Topic: Apple II

Hey, I just found these apple ii sources, maybe someone will find them useful. smile
http://www.cs.columbia.edu/~sedwards/apple2fpga/

2 (edited by PS4owns 2014-04-08 13:56:48)

Re: Apple II

Please please please can someone implement this into the FPGA Replay? Plllleease I want an apple ii core!!!

Re: Apple II

Me too, but first lets finish the C64 (much more challenging), then the Apple II is a piece of cake wink

/WoS

Re: Apple II

Hah, especially since the C64 is so badly explored into all possible and impossible details, that it must be perfect before one can be satisfied.

Remember those demos using tricks to determine whether the platform is an emulator or real hardware? Nowadays if you run Deus Ex Machina by Crest it says "Thank you for using a real C64" even if you are running VICE. What will it say on the Replay? smile

Anyway, this thread is about the Apple II. I like the "piece of cake" statement, wolfgang. That's the spirit. big_smile

Re: Apple II

Agreed!

Re: Apple II

Johey wrote:

Hah, especially since the C64 is so badly explored into all possible and impossible details, that it must be perfect before one can be satisfied.

You are right. Allow me to change the "finished" to "when it runs more than simple basic programs w/o crashing", otherwise I'll never start with the Apple  big_smile

/WoS

7 (edited by PS4owns 2014-04-14 02:27:54)

Re: Apple II

wolfgang wrote:
Johey wrote:

Hah, especially since the C64 is so badly explored into all possible and impossible details, that it must be perfect before one can be satisfied.

You are right. Allow me to change the "finished" to "when it runs more than simple basic programs w/o crashing", otherwise I'll never start with the Apple  big_smile


Please when you do start on the Apple II core version can you make it that only produces the images through the composite port? Reason behind that to get the full feel, quality and graphic output of the original Apple II it have to be through the composite port.  Otherwise, it will be DOS like, dull color and pixelated.  Can you also use the Apple //c core? Also, can the audio output come out from the audio out port jack? So when the Appl II makes that beep sound when you restart or turn it on...it comes out through the speaker of my PC through the audio jack?

Thanks!

Re: Apple II

You are free to use s-video if you like, but limiting to only that technology would be quite contra productive if you ask me. Many Replay boards (mine included) don't even have an s-video port.

Beside, you can connect any 15 kHz RGB monitor or tv to the DVI port with an appropriate cable or a stack of adapters.

Re: Apple II

Johey wrote:

You are free to use s-video if you like, but limiting to only that technology would be quite contra productive if you ask me. Many Replay boards (mine included) don't even have an s-video port.

Beside, you can connect any 15 kHz RGB monitor or tv to the DVI port with an appropriate cable or a stack of adapters.

I do not want to use s-video, I want to use composite port for Apple II core. I have one question to ask. Can I configure my soon to be fpga replay board to use composite port all the time (and be saved with this setting) when I enter apple ii core without having to manually tell it every time?

Re: Apple II

Ah ok. I misunderstood. Correct me if I am wrong, but as far as I know you cannot (or at least normally don't) disable any output. Everything is always fed to the DVI port as well as s-video and composite. In the config you set the video mode and if you set something out of specifications for the connected monitor, it will simply not show the picture.

In other words, you specify the display mode in the ini file for the Apple II core that you want 15 kHz and it will always start with picture on the composite port.

Re: Apple II

Johey wrote:

Ah ok. I misunderstood. Correct me if I am wrong, but as far as I know you cannot (or at least normally don't) disable any output. Everything is always fed to the DVI port as well as s-video and composite. In the config you set the video mode and if you set something out of specifications for the connected monitor, it will simply not show the picture.

In other words, you specify the display mode in the ini file for the Apple II core that you want 15 kHz and it will always start with picture on the composite port.

That is what I want then! big_smile I will do that ones Apple II core is completed!

Re: Apple II

Johey wrote:

You are free to use s-video if you like, but limiting to only that technology would be quite contra productive if you ask me. Many Replay boards (mine included) don't even have an s-video port.

Didn't the Apple ][ do some strange artifacting tricks on the composite to give the appearance of more colors? I seem to remember that from the old 8-bit Atari days, and thought they stole it from Apple. Anyway, those tricks didn't work on s-video or RGB.

13 (edited by PS4owns 2014-04-14 19:30:57)

Re: Apple II

amiga85 wrote:
Johey wrote:

You are free to use s-video if you like, but limiting to only that technology would be quite contra productive if you ask me. Many Replay boards (mine included) don't even have an s-video port.

Didn't the Apple ][ do some strange artifacting tricks on the composite to give the appearance of more colors? I seem to remember that from the old 8-bit Atari days, and thought they stole it from Apple. Anyway, those tricks didn't work on s-video or RGB.


That is what I am saying here! Apple II ...ESPECIALLY APPLE II AND VERY SPECIFICALLY APPLE II should only output image through composite. This system is DESIGNED ALL IT'S HARDWARE system for the composite output...any other means and you ruined the entire atmosphere!  Anyone who owns FPGA Replay with just DVI and uses Apple II core they are not getting the full experience of this core and they are really missing out on the system!!

Curious...can a person use real Apple II disk drive on the FPG Replay Arcade to run their games? Such as this disk drive: http://www.vectronicsappleworld.com/col … mage2.jpg?

Re: Apple II

You will probably find what-ever trick we need to pull digitally to reproduce this affect, will also work fine on the other outputs ...

