also find its companion code *SCRSAVE to be of use in saving some of your uncompressed pictures in a compressed format.

A loader program retrieves each screen file in turn (with *SCRLOAD). The code automatically sets the right mode and palette and the two routines save a lot of space; nearly twice as many pictures can be saved on a disk compared with the *LOAD/*SAVE commands! Note though that you should really be in Mode 0, 1 or 2 if you use *SCRLOAD in one of your own programs as it doesn't change BASIC's HIMEM pseudo-variable (0, 1 and 2 all take the same amount of memory). Plus the screens take a bit longer to load in as they have to be 'decompressed'.

A much bigger selection of pictures was available at one time through the (now closed) PD library Electron PD (and, without the efforts of EUG reader Ross Little, they would probably have been lost for all time by now). However, the original slideshow was marred by lots of blurred, "digitised" pictures of television programs which were not worthy of inclusion in EUG, or per se. This slideshow is compiled of all the better 'freehand' drawings and loops continuously until its viewer presses ESCAPE.

You'll note the first images are of Amstrad memorablia. These were created by Greg Heslington on an Amstrad CPC 464 with AMX Art. Most of the authors of the others have chosen to remain annonymous. Here's hoping they haven't been published elsewhere on coverdisks!

EUG #56