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EricBall

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    320 mode colours question

    in Atari 7800 Programming

    BeOS software collection

    in Buy, Sell, and Trade

    Posted

    I'm giving away my BeOS software collection for the cost of shipping from Markham Ontario

    BeOS release 3 retail box (in fair shape), User's Guide to BeOS release 3

    BeOS release 3 Intel Pentium & PowerPC install CDs, diskette & install guide

    BeOS release 3.2 for Intel Pentium Demo CD rev 2

    BeOS release 4.5 Demo CD (and CDR copy w/ boot diskette)

    BeOS 5 Personal Edition CDR

     

    DM me you're address if you're interested

    • Like 1

    OS/2 software collection

    in Buy, Sell, and Trade

    Posted

    I'm giving away my OS/2 software collection for the cost of shipping from Markham Ontario

    OS/2 Warp retail box (in rough shape), User's Guide to OS/2 Warp and other retail manuals

    Original CDs: OS/2 Warp v3, BonusPak for OS/2 version 3, Home Connectivity v2 and v3, Developer Connection for OS/2 volume 5 1994 disc 1, Hobbes Ready-to-Run November 1994, Hobbes Archived March 1995

     

    DM me you're address if you're interested

    • Like 1

    Original Gravis UltraSound

    in Buy, Sell, and Trade

    Posted

    I bought this card new and upgraded the RAM to 1MB, but it has been sitting in my basement for decades and it's doubtful I will ever own a computer with ISA slots again.  So I'm hoping that someone else can give it a proper home.  It can be yours for $100 Canadian + shipping.  I will also include 24 3.5" disks with v1.21 (original), v2.06L, v3.53 and v4.11 software & patches.

     

    DM me if you are interested and let me know why you want this piece of history.

    DSC01307.JPG

    • Like 1

    SOLD! 64k CoCo2 w/ carts

    in Buy, Sell, and Trade

    Posted · Edited by EricBall

    Clearing out the basement and have the following in need of a good home.

     

    (Tandy) Radio Shack TRS-80 64 Color Computer 2

    4 original one button analog joysticks

    classic RF switch box & cable

     

    Working Carts:

    Chess (w/ manual), Color File (w/manual), Dungeons of Dagorath*, Galactic Attack, Math Bingo, Mega-Bug*, Skiing (w/ manual), Typing Tutor, Videotex

     

    Non-working Carts (might just need to be cleaned or might not be compatible with a 64K CoCo2):

    Canyon Climber, Dino Wars (w/ manual), Gomoku/Renju, Microbes, Reactiod, Spidercide, Temple of Rom

     

    Also have the original box and cartridge storage display - but these are bulky so will increase the cost of shipping.

     

    I suspect there's very little of value (and if there is - don't tell me).  But if anyone is interested in the lot please send me a PM.

    Price: C$50 OBO + shipping or meet near Markham

     

    * IMHO two of the best CoCo cart games

    SOLD! two six switchers + controllers & carts

    in Buy, Sell, and Trade

    Posted · Edited by EricBall

    Clearing out the basement and have the following in need of a good home.

     

    six switch CX-2600 made in Hong Kong "Atari-Wong"

    six switch CX-2600 made in Taiwan for Atari

    2x 2600 joysticks, 2x 7800 joysticks, 2x driving controllers, 1 set of paddles, video touch pad

    three 9V wall warts (5W Telstar, 9W Atari CO10472, 10W Atari CO16353)

     

    Everything is untested because I don't have a switch box!

     

    Carts:

    Adventure, Air-Sea Battle, 2x Asteroids, Baseball, Berzerk, 2x Combat, Decathalon, Dolphin, E.T., Enduro, Frogger, Haunted House, Joust, Maze Craze, Moon Patrol (w/ box), Ms. Pac-Man, Pac-Man, Phoenix, Pitfall!, Pressure Cooker, Space Attack, Space Invaders, Star Master, 2x Star Raiders, Super Challenge Baseball, Tennis, Venture (w/ box), 2x Video Olympics, 2x Video Pinball, Warlords, plus mystery Activison & Coleco carts

     

    I suspect there's very little of value (and if there is - don't tell me).  But if anyone is interested in the lot please send me a PM.

