I'm not very familiar with Bosconian, so I've decided I best put in some time to get a better understanding of how it plays. I cut the cord a few years back and use a Mac mini to drive my TV. Besides DVR software for broadcast TV, I've installed MAME, Stella, and OpenEMU on it. I also have a couple PS3 controllers that are paired via bluetooth. Works quite well.
The current game logic for Draconian was mostly written back in 2014 and, for the most part, I was able to drop it into the new C
This blog entry is short and sweet!
All the features of the last DPC+ version of Draconian are back in place, so the game is once again playable.
As a reminder the difficulty switches are currently used for:
Left: A = display VB and OS time remaining (only meaningful on real hardware), B = display score
Right: A = freeze screen (used to review the graphics and animation sequences), B = fly around
For Harmony or Stella (requires Stella 5.0.0-pre8 or newer)
Starfield's back. New station cores are in place, they look awesome! As a reminder, this is what they looked like in the DPC+ version: Due to TIA limitations, the station cores may not always be drawn in red when 2+ are shown in the same horizontal zone. In this screenshot taken with phosphor mode on: you can see how flicker logic causes the rightmost station's core to change colors because on some frames it must be drawn using a missile instead of the ball. Also note that there'
While there's still more to do with it, the Missile engine's been rewritten to support line by line HMOVEs. Additionally, it can now use the ball object to draw things. In all prior builds the ball was limited to drawing the starfield. Starting from the top:
horizontal player shot
diagonal player shot
diagonal player shot
vertical player shot
station shot (animated)
horizontal energy field (animated)
vertical energy field (animated)
From left to right the objects are dr
Both players are being used to draw all the sprites, the 3 dotted lines are drawn using the missiles and ball. You can move the blue sprite around with the joystick, as it crosses paths with the other sprites the players will flicker. Hold fire to move slower. The white dot in the radar will show the location of the blue sprite within the world. Right Difficulty = A to show the use of HMxx to shift the missiles and ball back & forth on every scanline. The missile/ball routine
This tutorial covers the writing of a 2K game for the Atari 2600. Since it's a tutorial, I put significantly more comments in the source code than I normally would. So be sure to download the source and read it along with each blog entry.
The tutorial does assume you have some understanding of 6502 assembly language. If you don't then check out the Easy 6502 tutorial before starting this tutorial - don't worry, it's not a difficult processor to learn*
Let's Make a Game!
goals for
Game screen's been rewritten to update the audio sample on every scanline. Squeezing it into the score display area was a bit tricky, ended up replacing the original loop logic with the new Fast Jump feature. The radar's currently showing a test pattern to confirm it's displaying 8x16. Left Difficulty A to show the text display, though I'm not sure if we'll need the alpha characters anymore since we have speech samples. For Harmony on a 2600* draconian_20170514.bin * we discover
Per Wiki there's 5 phrases that can be said:
"Blast off!" (start of a round)
"Alert! Alert!" (enemies approaching)
"Battle stations!" (formation attack)
"Spy ship sighted!" (Spy ship advancing)
"Condition red!" (enemy attacks become more aggressive; occurs when the player takes too long to clear a round, or misses the spy ship)
Preliminary samples are in place, and currently take up 7107 bytes of ROM. Ironically "Alert! Alert!" takes up the most space:
1979 alertalert.pds1335
We've finalized the CDF spec, which has seen a major overhaul, and I've finished updating Stella to support it. As such I've resumed work on Draconian. Currently the title screen & menu are back in place. All the routines have been rewritten due to the spec change. I also revised them for digital sample support, which requires 5 cycles of time on every scanline (though at the moment that's just a SLEEP 5, it'll be replaced with LDA #AMPLITUDE/STA AUDV0 when I'm ready for the samples).
