Conference rusure::nintendo

    Re .0:
    
    A lot of the concepts resemble other 6502-based systems such as the
    Atari 400/800 and Commodore VIC-20/C=64.  I'd make a few assumptions
    based upon my knowledge of the C=64.
    
>   The display is a "character-graphics" display.  It consists of 32
>   characters by 32 characters (I'm not sure about the exact resolution of
>   a character).
    
    The best resolution one could expect on an NTSC television signal is
    somewhere around 320x200.  If the screen is made up of 32 character
    cells across by 32 cells high, each cell would be 10x6 pixels. 
    Commodore uses cells which are 8x8 to provide 25 line of 40 characters.
    Note that the ability to do smooth scrolling requires at least one
    additional character cell in each dimension (in memory, at least).
    
>   There is a second 2K RAM chip used by the CRT controller (PPU) to
>   contain "sprite" (floating character???) information, as well as the
>   1024 characters for the screen display.
    
    Yes, a sprite is a floating object.  Its size doesn't necessarily have
    anything to do with the size of character cells.  (The C=64 has 7
    sprites, each of which is 24x21 pixels.)  I presume that Mario and each
    of his foes is a sprite.  If (like the C=64) sprites can be made
    double-height and/or double-width, game designers have a fair amount
    of flexibility.  Look at the busiest game to figure out how many
    sprites might have been implemented.

	Hi,

	This year's summer vacation entails a car trip from
	Colorado to Oregon, thru southern Wyoming and Idaho,
	northern Utah and eastern Oregon: "The Stinking Desert!!!"

	Since I have two NES addicts for passengers (5 and 8
	yrs) I pose the following question:
	
	Has anybody played with making the NES battery powered?

	Since most all of the chips are cmos this seems "doable".
	(assuming the proper DealWithAbles...8�)

				   Stra...

    Get a power converter from Radio Shack....
    
    It converts 12VDC to 120VAC.  At least you can use the outlet for
    other things after the trip.
    
    Dave
    

	Take a look at the AC adapter. If it specifies a DC voltage, then
	you can get a battery holder and some parts from Radio Shack to
	make a battery pack and cable. I think 9 volts is probably
	about right, but check the voltage on the AC adapter first. Use D
	cells, not a 9 volt transistor radio battery.

	If it is AC, which it probably is, you would have to modify the
	game itself by adding a connector that is hooked up after the
	diodes (or bridge) that converts the AC to DC. and use the above 
	mentioned battery pack.

	The above assumes that the internal power supply for the NES consists
	of a simple DC regulator. If they use the AC for something such as 
	a clock interrupt, then you can't run off DC.

	You do have a battery operated TV I trust?

Larry

	Thanks for the ideas!

	No offense Dave, but the power inverter doesn't "turn me on" in the
    proposed environment.  If I decide to take a Sony XBR along I may
    consider it.  :^)

	Larry,
	If the AC adapter is 9 VAC output (which it is) then what would it
    matter if I applied DC to the input? The only hazard I could foresee
    would be if the power supply designer selected bridge diodes with a
    lower average current then the rated supply current (1.5 A).  If the
    P.S. is a half-wave type then this won't be a problem, right?

	By the way, the NES uses an internally generated 4 Mhz clock for
    all it's timing functions, and I do have a battery/auto/ac powered 5
    inch TV that is just big enough to see "things" on.  Any advice on
    automotive power conditioning?

				    Kelly

>	If the AC adapter is 9 VAC output (which it is) then what would it
>    matter if I applied DC to the input? The only hazard I could foresee
>    would be if the power supply designer selected bridge diodes with a
>    lower average current then the rated supply current (1.5 A).  If the
>    P.S. is a half-wave type then this won't be a problem, right?



	True. The only thing that might cause a problem is the .6V or so
	drop through the diode(s). If it's a bridge, you'll only get about
	7.8V with 9V in. If the unit just uses a 7805 regulator, 7.8V
	will be adequate.

	13.8V from a car battery with the engine running would probably blow
	the NES up from the heat generated by the voltage differential. You 
	could build a pre-regulator using an LM317 with a nice heat sink and
	set it up for 9V.

	One other thing, these days most everything digital runs on 5V. Just 
	in case though, open the NES up first just to make sure it doen't have
	a transformer in side for �12V or some such.

Larry

Some info from Usenet about the NES controllers - Stapes
========================================================================
From ryn!decvax!decwrl!ucbvax!hplabs!hp-pcd!hpcvlx!everett
						Thu Sep 22 09:46:36 EDT 1988
Article 1004 of rec.games.video:
>From: [email protected] (Everett Kaser)
Subject: Re: Nintendo joystick pinouts?
Date: 20 Sep 88 18:51:19 GMT
Organization: Hewlett-Packard Co., Corvallis, OR, USA

The Nintendo joystick is not a "passive" joystick, ie. just switches.  It
also contains a parallel-load/serial-shift-out chip, that encodes the eight
switches in the joystick, and shift them out on a single line.  Most other
games/computers use a parallel interface to the joystick.  (If you notice,
the Nintendo joystick connector only has 7 pins.  To do a parallel interface
would require 9 pins, one for ground and one each for each of the switches.
Since the Nintendo joystick uses only one line for serial data in, one for
the out-going LOAD signal to the chip in the joystick, one for ground, one
for +5, and one for clock (for clocking the serial bits), that leaves two
other lines that are unused by the standard joysticks.  I'm pretty sure
they're used by the light-gun, but not positive, since I don't own a light
gun.)

Everett Kaser

    
    I have one of my controlers bad the only part inside it is a D-4021-B
    Shift Register CMOS device. I will like to repair it the only problem
    is that I can't find the part here on P.R. so I will apreciate any
    help, If someone knows were I can order it send me the address and
    price quote.
    Send me a direct mail to TROPIC::LVARGAS.
    Thanks in advance.