Back to sprites

Here is something more that I was not aware of. Mode 4 sprites often have a mask. So what is the difference between an alpha channel and a mask. I thought an alpha channel gives 256 shades of transparency while a mask only says this bit of the image is visible and this bit is not. Wrong apparently. While writing a bit of code to save a mode 4 sprite with a mask I discovered this translation in the mask:


Image Pixel ---> Mask Pixel ---> Visible pixel
white ---> white ---> white
white ---> black ---> black
red ---> black ---> green
green ---> black ---> red
black ---> black ---> transparent

Only those bits of the image where both the visible and mask pixels are transparent.

Crazy Ideas

I discovered today that with GWASS you need to have a version of smsq/e running before you can compile a more up to date version of smsq/e. In other words smsq/e is not freeware for self compilers! Is this what was intended in the licence? Shades of the microsoft world! This reminds me of a situation when I wanted to upgrade an older PC to an internet workstation by adding a PCI wireless card to connect to my broadband modem router. The PC from "PC world" was installed with release 1 of Windows XP. I had service pack 2 on CD from a magazine to upgrade the XP installation. Could I get the software for the wireless card to install and work. No way, until in frustration I connected the PC via an ethernet cable to the modem. Suddenly a raft of further windows upgrades down loaded and installed. Card now worked. Catch 22 - when upgrading a PC to add a wireless network card you need to have the latest version of windows installed. To have the latest version of windows installed you need an internet connection. To have an internet connection you need a wireless network card installed. To get the installed card to work you need the latest version of windows etc.

Anyway it seems smsq/e is now up with the big boys.

Finally here are some crazy ideas ; lets connect a microdrive to a Qx0 through a serial port. Why? Don't you have old software on mdv cartridges still. Or is there anyway to put SBASIC asleep on a key without a button being visible in the button frame?

Absolutely finally, what is the single most influential program in QL Heaven that has transformed the QL World? Answers on a postcard for discussion next post.

Another Secret

I expect every one knows this but me. I have been examining the format of mode 4 sprites. Why you say. Because I don't have a clear written description of it, even although the format was set 20+ years ago. Anyway to my surprise the line width of the sprite regardless of the visible pixel width seems to be a multiple of 4 bytes every time. Even a 7 pixel wide sprite in 4 colours which uses 2 bits to map each of the 4 colours available per pixels has a minimum line width in bytes of 4 not 2.

Why I wonder. Its a bit costly in memory in a system that was memory lite - 128k in a black box QL with about 96k available once the system had been loaded. In fact memory was so tight that some applications used the screen memory as a work area when processing data.

Anyway memory is no longer an issue. I wonder if this apparent profligate use of memory has allowed the Window Manager to be adapted to use 24 bit sprites although only 16 bit colours can be displayed.

I wonder.

Abandonware

One thing that surprises us here at QL Heaven is the fact that there are still "commercial" programs in the QL World that were written not just one or two years ago but decades ago. For example Text87plus 4 a quirky word processor is still a commercial program at a price of around £80. Who in their right mind would want to pay that premium price for an unsupported program. The author is no longer on the QL scene, does not develop software for the QL any more but will not relinquish the "commerciality" of his program. The last updates to make his program run on modern systems were done by the author of QPC2 and sold as a commercial program although there were bugs in that as well.




Other authors have been more pragmatic. Psion has allowed the free distribution of its seminal office suite both in the standalone formats and as Xchange, yet retains its ownership. I think Psion have also allowed the free copying of other software such as its famous chess program.



I can understand why someone producing new software may expect a financial reward at least initially after it is launched and while support is being provided. Examples of this are Launchpad and QPC2 both of which are currently supported.



The QL scene is littered with examples of abandoned commercial software where authors have declined to provide support yet still expect to be paid for each copy of their software in existence, even if it has to be patched by another authors program to run on existing QL systems.

It seems that new spurious copyright claims are being exploited as a means of gold mining enthusiasts. An example of this is the sale of the SMSQ/E O/S on Quo Vadis Design at £37.20. The O/S has not been significantly updated for 2 years. The previous 5 years of updating has been done by enthusiasts for free, not the original author. The O/S can be obtained for free on the original sources site (http://www.scp-paulet-lenerz.com/smsqe/) with all the necessary tools to compile and run the latest version for any QL system. Under the licence a token payment was required for distributors - this was 10 euros, even at today's exchange rate there is no way that 10 euros equates to £37.20



Authors should be required by law to demonstrate continuing copyright bt the provision of continuing support otherwise programs must be re licenced as abandonware.

Quanta news material

Dilwyn Jones, Quanta news editor is seeking QL news items for the Quanta magazine. Happy to pass on any info.

QL activity on the web

At the moment there are 7 QLs for sale on ebay, on auction with starting prices from 0.99p to £125-00 for buy it now. There seems to be a lot of QL interest although QL users, Quanta and QLToday all now seem quiescent. I recall reading in one of the QL magazines that Jan Jones book was now unobtainable. Have a looks at :

http://www.speccy.org/sinclairql/archivo/docs/docs.htm

Someone has been busy. Legal or not there is Jan Jones book amongst others in .pdf format.