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Defender's radar: can anyone fix it?


highinfidelity

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Good afternoon gents.

 

Yesterday I tried Defender on my Colecovision console for the first time (well okay, that's being late!) and saw that the radar is blank. I've read this old thread here and it seems this is a common and somehow expected problem:

 

http://www.atariage....ap-doesnt-work/

 

Now the question is: has anyone found or selected a ROM image that doesn't show this problem? Is anyone able to and willing to fix any of the ROM images available so that ther radar will show up correctly?

 

By the way, I was very impressed by such a HUGE issue and I wonder how it could go under silence back then in the eighties. OK for the first production batch, these things may happen, but how could it be they didn't fix it in the next batches?

Edited by highinfidelity
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I gave a look to Defender. This happens because the PAL VDP has a larger retrace time and it updates its sprite table too early so the radar doesn't appear on screen.

 

Patch following ROM locations:

 

$0172 = $0c

$0173 = $80

$000c = $01 $80 $00 $0b $78 $b1 $20 $fb $c3 $75 $dd

 

It works in my private emulator in PAL mode, of course the real test would be over a PAL Colecovision.

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Now that's what I call hitting the bull's eye! ;-) :thumbsup:

 

Unfortunately I'm quite clueless when it comes to ROM, dumps and all that stuff. :dunce:

I didn't understand if you built up the fix inside the emulator settings, or if you actually modified the ROM file and fixed it permanently. if the latter is the correct case, could you please pass it to me as attachment via PM or email or attached to the next post? I'd be very glad to try out the fixed ROM on real hardware. 8)

Edited by highinfidelity
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I leave the work to publish a modified ROM to someone else :) (I'm pretty new to this forum and I don't know if the rules allow it)

 

Just download the Defender ROM file from somewhere in the net, download a hexadecimal editor an apply the patch on the addresses I've marked.

 

It looks like this hexadecimal editor can do the job http://www.chmaas.handshake.de/delphi/freeware/xvi32/xvi32.htm

Edited by nanochess
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I suspose a bigger issue is why AtariSoft did this 'error' in the first place and why it was never fixed. :)

 

Is there a Defender CBS version. I don't remember seeing it? If there is one then yes I guess they must have produced them without testing them for some reason. If there is not a CBS version then I would say the answer is that they never developed a version for PAL. If there is no CBS cart then they did not intend this game to be placed on PAL hence they didn't test it and didn't know about the bug.

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Defender doesn't work right on a standalone Coleco Adam either. Pressing "up" on the joystick doesn't work and the right side fire button (for smartbombs) doesn't work. Everything else seem to run fine.

 

Didn't someone fix that and release an updated ROM to fix that ADAM problem? I could swear someone did it within the last few years...

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Didn't someone fix that and release an updated ROM to fix that ADAM problem? I could swear someone did it within the last few years...

 

A quick search I turn up multiple topics of people talking about this problem but nobody fixing it and giving a rom.

 

Maybe one of your super secret contacts gave you one :)

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Defender doesn't work right on a standalone Coleco Adam either. Pressing "up" on the joystick doesn't work and the right side fire button (for smartbombs) doesn't work. Everything else seem to run fine.

This trigered my curiosity and I gave another look. The original ROM doesn't have waiting time between selecting joystick/keyboard ports, so that could be the problem.

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This trigered my curiosity and I gave another look. The original ROM doesn't have waiting time between selecting joystick/keyboard ports, so that could be the problem.

 

That sounds a lot like the problem I had with Pitfall II Arcade not working on the ADAM. The control issues were fixed prior to release, thanks to Bruce Tomlin's help. :)

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Didn't someone fix that and release an updated ROM to fix that ADAM problem? I could swear someone did it within the last few years...

 

A quick search I turn up multiple topics of people talking about this problem but nobody fixing it and giving a rom.

 

Maybe one of your super secret contacts gave you one :)

 

Adam's House (eColeco) had a fixed version back in the day but they were already sold out by the time I got back into Adam collecting in 2007.

Edited by ed1475
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This trigered my curiosity and I gave another look. The original ROM doesn't have waiting time between selecting joystick/keyboard ports, so that could be the problem.

 

Perhaps this "waiting time" issue is related to a problem I see with my Wico Command Control Stick. All 5 fire buttons do the same thing on Defender: They fire AND deploy smart bombs simultaneously. When I use the Colecovision Test Cart, the joystick buttons test correctly. Defender seems to have some crazy issues!

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By the way, this raises a question: Is the ADAM computer in Europe PAL as well?

I have personally NEVER seen or heard of a CBS European PAL version of the STAND-ALONE ADAM COMPUTER WITH THE COLECOVISION built-in. The only ADAM Computer system that was sold in Europe that I know of was the Expansion Module #3 ADAM Computer which of course requires a ColecoVision to attach to and then uses the ColecoVision's RF output... so therefore the output is in PAL format.

