Strange Bug in the ZX Spectrum Core

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Atmosfear
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Strange Bug in the ZX Spectrum Core

Postby Atmosfear » Wed Nov 16, 2016 3:08 pm

While checking the Spectrum TAP Games from the TOSEC Set to build a RomVault Dat, i was suprised that so many Games
wont run on the MiST (around 30%). And i discovered a curious Bug. Plenty of Games print on the Screen "Spectrum Play" instead of a character.
The ZX Spectrum does not have Hardware Sprites, usualy the Game modifies the Character Set and use this character as a software sprite. But the Spectrum also has Basic Keywords in his Character Set (Example: Print chr$ 254 would print "RETURN" on the Screen).
If you take a closer look at the beginning of the Game "Androide (1984)(ERE Informatique)(fr)[16K]" from the Tosec Set, which is a pacman clone, you see that pacman char is hunted from 4 times the word "Spectrum" rather than the 4 Ghosts !
The Spectrum Char Set does not have the Words SPECTRUM or PLAY in it, so where did they come from ?
First i checked the TAP Games on a Spectrum Emulator and they all work fine. But not only Sorgeligs Core is affected, also the very first ported Spectrum Core from Mike Stirling has this strange behaviour with the same games in CSW.
I checked then the Char Set with a little Basic Programm (10 FOR a=32 TO 255: PRINT CHRS a;: NEXT a) and did RUN it but everything was normal. So i can only think of a Bug in the z80 or in the spectrum.rom :shrug:

Some examples of affected Games:
A.T.F. (1988)(Digital Integration)
Academial Patience (19xx)(Tiger's Claw)
Alcatraz Harry 2 - The Doomsday Mission (1984)(Scorpio Gamesworld)
Androide (1984)(ERE Informatique)(fr)[16K]
Angler (1983)(Virgin Games)
Animated Strip Poker (1985)(Knightsoft)[a]
Antteroo the Mutant (1985)(Central Solutions)
Apocalypse (1983)(Red Shift)

Can someone please check a few of the listed Games on a ZX Uno ? I ordered one but it will take some time til i have it.

Thanks
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seedy1812
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Re: Strange Bug in the ZX Spectrum Core

Postby seedy1812 » Wed Nov 16, 2016 4:14 pm

The 128K version of the ZX spectrum lost some UDG characters to handle new keywords such as SPECTRUM ( 128K mode only ). Try running your games in 48K mode

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Re: Strange Bug in the ZX Spectrum Core

Postby Atmosfear » Wed Nov 16, 2016 5:02 pm

seedy1812 wrote:The 128K version of the ZX spectrum lost some UDG characters to handle new keywords such as SPECTRUM ( 128K mode only ). Try running your games in 48K mode


Bingo. Thats it. Switching Spectaculator Emu to 128k Model shows exactly the same behaviour as the MiST in 128k Mode.
But LOAD"" in 48k mode on the MiST gives an Tape Loading Error after the programm is loaded. :shrug:

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Re: Strange Bug in the ZX Spectrum Core

Postby Atmosfear » Wed Nov 16, 2016 9:31 pm

I tried now to manually load the games in 48K Basic with LOAD "" with sorgeligs ZX Spectrum Cores. Core 160622, Core 16027 and Core 160523 did load the Games and start normaly. But not the newest Core 160722. Loading the Games with LOAD"" from the 48K Basic always gives an Tape Loading Error after the programm is loaded. So if we want to run Games for the 16/48K Spectrum, we better switch to the Core 160627 until this is fixed.
Is it possible to bind multiple Key combinations to a joystick button ? it would be nice to be able to load Games with a Joystickbutton. Its kinda annoying to Press always the key combo J + (CTRL+SHIFT+P) + (CTRL+SHIFT+P) + ENTER to execute the LOAD"" command into the Spectrum Basic.

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Re: Strange Bug in the ZX Spectrum Core

Postby Sorgelig » Sat Jan 14, 2017 4:28 pm

Non-turbo tape loading has been fixed in 20170115 release.

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Re: Strange Bug in the ZX Spectrum Core

Postby Sorgelig » Sat Jan 14, 2017 4:54 pm

US(and many localized) keyboard has separate key " which is mapped to (CTRL+SHIFT+P). So you just press J + " + " + ENTER.

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Re: Strange Bug in the ZX Spectrum Core

Postby Atmosfear » Sat Jan 14, 2017 5:54 pm

Thanks alot for fixing the Bug :cheers:

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Re: Strange Bug in the ZX Spectrum Core

Postby Sorgelig » Sun Jan 15, 2017 12:41 pm

i'm testing macro LOAD "" by pressing F10 or after choosing the TAP from OSD.
F10 should be OK, while second one isn't clean way since can trigger unwanted input if TAP file has been chosen somewhere in the middle of game.

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Re: Strange Bug in the ZX Spectrum Core

Postby Sorgelig » Sun Jan 15, 2017 12:51 pm

By the way, you can choose TAP from OSD first, and only then type LOAD "" - it will trigger turbo loading which will load most games in couple of seconds.

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Re: Strange Bug in the ZX Spectrum Core

Postby Atmosfear » Sun Jan 15, 2017 11:57 pm

Nice, a Macro would be most helpfull.
BTW, i finished testing all 48K TAP games from the Tosec set. After cleaning the set from all Dupes there are 3511 working Games and only around 150 wont work. Most of them are Damaged TAPs so they also dont work on an Emu. Romvault DAT will be released once i finish testing Apps, Demos, Mags and so on. This will take some more weeks.
Overall we have now a compatibility around 98-99%. Thats impressive :thumbs:

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Re: Strange Bug in the ZX Spectrum Core

Postby Sorgelig » Mon Jan 16, 2017 2:17 am

what is Romvault DAT?

upd: nevermind. found the info.


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