Standard Pin Allocation: Open for Comments

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nubie
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Re: Standard Pin Allocation: Open for Comments

Post by nubie »

havok1919 wrote:
6845 wrote:I would like 2 have 2 psx controllers. My hint is to use a 6 I/O Port
5 signals for the psx controller, and 1 signal to switch this 5 signals to the 2nd pad.
if this is too complicated you could use a small pic cpu to map the 2 psx controlla to a 3 wire protocol .... (clk, data, strobe)
Like I said a couple posts up above, you can use two PSX controllers-- the second controller just needs its own select line. (I didn't want to go taking too many "free" lines on the AVR, so I didn't try to dedicate one, but if we stick to the "PORTA is controllers" idea then just use PA6 for the second controller select. All the other lines go to the PSX pads in parallel, no need to switch or mux anything.

The PSX protocol is really just about like four wire SPI anyway-- it has an 'ack' line added, but that's all.

-Clay
What about the 4-player adapter that Sony has? That uses one pad port and communicates with up to four pads.

I don't know how it works, but I am sure that there is documentation, or someone reading this knows how it works already.

Edit: Called the Multi-Tap $10 at Dealextrem.com: http://www.dealextreme.com/details.dx/sku.4207

In fact if making a console you could strip it for connectors as well.

Edit2: It may be more headache than it is worth. There is a PS1 multitap for $15 , and it is the official Sony one :) : http://www.baysoftgames.com/multitap1.html

I don't know as we would need more than 2 controllers anyway, unless we were making a 4-player Atari war clone. Or some kind of crazy 4 player pong or brick game. My brother wrote a game called "2D pong", and you moused out 2 axis per player, interesting.
6845
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Re: Standard Pin Allocation: Open for Comments

Post by 6845 »

Yes I´m an monochrom Videocontroller.
I do 80 chars per Line and with RA0-3 over an SRAM i could do GFX very well ;)

Here in Europe is psx more common than the nintendo stuff.
You can buy a PS2 Joypad and could use it on uzebox easy...
a snes pad to order via ebay from Hong kong is (maybe a copy then it´s much easier to cut in pieces to wire it on the box) is more complicated ;)


Clay, we should use your idea !

Cheers,
ladyada
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Re: Standard Pin Allocation: Open for Comments

Post by ladyada »

the standard pinout looks good to me. in order to make it easier to add whatever whack controller is desired, i brought out the 2 psx 'attn' pins and the 2 free pins and tied them to the NC on the NES controller. Were the NC pins on S/NES ever used for anything else? i dont remember but figured its worth asking
havok1919
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Re: Standard Pin Allocation: Open for Comments

Post by havok1919 »

ladyada wrote:the standard pinout looks good to me. in order to make it easier to add whatever whack controller is desired, i brought out the 2 psx 'attn' pins and the 2 free pins and tied them to the NC on the NES controller. Were the NC pins on S/NES ever used for anything else? i dont remember but figured its worth asking
I think those two pins were used for the Zapper/Superscope. Maybe the NES robot and god knows what other weird stuff. ;-) I know that they're not loaded on the SNES connectors from the Naki multitaps.

I put PSX connector solderpads down on the bottom of my board so that one of those could be loaded as an alternative to two SNES's. (makes things one-player for SNES, but based on the number of clocks to talk the PSX protocol and the width of those connectors I didn't see putting two down.)

-Clay
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uze6666
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Re: Standard Pin Allocation: Open for Comments

Post by uze6666 »

PSX controllers are nice at first sigh, but as I realized trying to implement them, they easily eat about 2 scanline each due to their awfully low clock rate (and that's just to read the basic status). In other words, they are not very Uzebox friendly IMHO. However, if someone puts some sort of bridge MCU between those to provide a SNES interface to the '644, I'd then gladly add special mapping code for those.

Cheers,

Uze
ladyada
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Re: Standard Pin Allocation: Open for Comments

Post by ladyada »

SInce PB4 is not taken for anything, im going to snag it for use as 'ad723 disable' for low power usage. i put a pullup on my board but it would be nice if the kernel set it to output high by default. during low power (sleepy) mode, drop the line low to reduce power suck.
havok1919
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Re: Standard Pin Allocation: Open for Comments

Post by havok1919 »

ladyada wrote:SInce PB4 is not taken for anything, im going to snag it for use as 'ad723 disable' for low power usage. i put a pullup on my board but it would be nice if the kernel set it to output high by default. during low power (sleepy) mode, drop the line low to reduce power suck.
I don't remember if we discussed that or if it was just coincidence, but that's how the option is on the AVCore as well. (I default to PB4 being available for GPIO, but if you want powerdown control on the AD723 you populate a resistor and open a little shunt on the PCB.)

-Clay
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uze6666
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Re: Standard Pin Allocation: Open for Comments

Post by uze6666 »

Speaking of pin assignment, I just realized a strange design decision on my part (to say the least) that will make it more complicated to optimize video cycles the way I intended. For some reason, I put the CSYNC output on PB0 instead of PD4 or PD5 (OC1A/OC1B), the pins related to the timer actually used for the NTSC timing. That would have allowed me to continually reprogram the timer to automatically toggle the pin instead of having to toggle it manually with empty loops just wasting precious cycles in between. That way I could have easily recovered about 8 scanlines per frame. That's about 14500 cycles.

Oh, well, I'll keep that in mind for the Uzebox 2 I guess! :D

-Alec
ladyada
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Re: Standard Pin Allocation: Open for Comments

Post by ladyada »

how about just tying PB0 to PD5? I can still do that. Is it something that can be changed with a #define?
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uze6666
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Re: Standard Pin Allocation: Open for Comments

Post by uze6666 »

how about just tying PB0 to PD5? I can still do that. Is it something that can be changed with a #define?
Yeah I guess we could, but Clay already has AVCore produced using PB0, so it will have to stay like this unfortunately :| . Anyway, although it will complexity the kernel a bit, I can achieve pretty much the same thing in software.

-Alec
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