Search found 81 matches

by eteream
Thu May 16, 2013 11:33 pm
Forum: Sound
Topic: VGM or TFM with PCM?
Replies: 25
Views: 6618

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by eteream
Fri May 10, 2013 10:48 pm
Forum: Sound
Topic: VGM or TFM with PCM?
Replies: 25
Views: 6618

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by eteream
Tue May 07, 2013 7:44 pm
Forum: Sound
Topic: VGM or TFM with PCM?
Replies: 25
Views: 6618

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by eteream
Wed May 01, 2013 11:21 pm
Forum: Video Display Processor
Topic: Masking (hidding) priority sprites, how?
Replies: 6
Views: 2436

Masking (hidding) priority sprites, how?

Returning to old good times with some questions: I read on "Sega Genesis VDP documentation" by Charles MacDonald that you can hide (or mask) sprites putting one of them on x=0, then all the horizontal lines witch the sprite resides are masked and no other further sprite will be drawn on those lines....
by eteream
Wed May 25, 2011 11:01 pm
Forum: Megadrive/Genesis
Topic: Problems I find if I want to create a save state for real HW
Replies: 5
Views: 1719

Problems I find if I want to create a save state for real HW

So lets say that we have done a flash card, or something like it, that lives within the real hardware, and we want to implement a save state for any program or game like an emulator. Is it possible? What problems will we be facing? Obtaining the CPUs status seems not so much difficult, but how about...
by eteream
Mon May 23, 2011 5:56 pm
Forum: Hardware
Topic: 68000 micro-instructions documents?
Replies: 16
Views: 13083

In case there is a collision: http://img838.imageshack.us/img838/7316/mq68kalt.jpg As much as I can tell only shifts can overlap with fetch, but the fact is they wait 6 or 8 cycles to begin working. Now i'm facing Z80 design, so 68k will be stopped for a while. Now what I realize is CPUs are a lot s...
by eteream
Fri May 20, 2011 2:12 pm
Forum: Hardware
Topic: 68000 micro-instructions documents?
Replies: 16
Views: 13083

If you help me find which one micro/nano-instruction you need all the 3 units working altogether it will be very helpful.

May be you like this ones a little bit more:

Image
Image
by eteream
Sat May 14, 2011 7:33 pm
Forum: Hardware
Topic: 68000 micro-instructions documents?
Replies: 16
Views: 13083

That second patent really covers the internals. Of course, it comes from a time when patents were still valid inventions. You won't find anything close in a modern patent - the lawyers wouldn't stand for it. But that is a little hilarious, the idea is to prevent copying. Which defeats the whole pur...
by eteream
Thu May 12, 2011 6:28 pm
Forum: Hardware
Topic: 68000 micro-instructions documents?
Replies: 16
Views: 13083

You do not have enough M68KPM and M68KUM? Are these HLD dessigned CPUs? There is nothing about these words searching in Internet. I'm not aware of any documentation of what the 68000 does in each state. The closest I've seen is docs on how certain instructions "prefetch" the next instruction and ho...
by eteream
Tue May 03, 2011 10:17 pm
Forum: Hardware
Topic: 68000 micro-instructions documents?
Replies: 16
Views: 13083

68000 micro-instructions documents?

Is there a way to know what 68000 does exactly in every cycle? I mean, there are some things (PC++, decode instruction) that can be done not only in specific cycle but in 1 or 2 more. Take, for example the nop instruction, 4 cyles. Yon can do the PC:=PC+1 in the 3rd o 4th cycle. Same goes for the de...
by eteream
Tue May 03, 2011 9:31 pm
Forum: Hardware
Topic: HDD (or flash) instead of a CD, questions...
Replies: 140
Views: 34215

I read a bit of the implementation of the LC89510 and since it has his own memory, memory map and code, to replace it, we need a CPLD+RAM+ROM+PIC or, more simply, a FPGA. It looks easier to replace the CD drive and emulate the interface the LC8951 uses via a CPLD. As I see it: The CPLD to do the me...
by eteream
Sat Apr 30, 2011 1:03 pm
Forum: Hardware
Topic: HDD (or flash) instead of a CD, questions...
Replies: 140
Views: 34215

I read a bit of the implementation of the LC89510 and since it has his own memory, memory map and code, to replace it, we need a CPLD+RAM+ROM+PIC or, more simply, a FPGA. And, well, in a FPGA we can implement the whole MCD. So, as someone said, there is no point here. I dont understand why some say ...
by eteream
Fri Aug 27, 2010 9:19 pm
Forum: Hardware
Topic: HDD (or flash) instead of a CD, questions...
Replies: 140
Views: 34215

HDD (or flash) instead of a CD, questions...

I am wondering if this is possible:
1) physicaly attaching a HDD into SCD.
2) modifying the BIOS to access HDD instead CD while playing games.

The BIOS is the only code wich access to CD at low level?
or there are games that run CD directly? or do it all of
them?

Any other problem?
by eteream
Fri Aug 27, 2010 8:36 pm
Forum: Megadrive/Genesis
Topic: Found an interesting link - Accolade Vs Sega 1992 Law Case
Replies: 8
Views: 3014

Nagashima stated that it was possible either to create a game program which did not contain the TMSS code but would still operate on the Genesis III... That's easier: char strng[]={'S','E'-'S','G'-'E'-'S','A'-'G'-'E'-'S'}; aux = 0; for(i=0;i<4;i++) {aux+=strng[i]; tmss[i]=aux;} I don't know if this...
by eteream
Sun Apr 11, 2010 2:44 am
Forum: Megadrive/Genesis
Topic: SEGA game development tools ?SEGA MD5?
Replies: 3
Views: 2020

SEGA game development tools ?SEGA MD5?

I don't know if this is already known, but in case is not: http://www.hygraphics.com/products.htm (From the web page itself:) An obsolete tool, development tools, early SEGA MD5 SEGA MD5 development tools, including: Complete C compiler, compilation tools, libraries; (Note: the game is different fro...