FS1

[ClausB]

FS1 was released by subLogic for Apple II and TRS-80 some years before their famous FS2. Has FS1 ever been ported to the Atari?

 

I just finished porting it to the Exidy Sorcerer from the TRS-80. I say finished because I didn't start it. Someone else did a port but left the display badly squashed into half the screen height. That's because TRS-80 displays 16 lines where Sorcerer does 30. Both can do block graphics of 3 vertical pixels per line. So I adapted the port to use full screen height and get better vertical resolution to boot.

 

Anyway, that experience got me somewhat familiar with the FS1 code, so I'd like to try the Atari port. Any interest?

Edited February 13, 2022 by ClausB

[ClausB]

 

Edited February 13, 2022 by ClausB

[_The Doctor__]

It would be interesting, it might even perform well on the Atari

[+eebuckeye]

Impressive.. where do you have information on the Exidy port?

[Keatah]

I'd love to see it!

 

Not a developer, but, wouldn't it be rather easy because the Apple II has no special circuitry. Just the 6502 and main memory/framebuffer.

 

Has anyone ever done a loop'de'loop in FS1? I never could no matter what. Though flying off-grid was a fun thing. We called it the Bermuda Box since strange lines would show up from time to time. We had so much fun with this. And it was one of the programs that got me hooked on the Apple II in 1979.

[ClausB]

3 hours ago, eebuckeye said:

Impressive.. where do you have information on the Exidy port?

 

The original port is on this site as a.wav file:

https://www.classic-computers.org.nz/blog/2017-01-23-software-for-real-sorcerers.htm

 

I'll send you my version if you'd like to test it out. It's a .com CP/M file.

[ClausB]

3 hours ago, Keatah said:

Has anyone ever done a loop'de'loop in FS1?

 

I've done a couple rolls. I'll try a loop and let you know.

[ClausB]

3 hours ago, Keatah said:

wouldn't it be rather easy because the Apple II has no special circuitry. Just the 6502 and main memory/framebuffer.

 

I think it would be easy to make a display list that mimics the Apple's HIRES memory map, replace the keyboard routine, and let the code run. Atari's GR.8 mode even has color artifacts like Apple, though they vary by machine. But early Apple software uses only 7 bits per byte of HIRES and Atari uses 8, so some code mods will be required.

Edited February 13, 2022 by ClausB

[ClausB]

3 hours ago, Keatah said:

it was one of the programs that got me hooked on the Apple II in 1979.

 

Just as Star Raiders got me hooked on Atari!

[Rybags]

Is the cockpit view always monochrome?

If it is then it might make conversion a whole lot easier.

[ClausB]

52 minutes ago, Rybags said:

Is the cockpit view always monochrome?

Typical Apple artifact colors. Screen shots above.

 

After figuring out the 7-bit to 8-bit thing, I would probably convert to mode E so the colors are consistent. The outside view is always monochrome and really just 140 pixels wide (2 bits per pixel).

[ClausB]

10 hours ago, Keatah said:

Has anyone ever done a loop'de'loop in FS1?

 

I tried several times, diving to 140 speed and pulling up varying amounts. It always just stalled and came back down.

[ClausB]

@Keatah, can you look in your A2 repositories for a FS1 binary? And even source code or a disassembly?

[Keatah]

No source as far as I can see. Maybe someone would care to write them at http://www.sublogiccorp.com/

 

There are 3 versions of the binaries:

sublogic_flight_simulator_1_with_docs.dsk

a2-fs1-docs.zip

 

Here is the original manual scan for the cassette 16K tape version #1

v1 subLogic FS1 - Tape Version.pdf

v1 sublogic FS1 Tape Version [OCR].pdf

 

Here is the pack-in additional addendum sheet for the 32K disk version #2

v2 addendum subLogic FS1 - Disk Version.pdf

reference cards.zip

 

I don't believe there are any manuals or scans specific to version #3, the one with the (slightly) expanded world. But from what I know the program operation and physics and controls are the same as version #2.

 

Then there are these which may provide some insight into subLogic's philosophy on graphics.

https://archive.org/details/artwick-1984-applied-concepts-in-microcomputer-graphics

https://archive.org/details/sublogic-a2-3d1-animation-package-photocopy

 

 

[youxia]

16 hours ago, Keatah said:

And it was one of the programs that got me hooked on the Apple II in 1979.

Are you sure it was 1979? I've spent quite some trying to find out its release date recently for my AII collection, and I think it was actually January 1980.

Edited February 13, 2022 by youxia

[Keatah]

I recall playing it in a Compu-Shop just weeks prior to Christmas 1979. Seeing that Champaign, IL. was only a short drive away, it would make sense they had a demo going.

 

The earliest official publication of the manual is the blue-copy, printed in January 1980. 1st edition, 1st printing. And it's reasonable to use that as the official release date.

 

I myself wouldn't actually purchase a copy till early spring when I could afford it. I clearly remember the salesman (had a 'fro a meter wide) showing me tons of Apple stuff over the 1979 summer. A2-FS1 wasn't out that early though.

