Atari XE Battlezone is a port of the VIC-20 Version?!?!

[Tempest]

I managed to recover some old emails that I had lost years ago the other day.  Among those emails were some from Curt Vendel who had sent me the some of the source code for the Atari XE version of Battlezone.  Peaking at the code there are some VERY interesting comments in it:

 

; Battlezone for the Atari 400/800/XL/XE 32K RAM minimum
; copyright 1987 Atari Corporation
; all rights reserved.
; converted from Vic-20 version
; ORIGINAL SOURCE CODE USED WHERE POSSIBLE
; Therefore I refuse to take any credit for the comments that
; are difficult to read - that's the way I got 'em!
;
; Atari 800 version by Ken Rose for SofTalent
; Assisted by Mark Hemsley

; Keyed in from VIC-20 paper listing by Kirt Grubbs.  (Thanks a lot!!!!)

 

Converted from the VIC-20 version?!?!  This may be a first!

 

BTW here's the file itself.  Too bad it's just the header file.

 

BZ.SRC

[zzip]

Makes sense to reuse code where-ever possible I guess

[+Stephen]

Interesting - would have never thought VIC-20 code would be used.

[+kheller2]

Who wrote the VIC version?   Perhaps it was sampled from something else as well.

[R.Cade]

Makes sense. It looks VERY similar.

 

Edited December 2, 2021 by R.Cade

[xrbrevin]

explains why i was disappointed with the A8 version but if i was a Vic20 owner i wouldve been impressed!

[glurk]

I wasn't aware that there WAS a VIC-20 Battlezone.  I looked it up, and it looks really good.  Maybe the best VIC-20 game I've seen.  Had kind of forgotten about all of those old Atarisoft ports that they did back then.

 

[gilsaluki]

5 hours ago, xrbrevin said:

explains why i was disappointed with the A8 version but if i was a Vic20 owner i wouldve been impressed!

At first I thought the A8 version was just a short cut to get money into the Atari coffers.  That was before I knew about Vector Graphics on the Arcade version of BZ (which I believe is what they were trying to replicate).  I have learned to love the A8 version for many years.  Still a go-to cart for me.  I lose it on the third flying (thingy) saucer that heads straight for your tank.

[abbotkinneydude]

At that rate, we'll soon learn that the A8 XEGS version of DESERT FALCON was ported by Ken Rose from the 7800 source. This wouldn't be surprising.

[Lostdragon]

18 hours ago, Tempest said:

I managed to recover some old emails that I had lost years ago the other day.  Among those emails were some from Curt Vendel who had sent me the some of the source code for the Atari XE version of Battlezone.  Peaking at the code there are some VERY interesting comments in it:

 

; Battlezone for the Atari 400/800/XL/XE 32K RAM minimum
; copyright 1987 Atari Corporation
; all rights reserved.
; converted from Vic-20 version
; ORIGINAL SOURCE CODE USED WHERE POSSIBLE
; Therefore I refuse to take any credit for the comments that
; are difficult to read - that's the way I got 'em!
;
; Atari 800 version by Ken Rose for SofTalent
; Assisted by Mark Hemsley

; Keyed in from VIC-20 paper listing by Kirt Grubbs.  (Thanks a lot!!!!)

 

Converted from the VIC-20 version?!?!  This may be a first!

 

BTW here's the file itself.  Too bad it's just the header file.

 

BZ.SRC 4.42 kB · 14 downloads

Great bit of info and really helps explain why the XE version was far from all it might of been. 

 

I'm not familiar with the Vic-20 hardware, so not sure how easy it would of been to reuse existing code, but the practice fits in well with what i have heard about Atarisoft at the time. 

 

Thanks for sharing. 

[Tempest]

4 hours ago, Lostdragon said:

I'm not familiar with the Vic-20 hardware, so not sure how easy it would of been to reuse existing code, but the practice fits in well with what i have heard about Atarisoft at the time.

I'm not really either beyond knowing it also uses a 6502.  What I'm really curious about is why they didn't just polish up the unreleased Atari 5200 proto?  I'm assuming it's because they didn't have access to the source code for that version (done internally at Atari) and used whatever source code they could get their hands on when Atari contracted them (they also did the Vic-20 version).  But why did Atari decide to entirely redo Battlezone in the first place when they had a perfectly playable prototype already?  Also why does the XE version need 32K if it's a port of the VIC-20 version?  Lots of questions...

