Author
| About GEM
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Imanok
msx addict
Posts: 284 |  Posted: September 30 2003, 11:27 |
As Gem is SR5 based and due to the few colours used by the GameBoy, I just wondered... why don't the creators try to use SR4 instead of SR5??... I suppose that this would improve the emulator speed a lot!!
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GuyveR800
msx guru
Posts: 3048 | Posted: September 30 2003, 14:33 |
Gameboy displays 4 colors per 8x8 block. SR4 only displays 2 colors. Picture quality would degrade massively. Also, hardware sprites must be used when working with SR4 because using software sprites is HORRIBLY SLOW and has the same color-problem. Gameboy sprites can display 3 colors per line, while SR4 sprites only 1. There are 10 sprites per line on gameboy, on SR4 only 8.
See the problem? 
You can test an experimental hardware-sprite renderer in GEM since a few versions ago, and while faster, it sucks beyond words. |
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NYYRIKKI
msx master
Posts: 1528 | Posted: September 30 2003, 16:06 |
I still get Incorrect DOS version error with COMMAND.COM 2.41 + IDE (Yes, I've set the EXPERT mode on)
Do you have any idea, what could cause this?
Another question is, how could I make a "correct " DOS2 program, that would not complain about MSX-DOS version, if expert mode is off?
~NYYRIKKI
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Latok
msx master
Posts: 1734 | Posted: September 30 2003, 16:08 |
Are you sure this posting belongs in this GEM-thread? Please post it in the correct thread and I'll delete this one  |
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NYYRIKKI
msx master
Posts: 1528 | Posted: September 30 2003, 16:21 |
The problem is in the GEM code...
~NYYRIKKI
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GuyveR800
msx guru
Posts: 3048 | Posted: September 30 2003, 16:31 |
Wrong version of MSX-DOS error message in GEM is shown when either:
- EXTBIO is not available
- No mapper support in EXTBIO is available
- Pages 0-3 are not mapped to mapper segments 3-0
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GuyveR800
msx guru
Posts: 3048 | Posted: September 30 2003, 16:32 |
Quote:
| Another question is, how could I make a "correct " DOS2 program, that would not complain about MSX-DOS version, if expert mode is off?
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Use a MSX-DOS2 formatted floppy |
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NYYRIKKI
msx master
Posts: 1528 | Posted: September 30 2003, 16:54 |
Quote:
| Wrong version of MSX-DOS error message in GEM is shown when either:
- EXTBIO is not available
- No mapper support in EXTBIO is available
- Pages 0-3 are not mapped to mapper segments 3-0
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There must be something wrong as all these requirements are met. Could you test it with COMMAND2.41? I've compiled my own version of it, but this problem was there long before sources were available and I think, that I tried GEM version 0.6 back then.
~NYYRIKKI |
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NYYRIKKI
msx master
Posts: 1528 | Posted: September 30 2003, 17:03 |
Quote:
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Use a MSX-DOS2 formatted floppy
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That was a way too easy solution.
~NYYRIKKI |
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Imanok
msx addict
Posts: 284 | Posted: September 30 2003, 18:02 |
Quote:
| Gameboy displays 4 colors per 8x8 block. SR4 only displays 2 colors. Picture quality would degrade massively. Also, hardware sprites must be used when working with SR4 because using software sprites is HORRIBLY SLOW and has the same color-problem. Gameboy sprites can display 3 colors per line, while SR4 sprites only 1. There are 10 sprites per line on gameboy, on SR4 only 8.
See the problem?
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Now I see it... i didn't know how the GB works
It's a pity... |
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NYYRIKKI
msx master
Posts: 1528 | Posted: October 06 2003, 17:30 |
Today I had a little time to figure out, what's the problem with GEM on my HD.
When you use GET_PH routine the DOS does simple IN A,(#FX) and does not mask upper bits to zero. Now, when you compare the page number, you will get NZ flag set and that will cause the incorrect DOS version to be displayed. I removed the check from my version and now everything works just fine.
So... it is not a problem of your code. Anyway the error check is not perfect as it will not restore the CPU as the CPU mode is not yet detected.
~NYYRIKKI
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NYYRIKKI
msx master
Posts: 1528 | Posted: October 06 2003, 17:33 |
I meant... the problem is, that I have MAP2.COM in my AUTOEXEC.BAT
~NYYRIKKI |
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GuyveR800
msx guru
Posts: 3048 | Posted: October 06 2003, 17:52 |
Quote:
| I meant... the problem is, that I have MAP2.COM in my AUTOEXEC.BAT
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Good, glad that's settled
Quote:
| So... it is not a problem of your code. Anyway the error check is not perfect as it will not restore the CPU as the CPU mode is not yet detected.
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Dude, quit disassembling my code! 
Thanks for pointing that out, I moved the CPU mode check/change to right after the DOS1 check now. Who knows, maybe I'll release a GEM v0.9 someday |
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Grauw
msx professional
Posts: 1006 | Posted: October 06 2003, 20:01 |
Quote:
| >>Use a MSX-DOS2 formatted floppy <<
That was a way too easy solution.
~NYYRIKKI
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DOS2 includes the tool 'fixdisk', which can make disks DOS2-format without erasing the contents.
~Grauw |
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NYYRIKKI
msx master
Posts: 1528 | Posted: October 07 2003, 01:23 |
Quote:
| Dude, quit disassembling my code!
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I'll promice, that I will not talk about your code anywhere again. You are still so amazing with your "dynamic recompilation", that you can't make me stop looking your binarys with SUPER-X
Actually I just opened a new conversation at www.msx.org/forumtopicl1475.html ... that is quite a close to this topic.
~NYYRIKKI |
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