ClausB

According to various web sources, the real artifact colors depend on the type of Atari computer and whether it has a GTIA or CTIA, making it complicated to emulate. IMO, Atari++ artifact emulation is disappointing. Haven't seen the others. Perhaps the Atari emulator authors could take a lesson here from Apple ][ emulators. The Apple's hi-res colors are generated by artifacting, and their emulator screen shots on the web look good.

Most 48K upgrades for the 400 used 64K chips, since there is only one RAM slot in the 400. Some of those upgrades wasted the extra 16K but others could access it through bank-switching, as posted above. Can you open it up and photograph it for us? Here's a DIY upgrade to 48K or 64K: http://www.atariage.com/forums/index.php?showtopic=123207&view=findpost&p=1488304

Cool! Thanks.

That link actually went right to the post for me. Can you give me some examples of links that give you 404 errors? Thanks, ..Al Please take pity on me; I'm using IE7. It's the links within that old post that give Error 404. Here's the quoted text, cut and pasted from that old post:

Very nice job! I noticed that some old posts' links to other posts give Error 404, such as the links in post #7 here: http://www.atariage.com/forums/index.php?showtopic=130011&view=findpost&p=1567342 Also, the link above goes to the topic, not the post.

I vote for a clear plastic top and LEDs inside. Take the ROM and RAM boards out of their cases too so you can see the guts. Wire blue LEDs to the RAM select lines (thru buffers), red LEDS to the ROM select lines, and green LEDs to the I/O select lines. Then watch the colors change as programs run and access the different areas of memory.

Thanks!

Pardon my ignorance, but how do you get the Atari emulator into the DS?

The Space Invaders kernel doesn't use multiple RESPx strobes per scan line either. Does Galaxian? Would that technique work? The Stella doc says strobing RESPx causes the player to redraw in the new position on the next scan line.

Very interesting book. A little thin, so I'm reading it again. The excerpt below seems to be in error. I looked at the Space Invaders kernel with the Stella debugger and there are not multiple HMOVEs per line. It looks pretty much like a typical six-sprite kernel. Does the technique described below even work? Do any games use it?

Seriously? THE source? Or a disassembly?

Any comments from the 25 downloaders?

Did you try reversing the polarity? That always worked for the Doctor!

My 1980 400 came with a 6502B. Not sure why they used a 3 MHz part in a 1.8 MHz machine, maybe marginal timing somewhere in the design? Maybe just better availabality at the time? Anyone know?

Very cool. Congrats!

I'll post it even if no one cares: It's a bootable disk 8K ATR (zipped). Like any good father would, I just gave my kids their first hacking lesson. Here is their effort, a hack of my first hack. I did mine with graph paper, a mental binary-to-hex converter, and Atari Assembler/Editor. Being twenty-first century kids, they drew the characters in MS Paint, transferred the hex values using MS Debug, and tested on Atari++. BI.zip

I still lurk here once in a while. Too busy with life for much Atari fun, so had nothing to post (though that never stopped me from posting before). Did read "Racing the Beam" recently - very interesting. Makes me want to try to write a 2600 game. I stopped working on SR HD last year because I hit a wall in understanding the disassembly. Would be nice to peek at the source. Here's how it looks in the higher resolution of mode E. The attached .XEX has my patches so far (plus some others' mods). It still has some problems, such as the stars losing vertical motion at the top and bottom, and some blinking in the middle. I don't like the way the rectangular stars look in an emulator or on an up-converting monitor, but on my plain old color TV, I think they look more like pinpoints, as stars should. SRE.zip

STAR RAIDERS

Has anyone found a North American version of this monitor yet? I searched for an hour and the best I could find had component and composite but no s-video. Anyone? look here http://www.lge.com/us/computer-products/monitors/index.jsp First one I looked at had s-video. Look at the pdf spec sheets to see all the inputs. They don't list everything on the web page specs. THis one looks good http://www.lge.com/us/products/documents/m237wdpmSpec.PDF As i have multiple retro consoles I think its time to replace my 19inch dell monitor... Thanks!

Has anyone found a North American version of this monitor yet? I searched for an hour and the best I could find had component and composite but no s-video. Anyone?

"Affirmative, Master!" "Analysis indicates Atari superior, Master."

Tent - check! Sleeping bags - check! Lantern - check! Wood - check! Beans - check! Atari - check! Wizards - check! Plasma - check! No, wait, take the LCD. We are roughing it, remember?

Here's one: http://www.atariage.com/forums/index.php?s...t&p=1486948

Some timing diagrams to chew on: Normal ANTIC DMA Read Cycle - 559 ns ___________________________ Phi2 \___________________________/ \ _ __________________________________________________ A0-15 _XXXXXX__________________________________________________ _ ___ D0-7 _>-----------------------------------<XXXXXXXXXXXXXXXX___ Double (LEM Stage 1) Read Cycle ___________________________ Phi2 \___________________________/ \ _ ______________________ ___________________________ A0-14 _XXXXXX______________________X___________________________ Bank 1 Bank 0 _ ______________________ __________________________ D0-7 _XXXXXXX______________________X__________________________ Triple (LEM Stage 2) Read Cycle ___________________________ Phi2 \___________________________/ \ _ ______________________ _____________ _____________ A0-14 _XXXXXX______________________X_____________X_____________ Bank 2 Bank 1 Bank 0 _ ______________________ _____________ ____________ D0-7 _XXXXXXX______________________X_____________X____________ The normal cycle has lots of dead time from when the address lines are stable to when the data lines need to be stable, because memory circuits were slow back then. ANTIC does not sample the data lines until the end of the cycle, when the Phi2 clock signal goes low. The LEM SRAM is much faster so we can squeeze more read cycles into each ANTIC cycle. The data from Banks 1 and 2 become the enhanced luma, while the Bank 0 data go to ANTIC as before.

Got a 400 2 years before my 800. The keyboard was not bad for a membrane, with the raised edges and speaker click feedback. And the RF output was sharp - sharper than an unmodded 800XL composite output. I love my Candy!