Apple II games ideal candidates for some conversions?

[www.atarimania.com]

With a number of games released on the Atari being ports, I'm surprised nobody is venturing in Apple territory. Wouldn't some Apple II software be perfect for quite straightforward conversions? Note that I'm not even talking about arcade titles. There are some great "static" programs on the platform that would deserve a translation to the Atari: adventures, strategy games and (gasp) even educational stuff.

 

I know there were a couple of attempts some ten years ago but nothing since. Could it just be lack of interest for non-arcade titles? Technical difficulties I may be missing? 

Edited October 30, 2019 by www.atarimania.com

[emkay]

You know that AppleII graphics is very unique as it uses 7 bits for the graphics? This makes "straight forward" conversions almost impossible. 

Could be possible to adapt still images, but as soon as there are parts of the graphics were part of the game mechanics, everything has to be rewritten. Chosing any software from other platforms where just a byte is to cut out  to have working graphics available. 

The "one bit" changes can end in a strange mess. 

 

[adam242]

47 minutes ago, emkay said:

You know that AppleII graphics is very unique as it uses 7 bits for the graphics? This makes "straight forward" conversions almost impossible. 

Could be possible to adapt still images, but as soon as there are parts of the graphics were part of the game mechanics, everything has to be rewritten. Chosing any software from other platforms where just a byte is to cut out  to have working graphics available. 

The "one bit" changes can end in a strange mess. 

 

 

XXL's Apple Invaders conversion from 2010 shows this effect... the weird stripes in the graphics.

 

[Rybags]

Much of our earlier 3rd party catalog was Apple II originals, e.g. Crossfire, Apple Panic, Jawbreaker/2, Choplifter, Lode Runner, David's Midnight Magic (and other pinballs), Drol, and Karateka (though somewhat later).

 

As mentioned the graphics differences make it a right pain to convert accurately, there is probably no other computer in existence that used the pixel pairing methodology to either have hires or multicolour mode as they did.

And many games worth having already were or have subsequently been converted.

 

Of course the absolute pinnacle would be Prince of Persia, possibly followed by the Sierra Kings Quest and Leisure Suit Larry games though in some cases it'd probably be easier to use another platform's (like C64) version as the base.

[+playermissile]

The advantage of an Apple II port over other (more advanced!) machines like the C64 is that the Apple has very little specialized hardware. By setting up the Atari display list to mimic the Apple's unusual layout and accounting for things like reading the keyboard and handling disk access, virtually all of the original code from the Apple version can be used unchanged. The graphics will have to be edited, because the bit pattern is backwards within each byte (resulting in left-to-right mirroring within each byte), as well as bit 7 being used as a palette bit rather than a graphics bit (resulting in the striped graphics like Apple Invaders above).

 

If you're interested in more detail, I had a discussion with @Shamus about his conversion of the Apple II game Sabotage in the podcast: http://playermissile.com/podcast/ep006.html

[Heaven/TQA]

Apple should be not that hard... simple additional apple2atari table lookup for the bitmap data... no big deal and we are faster for compensation.

[Gunstar]

1 hour ago, playermissile said:

as well as bit 7 being used as a palette bit rather than a graphics bit (resulting in the striped graphics like Apple Invaders above).

 

If you're interested in more detail, I had a discussion with @Shamus about his conversion of the Apple II game Sabotage in the podcast: http://playermissile.com/podcast/ep006.html

So I'm a bit confused. Is it 7-bit with the 7th being palette, so that graphics bits are actually 6-bit, or is it 7-bit graphics bits with the 8th being for palette? 

Edited October 31, 2019 by Gunstar

[+playermissile]

1 hour ago, Gunstar said:

So I'm a bit confused. Is it 7-bit with the 7th being palette, so that graphics bits are actually 6-bit, or is it 7-bit graphics bits with the 8th being for palette? 

Sorry for the confusion. Bit 7 counting from zero, so bits 0 - 6 are graphics and bit 7 selects the palette.

 

To confuse things even further, what bit 7 really does is, if it's set, is to cause a one-half pixel shift for the pixels in this byte. Apple II hi-res graphics is drawn on a 560x192 grid where each pixel in the 280x192 normal resolution takes two horizontal grid spaces, so bits 0 - 6 determine 14 grid spaces representing 7 pixels. Setting bit 7 moves the pixels one grid space to the right, i.e. half a pixel. This generates the different "palette" by creating different artifacting colors.

 

It's even more complicated than that, so here's a really great description of hi-res graphics:

 

https://www.xtof.info/blog/?p=768

[www.atarimania.com]

Yes, I'm aware of all the games we had from the Apple back in the day and the XXL conversions - though I forgot about the more recent SABOTAGE, thanks for reminding us of that one! - but my emphasis was more on all the excellent titles which relied less on heavy graphics or animation.

 

How about all the adventure games like Masquerade or Alpine Encounter? Maybe even all-text programs like Rambo - First Blood - Part II? There are also some great strategy / simulation games from the mid to late eighties that the Atari never got. Also, for some reason, I really dig some of the educational software that exists on the Apple. 

