November 1, 2013

zxsp 0.8.0pre21: misc. old stuff

Hi Folks,

bad news: i can't make up my mind for a picture. A blog post without a photo? – wait – there will be one, at the end of the post, maybe. :-)

New in this version:

misc. old stuff

"misc." consists of the following:

Video Beam Indicator

Yeah! Finally, the video beam indicator is back again. Right now only for the color machines, but the b&w machines know exactly where the beam currently is anyway. ;-)

The video beam indicator is a red&yellow blinking cursor at the current position of the video beam. It is activated when the cpu clock is throttled down to 100 kHz or less or when you single step in the debugger. This is an aid for anybody who wants to write a demo with some critical timing. For those who only want to play games it's a "nice to have" for curiosity. B-)

Load assembler source

Now it's possible (again) to load snapshots and tapes from assembler source. The source will be compiled by the built-in zasm assembler and the resulting snapshot will be loaded as if it was initially selected to load. The source file is stored in the "recent files" list so that reloading it is easy.

It's not trivial to get the headers of .sna or .z80 files right, so i have included template files in this distribution.

Supported target file types for assembler sources are .sna, .z80, .ace, .rom and .tap.

Load .rom and .scr files

Also, it is now possible again to load .rom and .scr files. 

Load .rom files: Based on the rom size, the currently running machine and the default machine in the preferences, the application choses the best fitting machine and uses this to load the rom file. If am Interface 2 or a SPECTRA interface is attached, then 16K roms will load as a rom cartridge. Else they will replace the built-in rom.

Load scr files: If the current machine is a color machine, then the .scr screenshot is loaded into the currently displayed video ram of that machine. Else, based on the default machine in the preferences, a color machine is chosen and started, but probably the screenshot will not be displayed very long in this case. 

Load .tap and .dsk files

Tapes and disks can now be loaded like a snapshot. zxsp choses the best fitting machine based on the file type, the currently running machine and the default model in the preferences. Note: a tape or disk normally does not contain any easily retrievable information about the required machine, so you should select the desired machine before loading a tape or disk.

Load .dsk files: That's fairly easy, as these disk files can only be loaded into a ZX Spectrum +3. zxsp just tries to select the British or Spanish version based on the currently running machine and the default model, if the currently running machine is not a +3.

Load .tap files: These tape files can only be loaded into a color model or into the Jupiter Ace. zxsp tries to detect whether this is a Jupiter Ace tape and loads it into a Jupiter Ace, else it uses the currently running machine, if it is a color model, else it tries to determine the best model based on the default model, starts it and loads the .tap file. Most .tap files can be instant-loaded entirely, giving the impression of loading a snapshot. If the program uses it's own tape loader code, instant loading does not work and you have to wait until the tape is loaded. You may open the tape recorder window (if it isn't opened by default) and wind back and fore if required.

Load .tzx files: These tapes may be loaded into every model. zxsp can't tell beforehand which might be the best fitting one. So it loads a .tzx file always into the current machine. You should always start the desired machine before loading a .tzx file. Frequently .tzx files contain programs which use custom loaders. Then instant loading will not work and you have to wait for the game loading as normal.

Loading a tape like a snapshot vs. inserting a tape into the tape recorder
Tapes and disks are no snapshots. They contain the data of their respective represented media. When you double-click or open a tape or disk file with "open file", then zxsp secretly loads a snapshot which was saved at a point where it started to load a program from tape or disk and inserts the requested tape or disk into the respective drive. Additionally, it sets the tape recorder to instant-load. The result is, that it looks like zxsp is loading the tape or disk like a snapshot, though you now know it isn't.

This is a convenience feature, though. Normally you should launch the desired model, insert the tape into the tape recorder (or the disk into the disk drive) and type LOAD "" or similar. Then you get back more of the original feeling. You can select instant-load and auto-start-stop the tape here as well.

Load .tap files into the Jupiter Ace
You may not know it, but the Jupiter Ace had no load tape command with wildcard and it had no auto-start feature. So zxsp takes some effort to supply the tape loader snapshot with the required name. But it does not know which command is required to start the game or to load subsequent data blocks. Once the first dictionary is loaded you are alone. You may open the tape recorder and wind the tape fore and back to see the names of following blocks, but you'll have to pick the info on how to load them and how to start the game from it's documentation.

Display parameters for the b&w Ulas

I reworked the display of video parameters in the Ula inspector for all models, but especially the b&w models, which up to now just showed some default values collected from various sources in the net. They now show the actually used display parameters, though some, most notably the cpu cycles per scan line, still just show the nominal values.

Select 50 Hz or 60 Hz model for the TK clones

I have added a 50 Hz / 60 Hz switch to the Brazilian TK models. I'm not sure about the cpu clock for the color 50 Hz models. If someone owns a TK85, TK90X or TK95 could he please determine the model (50 vs 60) and tell me the quartz frequencies? 


Fixed a problem with the .ace files saved by zxsp. 
The two final bytes were missing and made them not load. :-|

Fixed spurious crash when switching between models.
This was annoying me for a long time now and i really thought it was Qt to blame. But it was my fault and the error only popped up at an unexpected place, misleading me for quite a while. Under certain race conditions a mutex was released twice and then another thread waiting for this thread to terminate crashed in it's wait position, somewhere deep in the library function. :-/ 
Actually this fix made me issue version pre21 today.


An image, an image ...

.ace sample program loaded from assembler source animated gif file made with zxsp

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