ANTIC decap and reverse engineering

[+Larry]

If Antic ever does get modeled in an FPGA, would it be possible to add an 80 column text mode?  The XEP80-II is great, but not having to have an external device would be better IMO.

[reifsnyderb]

11 minutes ago, Larry said:

If Antic ever does get modeled in an FPGA, would it be possible to add an 80 column text mode?  The XEP80-II is great, but not having to have an external device would be better IMO.

An 80 column text mode would be awesome.  However, it's interesting to note that the Atari could already do 80 columns if graphics 8 were to be used with a special character set.  

 

 

[foft]

I almost made antic on a chip. I went to sillyventure in 2018 equipped to have a 600xl with all the chips replaced by fpga. In the end they all worked ok except antic. That needed more work since the version I made for the de1 didn’t play well with real halt/phi2. Anyway that antic recreation still exists almost unchanged in de1, mist, mister, chameleon etc. 
I didn’t really attempt it since then, though have some of the boards if anyone wants a go.

As for 80 col, I did 2x and 4x colour clock modes on the fpga platforms but no-one is interested enough to try it. In theory antic and gtia could be replaced together in a system to do something similar, though of course really faster memory is also needed.

[+Larry]

3 hours ago, reifsnyderb said:

An 80 column text mode would be awesome.  However, it's interesting to note that the Atari could already do 80 columns if graphics 8 were to be used with a special character set.  

 

 

But those 3-bit characters look a bit strange, at least to me.  Most of the software 80-column things are also slow, especially when moving around lots of lines, as in a word processor.  The exception that I know of is ACE80.  It is the fastest I've used.  Another work-around is the SDX 64 column utility.  Nicer looking text and speedy, too. From drac030, I believe.  

[+Stephen]

Yeah - the various software tricks are OK but  true 640 pixel hardware driven mode is the only way to go these days.  It's a real shame the VBXE didn't take off like I hopes it would.

[phaeron]

ANTIC doesn't have enough bandwidth in or out to do an 80 column text mode the way that regular 40 column mode works. There isn't enough memory bandwidth on the input side to read the character names and font data, or enough bandwidth on the AN0-AN2 bus to push the data to GTIA even if it could accept 640 resolution graphics. It's hard to get around this without coming up with a solution that doesn't look like VBXE or at least SOPHIA as ANTIC alone just can't do it.

 

[Piotr D. Kaczorowski]

Very interesting topic. I'm joining and will be watching 👀