Edited October 31, 2019 by www.atarimania.com

[Gunstar]

21 minutes ago, playermissile said:

Sorry for the confusion. Bit 7 counting from zero, so bits 0 - 6 are graphics and bit 7 selects the palette.

 

To confuse things even further, what bit 7 really does is, if it's set, is to cause a one-half pixel shift for the pixels in this byte. Apple II hi-res graphics is drawn on a 560x192 grid where each pixel in the 280x192 normal resolution takes two horizontal grid spaces, so bits 0 - 6 determine 14 grid spaces representing 7 pixels. Setting bit 7 moves the pixels one grid space to the right, i.e. half a pixel. This generates the different "palette" by creating different artifacting colors.

 

It's even more complicated than that, so here's a really great description of hi-res graphics:

 

https://www.xtof.info/blog/?p=768

Actually the further explanation makes it more understandable for me, comparing to tricks used on Atari's with half-pixels shifts, like in some software GTIA/Antic mixed modes for higher perceived resolution, etc. and from years of experience with Graphics 0 or 8 on the Atari, and making the most from NTSC color artifacting. For example, IIRC, there is a Graphic 0/8 art program called [The?]Graphics Master on Atari that has a bunch of ready made color patterns which allows about 8-9, IIRC, different artifacting colors on screen at once, similar to Apple II's though the artifact colors are achieved differently with the half-pixel shift in Apple, where as on Atari it's due to odd/even pixels creating color and/or skipping odd-even pixels to create colors and other unique pixel mixing by manipulation of pixel positioning. Obviously the Atari artifact colors are restricted more by requiring adjacent pixels to create new colors.

Edited October 31, 2019 by Gunstar

[carlsson]

Perhaps an European system like the BBC Micro or at least the Acorn Electron - which has a surprisingly large library once you start digging - would be better candidates? I suppose the Oric (which also has a decent library for its market impact, though smaller than the Electron) might be ruled out due to its 6x8 characters.

 

Now, if 6502 to 6502 conversion between different systems really is that easy, I honestly don't know.

[Lord Thag]

Well, I'm no hardware expert on porting things to the Atari, but the fact there is a working (if quite slow) Apple II *emulator* that runs on the Atari makes me think Apple II ports are certainly doable. I know it's due to the Apple running most things via processor without specialized hardware etc. Without modification, and Atari can't handle 80 column mode, hi res etc. but many games could (and were) be ported back in the day.

Atari Apple II Emulator post

[www.atarimania.com]

Yes, I was thinking of this very emulator as well and am surprised it didn't quite catch on.

 

You could probably consider the BBC Micro or Acorn Electron for some arcade or action games - I know there are very nice titles - but I have doubts about all the other genres compared to what exists on the Apple.

 

[Gunstar]

26 minutes ago, www.atarimania.com said:

Yes, I was thinking of this very emulator as well and am surprised it didn't quite catch on.

 

You could probably consider the BBC Micro or Acorn Electron for some arcade or action games - I know there are very nice titles - but I have doubts about all the other genres compared to what exists on the Apple.

 

I have the Apple II emulator downloaded and ready to go, as well as the one for the Spectrum, but I was under the impression that they required the Rapidus accelerator board which I don't have yet. And possibly the reason it hasn't caught on? If it works without the Rapidus, I'll use it for some adventure/RPG games not on the Atari. I don't mind if Balder's Gate or something runs slow.

Edited October 31, 2019 by Gunstar

[carlsson]

Ok, I don't know about strategy games but certainly in particular the Beeb (but also Electron) had a lot of educational software, aimed at UK children.

 

Link to Electron games: http://www.acornelectron.co.uk/profs/electron/top_lvl.html

 

Not sure which is the best BBC Micro archive. This one says complete but seems to lack both a list of publishers and categories, making it extra hard to navigate. This one at least order games by publisher, like the Electron site does.

 

Edit: Ok, by clicking around I made this link to games which primarily are of the strategy type.

Edited October 31, 2019 by carlsson

[www.atarimania.com]

Apart from The Sentinel, the Apple II trounces the BBC when it comes to strategy / simulation / adventure / educational games as it has all the big American titles. Deeper, more complex, just no comparison.

 

[carlsson]

Sure, though everytime the Apple II games library is discussed I get the feeling people exaggerate a lot both when it comes to library size and quality. A number of years ago elsewhere on AA there was a discussion about combing together the definitive Apple Gamebase and how many thousands of games it would contain. From the already existing efforts online, some quite elaborate work done, the total library perhaps was 1/10, at most 1/5 of what people claimed it ought to be.

 

Also I suppose all the big American titles on the Apple are those which never were ported to the Atari 8-bit in the first place?

 

But yes, if 7 pixels per byte is an issue when converting code and graphics, it would require most of the great games to be ported to be in some text mode that is easier to convert, or a lot of rewrite is in order. From that perspective, perhaps porting Commodore 64/16 and Acorn BBC/Electron (not to mention the recompilation of Z80 to 6502 which allows for various ZX Spectrum and perhaps Amstrad CPC, MSX etc ports) is a little less work even if the library is not the same.