Re: Apple II

MikeJ wrote:

You will probably find what-ever trick we need to pull digitally to reproduce this affect, will also work fine on the other outputs ...

MikeJ, if you can mimic the bad and horrible graphical output of the composite of the apple ii on a crt old tv on other output then ALL THE BETTER and it will be great!!!

16 (edited by JimDrew 2014-04-14 22:03:11)

Re: Apple II

That's called NSTC (never the same color).  The Apple ][ video driver had interested issues with making white, where greens and purples were the byproduct of the phase shifting.  That should be easy enough to re-produce.

Re: Apple II

JimDrew wrote:

That's called NSTC (never the same color).  The Apple ][ video driver had interested issues with making white, where greens and purples were the byproduct of the phase shifting.  That should be easy enough to re-produce.

Sweet!! If you guys could mimic all the errors and defects of the apple ii color system and ntsc like the original apple ii THAT WOULD BE SWEET big_smile

18 (edited by foft 2014-06-09 10:58:22)

Re: Apple II

An Apple II GS would be great! I'm not aware of a decent 65816 or Ensoniq doc in vhdl or verilog...

19

Re: Apple II

That's called NSTC (never the same color).

artefacting isnt really related to NTSC per se... the apple2 dot clock is a multiple of the color carrier (which again is a sideeffect of deriving everything from a single clock), meaning you can create certain colors by displaying certain patterns of hires pixels (and it only works in composite, since thats the only way the color decoder "sees" said hires pixels). the same technique was used eg with CGA display adapters (via composite). computers released some time later fixed this unwanted effect by choosing a dotclock that isnt a multiple of the color carrier (thats why artefacting doesnt work anymore on eg the C64)

to simulate this effect digitally, basically look for those specific patterns, and then apply the respective color (fake version, some emulators do this) or even build a rudimentary analog video encoder/decoder datapath (might be preferred on fpga, and would make it very easy to simulate other CRT effects as well). there is this X11 screensaver called "oldtv" that does a lot of this stuff in software, if you want to take a look. not exactly trivial to understand though (due to speed optimizations mostly)

20 (edited by PS4owns 2014-06-10 04:08:06)

Re: Apple II

gpz wrote:

That's called NSTC (never the same color).

artefacting isnt really related to NTSC per se... the apple2 dot clock is a multiple of the color carrier (which again is a sideeffect of deriving everything from a single clock), meaning you can create certain colors by displaying certain patterns of hires pixels (and it only works in composite, since thats the only way the color decoder "sees" said hires pixels). the same technique was used eg with CGA display adapters (via composite). computers released some time later fixed this unwanted effect by choosing a dotclock that isnt a multiple of the color carrier (thats why artefacting doesnt work anymore on eg the C64)

to simulate this effect digitally, basically look for those specific patterns, and then apply the respective color (fake version, some emulators do this) or even build a rudimentary analog video encoder/decoder datapath (might be preferred on fpga, and would make it very easy to simulate other CRT effects as well). there is this X11 screensaver called "oldtv" that does a lot of this stuff in software, if you want to take a look. not exactly trivial to understand though (due to speed optimizations mostly)

Actually this primitive color system and bugs and horrible composite quality of the Apple II in how it displays images and colors means a GREAT DEAL lot to me. I need this system implemented as much as people would like to have Super AGA X 2 with 1 GB CHIP RAM for Amiga, for example. So yeah, please implement the SAME EXACT way the Apple II output image into the core....

it not only brings me back to the good old nostalgia days...but it is SOOOOOOOOOOOOOOOOooooo calming to play games on the Apple II. I find Apple II a whitenoise computer, same as people who would like to turn their air conditioner ON to sleep on the night. That is how I look at Apple II.

21

Re: Apple II

Actually this primitive color system and bugs and horrible composite quality of the Apple II in how it displays images and colors means a GREAT DEAL lot to me.

i feel very much the same about the C64 video output (and put a great deal of effort into researching the details and add them to VICE). for the apple2 its perhaps even more important, as some games extensively use this artefacting stuff and just look horrible when looking at the plain bitmaps.

22 (edited by PS4owns 2014-06-11 00:45:13)

Re: Apple II

gpz wrote:

Actually this primitive color system and bugs and horrible composite quality of the Apple II in how it displays images and colors means a GREAT DEAL lot to me.

i feel very much the same about the C64 video output (and put a great deal of effort into researching the details and add them to VICE). for the apple2 its perhaps even more important, as some games extensively use this artefacting stuff and just look horrible when looking at the plain bitmaps.

Yes. Call me crazy by the way, but when I receive the FPGA Arcade Replay I am going to put an apple ii logo (the color apple with the half bite on it) right above the composite port, to indicate, that for my case anyways, it is to be used only for the Apple II core. The s-video/dvi/etc will be used for the rest of the system. I just feel that with the physical actual hardware of the composite's primitive system added to MikeJ implementing the "emulation" of how Apple II produces video output+Composite port+CRT TV will bring the quality of the Apple II back to normal as if I am using real Apple II computer.

23

Re: Apple II

I haven't studied Mike's circuit for the composite output (I suspect there are filters that causes problems), but if you want to play, I guess you can make a VGA(DVI-A) to composite/svhs adapter plug and do all the composite modulation digitally..

24

Re: Apple II

Composite out is directly generated by an encoder from the sync+RGB signals, which are also used for VGA out (plus a color burst signal from the PLL is needed). Assuming the board is equipped with it (as it is an assembly option).

See also here: http://www.fpgaarcade.com/punbb/viewtop … 2778#p2778

/WoS