[zzip]

4 hours ago, Lostdragon said:

I'm not familiar with the Vic-20 hardware, so not sure how easy it would of been to reuse existing code, but the practice fits in well with what i have heard about Atarisoft at the time.

It's a 6502-based system as well, so they could reuse a lot of the game logic,  I imagine most work would be around porting graphics/sound.

 

6 minutes ago, Tempest said:

I'm assuming it's because they didn't have access to the source code for that version (done internally at Atari) and used whatever source code they could get their hands on when Atari contracted them (they also did the Vic-20 version).  But why did Atari decide to entirely redo Battlezone in the first place when they had a perfectly playable prototype already?  Also why does the XE version need 32K if it's a port of the VIC-20 version?  Lots of questions...

Yeah I would guess the third party didn't have access to the proto.   Also I'm guessing the 5200 proto was done under Warner and this was done several years later under Tramiel?   It's possible whoever commissioned it wasn't even aware there was a 5200 prototype.

[FifthPlayer]

10 hours ago, Tempest said:

What I'm really curious about is why they didn't just polish up the unreleased Atari 5200 proto?

I just looked at YouTube vids for all three versions (VIC-20, A8 and 5200) and the A8 version, despite being a port from the VIC-20 is a much superior port than the 5200.  The 5200, despite the colored mountain range in the background, has really chunky graphics and the scenery literally scrolls left and right without any hint of 3D perspective.

Edited December 4, 2021 by FifthPlayer

[+slx]

On 12/3/2021 at 10:57 AM, Lostdragon said:

I'm not familiar with the Vic-20 hardware, so not sure how easy it would of been to reuse existing code, but the practice fits in well with what i have heard about Atarisoft at the time. 

 

Interesting direction to port. Apparently the VIC20 had no real bitmap mode but something that would use a redefined character set as a pseudo bitmap. Must have been quite a challenge to fit everything into 5K of memory.  

 

[oracle_jedi]

On 12/3/2021 at 6:43 AM, Tempest said:

  Also why does the XE version need 32K if it's a port of the VIC-20 version?  Lots of questions...

The VIC20 version is a 16K cartridge sitting as two 8K banks at $A000 and $6000.

 

The program would be able to avail itself of most of the 5K of RAM to handle variables and manage the display.

 

Assuming that the source comments mean that 32K is needed to execute the code, and not in addition to code loaded as cartridge, the Atari version then would need at least 16K for code, plus whatever RAM is needed to support the graphics mode - which is typically at least 8K.   Plus some overhead for variables and we are at 32K. 

[Tempest]

Huh I guess so.  Just seems funny that a VIC-20 'port' needs so much memory.

[oo7]

Looking at this topic makes me scratch my head.

 

they ported code between two systems who run on the exact same processor architecture. Not shocking. Not even remarkable. Its as remarkable as using 600xl code on a 130xe release lol. I thought atarians today still using this platform would of learned something about computers between 1979 and 2021

[+Stephen]

46 minutes ago, oo7 said:

Looking at this topic makes me scratch my head.

 

they ported code between two systems who run on the exact same processor architecture. Not shocking. Not even remarkable. Its as remarkable as using 600xl code on a 130xe release lol. I thought atarians today still using this platform would of learned something about computers between 1979 and 2021

That's not the issue at all.  We obviously know what machines had a 6502 in them.  The video hardware is vastly different.  Game logic being shared, completely.  Screen rendering - we could be talking char mode vs bitmap mode, different resolutions, different bit patterns for colour handling, etc.

 

Also, hearing they took code for a limited 5kB machine, and ported it to our much more powerful machine is the surprise.

[oo7]

2 hours ago, Stephen said:

That's not the issue at all.  We obviously know what machines had a 6502 in them.  The video hardware is vastly different.  Game logic being shared, completely.  Screen rendering - we could be talking char mode vs bitmap mode, different resolutions, different bit patterns for colour handling, etc.

 

Also, hearing they took code for a limited 5kB machine, and ported it to our much more powerful machine is the surprise.

Another machines limitation is irrelevant if compatible code is ported. Sorry but that is fact. Its basics.