Like Doctor Who, for which I'd just received DVDs for season 9(1972) from the UK as PAL DVDs have 20-30% more detail than NTSC DVDS (which is quite noticeable on an HDTV), I decided to go back to the very beginning of Star Trek and rewatch everything in order. I recently wrapped up the last season of TOS (The Original Series) and had started in on TAS (The Animated Series). I decided to start ripping the movies when I realized I only had 1-8 on Laser Disc: However, my Laser Disc player ha
Last time around cd-w made a comment that led me to doing a test rewrite of one of the ball reposition kernels:
DS_GRP0 = DS1DATA
DS_GRP1 = DS2DATA
DS_HMP0_ENAM0 = DS3DATA
DS_HMP1_ENAM1 = DS4DATA
DS_HMMB_ENABL = DS5DATA ; HMxx for missile/ball, ENABL
DS_COLOR = DS6DATA ; COLUP0, COLUP1, COLUPF - only used during reposition
DS_SIZE = DS7DATA ; NUSIZ0, NUSIZ1, CTRLPF - only used during reposition
DS_JUMP = DS8DATA
RealResblStrobe73:
Kernel revisions panned out - the ball object can now be resized and recolored. The draw missile routines haven't been updated yet to use the ball as a last resort, so to test the resizing I've temporarily modified the stars to have different widths. I also added some missiles that fly around in a formation just below the enemy formation (they're easy to spot in motion). I see some stray graphics every once in a while that I'll need to track down, such as the 2 purplish dots at the bottom-
The ball reposition kernels have been rewritten, the starfield has been reimplemented, and you can fly around the sectors. ROM requires Harmony or Stella 5.0.0-pre6 or newer. draconian_20170328.bin
Both missiles are being used to draw all the objects. You can move one of them around with the joystick. Position within the world will be shown using the score as well as in the radar. Like the sprites, I had to add an extra scanline of delay after the reposition occurred else the top scanline of the missile would disappear when it was positioned on the left edge of the screen. For the sprites the routines would try to draw using player0 first, then player1. For the missiles the routine
Both players are being used to draw all the sprites. At the initial position there will not be any flicker. The blue test sprite can be moved around with your joystick, the score is used to show your X and Y position. Hold fire to slow down the movement. During tests I did discover a minor issue, which was most likely present in the DPC+ version as well. X position 4 the sprite looks OK (cropped due to HMOVE bar). However, at X position 3 the first line of the sprite is missing! I
Player0 and Player1 reposition kernels have been rewritten, but are not yet being tested so the test pattern goes straight down. Still need to redo the reposition kernels for the missiles and ball. The score/radar/lives/formation routines are functional. If you change the QUADRANT and/or SECTOR in the menu the correct station layout will appear in the radar. For testing the score will increment, lives decrement, the enemy formation is flying in a circle, and the player's ship moves southeas
Joystick up/down selects menu option, joystick left/right/fire changes value. We've figured out a way to do NTSC vs PAL detection, so I've set it up so TV-TYPE will be automatically set. The START option is currently overwritten to display detected console on the left, and timer value on the right. The timer value is used for the NTSC/PAL detection, so if yours is detected incorrectly please post a reply with the timer value, expected TV Type, and console (2600, 7800, Coleco Gemini, etc).
The development of Bus Stuffing took far longer than I expected. While the results are awesome:
(yes, these are actual images generated by my 2600!) regrettably some 2600 Junior and some 7800 consoles just don't work correctly with it, resulting in vertical lines, incorrect colors, and even system crashes: It appears to be a hardware issue with those systems, and I don't wish to offer up games for sale that won't work on some 2600s (I'd be OK if the problem was restricted to some 7800
My sister likes to bring my nephew and a few other kids for an extended weekend to do some holiday sightseeing in Houston. I try to find something different to do every year, and this year was no exception! They got here on Saturday, the 17th, and we started them off making Melted Snowman Cookies:
bake sugar cookies
frost them with white cookie icing (the kind that eventually sets up hard)
microwave marshmallows until they just start to puff up
position the marshmallows - as they cool
Received a question via Messager that I'm going to reply to here as others may find it interesting as well:
Long story short, extra hardware in the cartridge.
Short story long, one or more of the following are added into the cartridge:
Extra ROM
When the Atari was designed ROM was expensive so they only used 2K for the games (think Combat, Air-Sea Battle, etc). They did plan ahead though and designed the Atari so it could use 4K ROMs. As the cost
First off I see that Tablo's having a Black Friday sale. Free antennas (just pay $12 for shipping) and discounts on Tablos. As of Saturday morning one antenna model is sold out, but another remains available as do the Tablo discounts. When we set up the antenna we took a small TV outside and plugged it in via a coax cable. We did that to help with the alignment, plus we didn't yet know where the other end of the existing cable went. After I'd left they noticed a couple channels they wa
Was down at my folks' place yesterday. We installed the antenna using the existing coax cable from their old satellite dish. I wasn't able to remove the old mounting plate as their roof had been redone and the upper bolts were blocked by a new piece of metal trim. I then climbed through their attic to find the other end of the coax and connect it to the cable outlet in their bedroom as they wanted to set up the Tablo on the small shelf behind the wall mounted TV. We then set up their 4 tu
My fire TV arrived today, it's quite small: I don't have a new TV yet, and my old TV won't support it, so I have it plugged into one of my 4K monitors. 4K content looks awesome on it, as though I were looking out a window: I've resubscribed to HBO NOW and had an unexpected surprise - another 30 day free trial : I did have a minor issue though, after subscribing I could watch on the fire TV, but not via my iPad or browser on the computers. I contacted HBO and they told me I should hav
In regards to the iTunes Store support failure, I've decided to continue purchasing à la cart TV content via iTunes due to how much better it works with my setup - namely because I can't download episodes from Amazon to my Mac mini and must stream them with occasional picture quality issues. For HBO and Showtime I'll most likely resubscribe via Amazon. Showtime will cost less than via iTunes, and can be added to Prime directly. HBO NOW will cost the same, but must be subscribed to via a devi
I enjoyed season 1 of Killjoys, so when season 2 showed up for pre-order in iTunes back in June for $19.99 I bought it. I didn't start watching the series right away, but when I finally got around to watching episode 1 I thought it was rather odd that it ended without any ending credits. So I dropped iTunes Support a note on July 23rd:
On the 26th they wrote back:
I thought refunding the entire purchase was an odd response, but then thought perchance that was a way of saying "thanks