Search found 474 matches

by havok1919
Tue Jan 07, 2014 9:37 am
Forum: Hardware
Topic: Uzebox enters the matrix...take two!
Replies: 8
Views: 3731

Re: Uzebox enters the matrix...take two!

(Hey Alec!) :) The Microchip ENC28J60 is the 'common/cheap' SPI Ethernet chip out there. A search for that on eBay will turn up several, here's one: http://www.ebay.com/itm/ENC28J60-Ethernet-Board-ENC28J60-Controller-Board-LAN-Network-3-3V-for-MCU-AVR-/390729079781?pt=LH_DefaultDomain_0&hash=item5af...
by havok1919
Sun Jul 24, 2011 1:39 am
Forum: Programming & Software
Topic: chess4uzebox
Replies: 32
Views: 7754

Re: chess4uzebox

Just out of curiosity, have you ever looked in to how the old Atari 2600 (VCS) chess worked? (Just curious since that only had 128 bytes of RAM available, including representing the state of the board). Actually, that'd be fun-- I think the Uzebox should play the 2600 using their respective Chess so...
by havok1919
Tue May 31, 2011 10:49 pm
Forum: Hardware
Topic: Uzebox JAMMA
Replies: 233
Views: 92853

Re: Uzebox JAMMA

Ohh I see! Indeed you will need an output pin then. PD5 is good for me. I guess you'll need a relay or triac to drive your counter though. Arcade coin counters are typically +12V on the high side (sometimes +5V) and switched to ground. So a decent N-channel MOSFET will work fine. A protection diode...
by havok1919
Tue May 31, 2011 10:46 pm
Forum: Hardware
Topic: Uzebox JAMMA
Replies: 233
Views: 92853

Re: Uzebox JAMMA

Encoders ("spinners") can generate some really fast signals. I suspect that without some external hardware you'll have trouble keeping up with a raw quadrature encoder input in software with the rest of the Uzebox kernel stuff happening. (If you miss one clock edge you essentially lose the count dir...
by havok1919
Fri Jan 14, 2011 10:02 am
Forum: Hardware
Topic: Yet another future of uzebox+comparison of chips
Replies: 42
Views: 14030

Re: Yet another future of uzebox+comparison of chips

Should be interesting. ;-) You won't have any sort of buffer or power filtering, etc. so don't be surprised if you get a fair bit of noise and whatnot. An opamp buffer would probably be best (that way the AVR isn't sourcing the current for the full load of the TV and all the noise from the AVR CPU a...
by havok1919
Tue Jan 11, 2011 7:41 am
Forum: Hardware
Topic: Yet another future of uzebox+comparison of chips
Replies: 42
Views: 14030

Re: Yet another future of uzebox+comparison of chips

I would think (this is-- admittedly-- just off the top of my head) that you wouldn't really need much more than some resistors to make a little R2R type ladder (just like we do on the present generation Uzebox) with four bits for the luma level, then a single pin to output the chroma phase from the ...
by havok1919
Sun Jan 09, 2011 8:01 am
Forum: Hardware
Topic: Yet another future of uzebox+comparison of chips
Replies: 42
Views: 14030

Re: Yet another future of uzebox+comparison of chips

For greyscale you should be able to just disable the colorburst output and use luma bits only (no chroma phase to compare, so it should go black and white). I haven't thought to look to see how other systems do that... (ie, if the upper nibble is 0000 then that's the 'greyscale' map and you turn off...
by havok1919
Fri Jan 07, 2011 10:12 pm
Forum: Hardware
Topic: Yet another future of uzebox+comparison of chips
Replies: 42
Views: 14030

Re: Yet another future of uzebox+comparison of chips

To qualify my statement-- you *should* be able to get NTSC quality similar to an XGS (or Atari 2600, etc), but you probably want to switch things over to a native chroma/luma in that case. (ie, not RGB colorspace... it's the RGB->YC conversion that's tricky since the color gamut of those two don't m...
by havok1919
Wed Jan 05, 2011 8:37 am
Forum: Hardware
Topic: Yet another future of uzebox+comparison of chips
Replies: 42
Views: 14030

Re: Yet another future of uzebox+comparison of chips

Talk to me about the SDRAM on the external bus some time. I can make that happen really cheap. :) I've actually accumulated a fair bit of scrap from Mega644 overclocking issues on the AVCore. I've still not sold through the first batch of the AVCore's that I had built :oops: but I'm going to say it'...
by havok1919
Sat Dec 18, 2010 10:07 pm
Forum: Hardware
Topic: Yet another future of uzebox+comparison of chips
Replies: 42
Views: 14030

Re: Yet another future of uzebox+comparison of chips

Howdy everybody, Just making my semiannual appearance to see what's up. ;-) We've been using the Xmega32A4 on a gaming platform, so based on that experience smaller external SRAMs might not be totally useless. You can DMA from an SPI based SD card to memory with very little CPU overhead (interesting...