 

Coleco or Coleco of Canada did release the Stand-Alone ADAM Computer (big blue lettered box) in Canada for the French market there (french language box, manuals, etc.) and PERHAPS some of these made their way across the ocean and were sold, but I highly doubt it due to a couple issues...

 

- The Power Supply in the printer would have had to be swapped out or converted, obviously.

- The video output would have had to be changed to PAL format, again, obviously.

 

I mean, if someone makes a fix for Defender, there should actually be two fixes, namely "NTSC + ADAM compatible" and "PAL + ADAM compatible".

Defender was fixed sometime around 1986 or 1987 by Jim Walters, a homebrew programmer back in the day for the ADAM, and the fixed rom image was made available to the ADAM Community on a self-booting Data Pack or Disk. My mail-order company would include this fixed Data Pack version with each Defender CIB that we sold... and we had a lot of them (probably 100) when I first started there.

 

This fixed rom version was later placed onto a cartridge by CBS Eletronics and sold by ADAM's House/eColeco and you can see a picture of the cartridge with the edited label below.

 

Parker Brothers did not release specific versions of their cartridges for the North American and European markets... only the box changed to support multiple languages.

 

To borrow a phrase from a famous movie, "This house is clean". :P

post-25956-0-71348000-1357341169_thumb.jpg

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This fixed rom version was later placed onto a cartridge by CBS Eletronics and sold by ADAM's House/eColeco and you can see a picture of the cartridge with the edited label below.

 

Okay so the obvious question here: Is that your cart in your picture? Whether it is or not, do you have the ROM of the ADAM fix? :)

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Okay so the obvious question here: Is that your cart in your picture? Whether it is or not, do you have the ROM of the ADAM fix? :)

:woozy: Sadly, I must state that the cart in the picture is not mine and I don't own one anymore... sold with my original collection years ago! :woozy:

 

However, I think I have this patched ADAM version on one of the CopyCart compilation disk images and will make a note to myself to look for it. If I have this version, I can pull it off the disk image and convert it back to a PC rom image file and then post on here.

 

If, in the meantime, someone has this fixed ADAM version, please post it here for everyone's benefit and to save me some time.

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This patch detects automatically if there is a PAL Colecovision and adds delay, but not for NTSC :)

 

Also added delay to solve bug with controllers in Coleco ADAM (not tested, but it should work)

 

If anyone publishes a patched ROM, please DON'T give me any credit. It is only my little contribution to the community.

 

Address

Original byte

New byte

$000C = $00 -> $3A

$000D = $00 -> $69

$000F = $00 -> $FE

$0010 = $00 -> $32

$0011 = $00 -> $20

$0012 = $00 -> $08

$0013 = $00 -> $01

$0014 = $00 -> $BA

$0015 = $00 -> $01

$0016 = $00 -> $0B

$0017 = $00 -> $78

$0018 = $00 -> $B1

$0019 = $00 -> $20

$001A = $00 -> $FB

$001B = $00 -> $C3

$001C = $00 -> $75

$001D = $00 -> $DD

$0172 = $75 -> $0C

$0173 = $DD -> $80

$020F = $3E -> $D3

$0211 = $D3 -> $E3

$0212 = $80 -> $E3

$0551 = $3E -> $D3

$0553 = $D3 -> $E3

$0554 = $80 -> $E3

$074D = $00 -> $E3

$074E = $00 -> $E3

$2FEB = $3E -> $D3

$2FEC = $80 -> $C0

$2FED = $D3 -> $E3

$2FEE = $C0 -> $E3

$3019 = $3E -> $D3

$301A = $80 -> $C0

$301B = $D3 -> $E3

$301C = $C0 -> $E3

$304B = $3E -> $D3

$304C = $80 -> $C0

$304D = $D3 -> $E3

$304E = $C0 -> $E3

$306D = $3E -> $D3

$306E = $80 -> $C0

$306F = $D3 -> $E3

$3070 = $C0 -> $E3

$324F = $3E -> $D3

$3250 = $80 -> $C0

$3251 = $D3 -> $E3

$3252 = $C0 -> $E3

$327F = $3E -> $D3

$3281 = $D3 -> $E3

$3282 = $80 -> $E3

$32B0 = $3E -> $D3

$32B2 = $D3 -> $E3

$32B3 = $80 -> $E3

$32C7 = $3E -> $D3

$32C9 = $D3 -> $E3

$32CA = $80 -> $E3

$32D6 = $3E -> $D3

$32D8 = $D3 -> $E3

$32D9 = $80 -> $E3

Edited by nanochess
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