[Rybags]

There might be some emulation layer stuff going on which could explain memory bloat.

 

Vic-20 typically does 22 characters which we can sort of emulate with DList and wide mode tricks.

Redefined characters for graphics - we can run into trouble thanks to the 128 vs 256 definable characters.

I've not really played BZ on any home system so would need to check these various versions out.

[Mazzspeed]

I had no idea Battlezone even existed for the VIC-20. I actually had no idea an unexpanded VIC-20 could even run it, but based on the fact it runs of a cartridge does make sense in this regard.

 

I'd actually like a VIC-20 with all the expansions, including a hardware 40/80 column adapter; the problem is the VIC-20's stupid memory map when expanded necessitating the need to keep switching memory expansions off and off when required - A major PITA.

 

A very interesting thread, cheers to the OP.

[Mclaneinc]

On 12/3/2021 at 2:52 PM, zzip said:

It's a 6502-based system as well, so they could reuse a lot of the game logic,  I imagine most work would be around porting graphics/sound.

That's exactly what I was going to type, if the logic is sound then use it, the problem is whether the programmer makes better use of the actual hardware it's on now. Some do, some don't.

 

I suppose a lot depends on how quickly the port is wanted out in the shops, a guy named Peter Johnston used to port pretty much everything from ST to Amiga and he never used an ounce of the Amiga hardware to make it better. Seems that his main part of the contract was to get it done ASAP...

Edited December 5, 2021 by Mclaneinc

[Lostdragon]

1 hour ago, Mclaneinc said:

That's exactly what I was going to type, if the logic is sound then use it, the problem is whether the programmer makes better use of the actual hardware it's on now. Some do, some don't.

 

I suppose a lot depends on how quickly the port is wanted out in the shops, a guy named Peter Johnston used to port pretty much everything from ST to Amiga and he never used an ounce of the Amiga hardware to make it better. Seems that his main part of the contract was to get it done ASAP...

That's a little unfair on Peter Johnson. 

 

Having spoken with him briefly back in the day, regarding his work on both the ST and Amiga, I personally found him to be very open and honest when it came to admitting the Amiga versions were often little more than ST Ports, think Amiga Robocop at best had 2 extra speech samples, not present in the ST version. 

 

 

You only have to look at conversion houses like Tiertex, who paid Amiga coders the same to port ST code over and get started on the next project as they did coders who wrote from the ground up, for the Amiga hardware. 

 

 

With Peter, you need to appreciate it was Ocean Software, not Peter himself who promised the Amiga version of Robocop, would take full advantage of the Amiga hardware.. 

 

It was Ocean Software who then told Peter the game had to be ready for the home VHS tape release of the film, so Peter had to port the ST version over. 

 

Peter has made clear he wanted to use the Amiga hardware scrolling for example, the masked ST scrolling was ugly and done to get around the hardware restraints on that platform. 

 

 

Peter and many others working for prominent UK publishers/developers like:Probe, Tiertex, US Gold, Ocean etc, all had their hands tied, often had to come in to rescue code and work under strict commercial deadlines. 

[Mclaneinc]

 

I thought I was pretty fair on Peter, I'm not saying he deliberately neglected a better port, it's purely he was contracted to do it asap. A flip screen non scroll in a game at that time was just wrong, but I knew he wanted to do a better job. I remember asking the Ocean rep at the show if it was going to be a proper Amiga game, and he gushed "oh yes, we will use every part we can", my first thought was "BS".

 

But the whole point is if we should use pre-written code and the answer is Yes, as long as it's proven well written code. The fact that many coders had pre-written code modules that they plug in (as it were) says it's a normal practice. Why reinvent an input system when you have a perfectly good one which is pre-coded..

[youxia]

It really was a different, sink or swim kinda time. Most of software companies didn't have huge warchests allowing for long term strategies, and the landscape was changing year-to-year. They all needed profits as fast as they could get them. Hence there weren't that many exclusives: most of the good games would be ported across the whole 8/16 bit microcomputer spectrum, no matter the hardware specs. Sometimes they managed to improve things or at least not make them much worse, but often the only thing that mattered was the deadline. Publish and be damned!

 

The first 2 years of Amiga's line up are littered with ports from inferior hardware, often quite ancient ones - eg games such as Temple of Apshai or Oo-Topos.