[youxia]

This site has a quote from one of the founders: "I always believed that the program was made in 1979 but I was not sure about the year when it got in public. I can quote Stu Moment (I got his statement). "The program was really done later in 1979 and it was ready for distribution during a week after Christmas 1979". SubLOGIC “product status sheet” presents exactly December 31, 1979. Stu remembers that he had to write few apologetic letters to users who wanted to have Flight Simulator 1 as a Christmas gift. So, for real their product did not hit markets until 1980."

 

So I guess it's possible some local shops might've had a playable demo or an early version around that time. Or maybe it was the flight sim demo from that 3D routine package Bruce had released first (though this one was not playable).

 

In any case, you were lucky to be there then. Real videogame history in the making.

[ClausB]

Had my first look at A2-FS1 today. Thanks to @Keatah for the image. I had seen that the T80-FS1 display routine was largely table-driven, and A2's is no different. There's even a table for the 7-bit thing! That will make porting simpler.

[ClausB]

This first version had to run in 16K, even with HGR dsiplay mode active, which takes over 6K. So code space was tight. Instead of loading code to draw the instrument panel, it loads the bitmap directly. Here's what it looks like, converted to BMP. Every gap in the Apple's disjointed memory map is filled with subroutines, appearing here as random pixels. The dashed lines are due to that 7-bit thing.

 

a2.bmp

 

Edited February 21, 2022 by ClausB

[+Stephen]

9 minutes ago, ClausB said:

 

This first version had to run in 16K, even with HGR dsiplay mode active, which takes over 6K. So code space was tight. Instead of loading code to draw the instrument panel, it loads the bitmap directly. Here's what it looks like, converted to BMP. Every gap in the Apple's disjointed memory map is filled with subroutines, appearing here as random pixels. The dashed lines are due to that 7-bit thing.

 

a2.bmp 7.56 kB · 4 downloads

 

Edit: YTF can't I get the thumbnail to show here?

Post a jpeg, not a bmp, and the thumbnail should show up.

[ClausB]

I think it was 1984, June, when my friend Lance and his friend with a pilot license picked me up at Muskegon airport and flew a Piper Archer across Lake Michigan to Meigs Field in Chicago. From there we walked to McCormick Place and saw the wonders of Summer CES. subLOGIC had a large, open booth showing off FS2. There I met Bruce Artwick and told him how impressive his program was, which he already knew. I asked him whether it was realistic enough to teach flying. He said he thought so but you still have to take lessons in an actual aircraft.

 

Soon after I bought FS2 for the Atari and flew my 800 around a lot. In 1986 I earned my license and learned how risky it was to fly that single-engine Piper that far and that low over that cold water!

[Knimrod]

3 hours ago, ClausB said:

I think it was 1984, June, when my friend Lance and his friend with a pilot license picked me up at Muskegon airport and flew a Piper Archer across Lake Michigan to Meigs Field in Chicago. From there we walked to McCormick Place and saw the wonders of Summer CES. subLOGIC had a large, open booth showing off FS2. There I met Bruce Artwick and told him how impressive his program was, which he already knew. I asked him whether it was realistic enough to teach flying. He said he thought so but you still have to take lessons in an actual aircraft.

 

Soon after I bought FS2 for the Atari and flew my 800 around a lot. In 1986 I earned my license and learned how risky it was to fly that single-engine Piper that far and that low over that cold water!

I remember that!  I think the pilot was Doug (?) from the Atari club CHAOS and I think he was from Mason.  In that trip, we flew from Mason to Muskegon to pick you up and fly to Meigs CGX and back.  I don't remember for sure but either at start of trip or end of trip, our pilot departed Muskegon without clearance and was subsequently chewed out by the controller over the radio.  Oops.

[Gunstar]

A bit late to the conversation, but I think FS1 on the A8 would be very cool, if a better frame-rate can be had than FS2 on the Atari.

 

I know it's not your intention @ClausB, just putting it out there...Is source code available and has anyone looked into improving FS2 on the Atari? I'm just talking about performance of the frame-rate. For that matter, any other 3D vector graphic flight sims from back in the day. And if the programming code is already good and tight, what else could improve performance short of installing a Rapidus or similar? Newer, faster, floating point math in the OS maybe?

[Wrathchild]

I've disassembled Aviator from the BBC Micro and every now and then go back and try and decipher some more meaning from it. So if anyone fancies collaborating on that then we might see it quicker ?

[ClausB]

11 hours ago, Gunstar said:

Is source code available and has anyone looked into improving FS2 on the Atari? I'm just talking about performance of the frame-rate. For that matter, any other 3D vector graphic flight sims from back in the day. And if the programming code is already good and tight, what else could improve performance short of installing a Rapidus or similar? Newer, faster, floating point math in the OS maybe?

 

I'm not aware of any source code. FS2 is larger and more complex than FS1. I disassembled FS1 and have added some comments as I figure out the subroutines. I doubt AT-FS2 uses the OS math pack. It probably has optimized fixed-point math routines taken from the Apple version. I came across T80-FS1's multiplication routine, a fairly standard 16-bit shift-and-add. That could be sped up with a quarter-square LUT, but I'm not sure how often it's called. The line projector/clipper gets called a lot but it uses expanded shift-and-add routines that I don't understand. Anyway, once it's ported, we can mess with it.