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Member Since 29 Sep 2005
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#3787391 fixing Doom for the 32x

Posted by Rybags on Sun Jun 18, 2017 10:40 PM

For sure?


You seemed to be struggling to do a Basic menu program for the Atari computer and now expect to graduate to modifying what's probably a 2 Meg or bigger game on a system that's about 10 times as complex.

#3786101 Cool 2600 games never released for 800/xl/xe

Posted by Rybags on Fri Jun 16, 2017 8:59 PM

Phoenix was a glaring omission.  Weird that they'd get the licence but not release it more widely, like at least on the 7800.

#3783939 Funny Atari Bruce Lee game reviewed.

Posted by Rybags on Wed Jun 14, 2017 8:05 AM

A 40-something male who has the demeanor and voice of a boy who's just started getting hair on his scrote.


Somewhat annoying, and the production is the same.  Just drags on, and the humour is forced and not effective.

#3783763 Learning Things About The 1200XL...

Posted by Rybags on Tue Jun 13, 2017 11:30 PM

The solution is to replace or bridge R63 with a piece of wire which will let the SIO device draw more power.



#3782950 Is there a game like C64 Traffic?

Posted by Rybags on Tue Jun 13, 2017 2:45 AM

Probably uses character or bitmap for the moving objects but likely there's a fair bit of attribute use as well.


Constant pitched white noise... gets annoying as hell after about 10 seconds.  The least they could have done was have some different noises for buses etc.  And maybe throw in some emergency vehicles that you have to clear a path for... or maybe it already has that, I didn't hang around for very long.

#3781520 65XE with Omniview ROMs - colors wrong

Posted by Rybags on Sun Jun 11, 2017 9:24 AM

The Omniview and Omnimon OSes have different default text background colour.  The emulator Roms I've got here use dark blue but I think I've seen a machine where it's been green.


A quick/easy way to check your colour adjustment is right is to start up with Basic.



SE. 2,9,4

should give the default light blue background most people are used to.


If you're not getting the proper colour then it's likely your colour pot needs adjusting, it's accessable from under the machine with a small slotted screwdriver.

Colour adjustment is best done with a screen displaying colour bars, there's various programs including quick type-ins that can do it.

#3780791 6502 machine language delay loop

Posted by Rybags on Sat Jun 10, 2017 11:41 AM

One of the keys to learning 6502 and most assembly languages is to know how the flags are affected by various instructions.

It saves doing unnecessary compare and other test instructions sometimes.

And in some cases you can just use the flags as input to future operations, e.g. carry flag after bitshift to an ADC instruction.

#3779453 NTSC core for VBXE?

Posted by Rybags on Thu Jun 8, 2017 9:01 PM

Lotharek makes and sells the VBXE now but I believe candle is probably more involved in development since it went to V2 back around 2009.


VBXE uses a modified LAOO.ACT palette which is biased more towards PAL than NTSC.

I've looked at the flashable core file and can't see any embedded data which looks like a palette.  It's a fairly easy scan since the core files seem to have lots of grouped zeros and palette files don't.

My guess would be one of these:

- palette not contained within normally flashed core area?

- the palette is compressed or stored out of normal RGBRGB sequence?

- the palette is derived procedurally?


The palette is 768 bytes so you may as well assume a 7-8 sector boot program to do your own every time if you go that route.

An alternative if you have a flashable multi-OS upgrade could be to do a modified OS.  Would probably be easiest to use the second character set to store the palette and initilization code which would only need to run on coldstart.

#3775996 Atari 2600 Emulator for A8?

Posted by Rybags on Sun Jun 4, 2017 6:09 AM

There was too little effort put into Jaguar software as it was - doing emulators would have just given them an excuse to do even less.


Still, it would be interesting to see an emulator done on the computer even if it resulted in a 2 fps slideshow.

#3775921 Paperclip Dongle

Posted by Rybags on Sun Jun 4, 2017 12:04 AM

The Leaderboard dongle protection was stupidly simple.  I cracked that game myself, from memory it did left/right stick at the same time, which I thought wasn't very smart as you could use a pair of taped down paddle buttons to simulate it if you couldn't be bothered with the buck-fifty worth of parts and 5 minutes worth of soldering to DIY dongle.

#3775755 Vertical Scrollers - thoughts on DLI effects

Posted by Rybags on Sat Jun 3, 2017 8:01 PM

A DLI every 2 character lines shouldn't slow things down much.


DLIs with scrolling have potential for problems but most can be solved with some thinking and flexible programming.

With HScrolling, more DMA which itself is variable means less cycles available.  If possible, only using larger HScrol values means the DMA window gets slightly smaller as it's cut off on the right hand of the screen.

With VScrolling especially where it's adjacent to static character display like a score panel there's potential for 2 or more badlines in succession.

e.g. If VScrol = 07 that means you get 2 badlines in a row.

That in itself isn't usually a problem but if DLIs are in use it can be.  If a DLI is needed on the last part of a static area before scrolling e.g. for colour changing then it might be a good idea to test for that successive DLIs condition and just jump into the second DLI's code after disabling the DLI NMIs - probably needing to add some delay to produce a similar condition to normal NMI entry.  Then just re-enable DLIs by default near the end of the following DLI when it's guaranteed a double-trigger won't occur.


"Kernal" type code blocks generally not the best idea if you want lots of processing time left over.

Another alternate can be Pokey Timers (e.g. Project M) but they have problems in that you need 16 KHz mode for the scanline synced mode and use of things like INIT or STIMER have unwanted effects on playing audio.

#3775366 Atari 2600 Emulator for A8?

Posted by Rybags on Sat Jun 3, 2017 8:05 AM

In some respects the 2600 PMs are more powerful than the computers - we lose the repeat ability which allows the 2600 to have 6 for the price of 2.


What kills the idea more than anything though is the cycle dependant positioning.  There's just no easy way to run native 6502 code then detect what cycle offset a register hit takes place on when the hosting machine is less than about 50 times as fast.

#3774588 screwing with pirates

Posted by Rybags on Fri Jun 2, 2017 5:54 AM

Then you have the modern day.


DVD/Bluray - put half a minute of copyright and legla crap that plays every time and can't be skipped, annoying those who've payed for the thing.  First thing anyone who pirates a movie does is remove that crap, so encouraging people to just source the free version in the first place.


Games - squeeze every last cent out of the punters.  Sell "extra content" instead of having an open modding community.  Have games perform online licence checks every time you start them.  Remove online servers for multiplayer and licence checking after 3 years, rendering legal copies of the game useless.

#3774363 screwing with pirates

Posted by Rybags on Thu Jun 1, 2017 8:08 PM

Pity.   I was eagerly awaiting the next release.

#3771905 Images generated by RastaConverter

Posted by Rybags on Mon May 29, 2017 10:19 AM

I don't get it - there's no way it looks like 102 colours, if I was asked I'd say half or less.  But I saved and used IrfranView and it confirms 102.