[Gunstar]

IIRC, most of the modern home-brew ports we have gotten are from the C64, BBC micro and Spectrum. In fact, I'd been intending to get all three of those computers in recent years, but all the great ports we've seen from the three has diluted my desire in obtaining them by now. (not to mention Apple and Spectrum emulators)

Edited October 31, 2019 by Gunstar

[www.atarimania.com]

55 minutes ago, carlsson said:

Also I suppose all the big American titles on the Apple are those which never were ported to the Atari 8-bit in the first place?

 

Yes, I'm mainly referring to all the Sir-Tech, Origin Systems, Bantam, SSI, MECC, Mindscape, Broderbund Software, Sierra... titles we never got. There are tons of them.

 

Edited October 31, 2019 by www.atarimania.com

[+Faicuai]

2 hours ago, carlsson said:

Perhaps an European system like the BBC Micro or at least the Acorn Electron - which has a surprisingly large library once you start digging - would be better candidates? I suppose the Oric (which also has a decent library for its market impact, though smaller than the Electron) might be ruled out due to its 6x8 characters.

 

Now, if 6502 to 6502 conversion between different systems really is that easy, I honestly don't know.

 

I would have to agree with this one.... Just look at Hobgoblin, ported from BBC (which looks and feels just better, overall). A great piece of work, without a doubt:

 

 

 

Edited October 31, 2019 by Faicuai

[www.atarimania.com]

1 hour ago, carlsson said:

Sure, though everytime the Apple II games library is discussed I get the feeling people exaggerate a lot both when it comes to library size and quality. A number of years ago elsewhere on AA there was a discussion about combing together the definitive Apple Gamebase and how many thousands of games it would contain. From the already existing efforts online, some quite elaborate work done, the total library perhaps was 1/10, at most 1/5 of what people claimed it ought to be.

 

I guess it depends what is counted. There's likely less arcade software on the Apple but thousands of educational software titles that are almost never mentioned as there is almost no information online (GB64 doesn't separate them from the rest on the Commodore 64 so I believe they can be included).

 

For instance, if you take R. R. Bowker's Software for Schools - 1987-88, there's an index at the beginning with lists of what's available by subject. The Atari section is 18 pages, the Commodore PET / 64 / VIC-20 is 46 pages and the Apple II a whopping... 150! Not all of it is great but it's generally better than what we have.

 

As for the other titles, from time to time, I'd love to be able to play a game of The Ancient Art of War, Might and Magic, Wasteland, Alter Ego, 2400 AD, Moebius...  

 

 

Edited October 31, 2019 by www.atarimania.com

[carlsson]

Wow, that is indeed amazing. I'm afraid the search functions both on the forum and through Google are too weak in order to dig out the other thread posted a number of years ago, so I can't tell if people who talk about the giant Apple II library actually expect and include a gazllion of educational programs in those numbers. Possibly they've heard a total number somewhere, but don't know for sure that number include all those titles.

[Lord Thag]

Yeah most of what I would want to play from the Apple II library falls under the strategy & or RPG labels. Because of the great disk drive & popularity in schools, the Apple got a LOT of that stuff that the Atari did not... all things I'd love to see ported. SSI, EA and Origin in particular had a lot of great stuff the Atari never got. Wizardry, Bard's Tale etc.

[Shamus]

On 10/31/2019 at 11:18 AM, www.atarimania.com said:

Yes, I'm aware of all the games we had from the Apple back in the day and the XXL conversions - though I forgot about the more recent SABOTAGE, thanks for reminding us of that one! - but my emphasis was more on all the excellent titles which relied less on heavy graphics or animation.

 

How about all the adventure games like Masquerade or Alpine Encounter? Maybe even all-text programs like Rambo - First Blood - Part II? There are also some great strategy / simulation games from the mid to late eighties that the Atari never got. Also, for some reason, I really dig some of the educational software that exists on the Apple. 

Sabotage is really, really old (it was converted in the mid-80s or so)!    Converting Apple II software shouldn't present too much of a problem, especially if it's single loader stuff that lives in 48K (like Sabotage).  The Apple's larger disk size is also a consideration when doing a conversion, but again, not fatal.  Things would start to get tricky with software that requires 64K or more, as obviously memory mapping has to be dealt with; also things like double hi-res, 80-columns, paddles, etc.  In retrospect, maybe it would have been easier to port Bard's Tale I-III from the Apple ports as opposed to the Commodore ports...  It would be nice to have a port of Ultima IV with music (why, WHY Origin did you omit the music???), a port of Ultima V...  Hmm...

 

At any rate, yes, doing conversions from the Apple II should be imminently doable, as it didn't have much in the way of custom graphics and sound hardware (like the Commodore had); though it takes a pretty good understanding of the internals of not only the Apple II, but the Atari as well!    If anyone wants to do a port, I'd be more than happy to share my expertise.

[www.atarimania.com]

That would be fantastic. Of course, the coders would need to be convinced about the enterprise first

 

BTW, I really like the 4 am cracks. Maybe a number of titles are not doable because of the double hi-res or other things but there are many neat titles in the collection: https://archive.org/details/apple_ii_library_4am

Edited November 3, 2019 by www.atarimania.com