    Price: C$50 OBO + shipping or meet near Markham

     

    New competition (?) The Steam Deck

    in VCS PC-Mode Discussion

    Posted

    First, I am not planning on buying one - I've got too many other ways to spend my discretionary time and $$ on.

     

    But I do wonder who the target market is.  While it is an impressive portable PC at the price point almost everything seems to be a little bit of a compromise.

     

    The CPU is decent, although will likely struggle with modern AAA titles.  The GPU is probably equivalent to a high-end laptop APU - but nowhere near as powerful as a traditional desktop dedicated GPU.  Again, fine if you're playing "casual" or "indie" games rather than Crysis X.

     

    Only 16GB of RAM (I'm assuming shared with the GPU) might be a limitation, but probably not as much as the 64GB of slow storage in the base model.

     

    And as others have pointed out, the low resolution of the display may be an issue as well.  (OTOH, lower resolution typically means higher framerates.)

     

    There's also the issue of what games will be playable.  While Linux versions do exist for many titles, they often aren't quite as good as the Windows versions.  Nor will many games be playable via Proton.  (See https://www.protondb.com/ for lots more info.)

     

    However, one place Valve hasn't skimped is on the controls - although I do wonder how well most games will work "out of the box".

     

    But back to "who is the target market" ?  Probably not the people playing competitive online multiplayer games which dominate the Steam top 10.  And post-COVID will as many people be commuting via public transportation?

    Atari2600 Academic research (reinforcement learning)

    in Atari General

    Posted

    @spaceInvader89

    Which email address did you use for me?  (The old atariage one stopped working years ago.)

     

    But I have no issues with you using the game itself as part of your research.  (That would fall under fair use anyway, but I appreciate you asking first.)

     

    Send me a DM if there's anything in particular you'd like to know about the game which would help you out.  I'm also curious about what particular properties Skeleton+ has which caught your interest.

     

    Just don't use it as AI training for killer robots.

    • Like 5
    • Thanks 1

    7800 assembly "hello world"?

    in Atari 7800 Programming

    Posted

    My technique was to loop through the objects then append the entry to the relevant display list(s).  Just need to store an offset for the end of each list.  But whatever the method you have to transform the Y position to select the correct display list and then the graphics page offset.

    • Like 1

    7800 assembly "hello world"?

    in Atari 7800 Programming

    Posted

    IMHO one of the big challenges of programming the 7800 is the amount of data required to get anything to appear on screen - you need to generate the display lists and the display list list.  And once you get that done you realize it's non-trivial to dynamically generate those display lists efficiently.

    • Like 4

    Pac-Man Collection - 40th Anniversary Edition

    in Atari 7800

    Posted

    Just a note to anyone looking at my sprite data to color mapping post, I really recommend you look at the spreadsheet as it makes it much easier to see how the bit patterns match the the different colors.  (And hopefully allow you to avoid making bad assumptions when designing sprites.)

     

    Also for anyone thinking about using the 320 modes, don't forget that large luma changes between pixels will cause false colors on real hardware (e.g Tower Toppler).

     

    • Like 5
    • Thanks 1

    7800 TIA SFX Library, sound2tia

    in Atari 7800 Programming

    Posted

    Thanks for the nod.

     

    Yeah, the TIA audio generator is pretty limited in what it can create, so trying to use it to duplicate any normal audio is fraught with challenges.  That's one of the reasons I went with the brute force correlation rather than something like the FFT.  (Also given an FFT is just a way of calculating a Discrete Fourier Transform - which is essentially a correlation matrix between the input and the set of sine and cosine waves, I figured I could use the raw TIA waveforms to create a similar correlation matrix.)

     

    Hmm... I wonder if what is required is to find the "closest" TIA waveform - so rather than looking for an exact match / correlation, instead somehow have each TIA waveform represent a range of frequencies.

     

     

    320C/320D may actually have uses?

    in Atari 7800 Programming

    Posted

    5 hours ago, Synthpopalooza said:

    So, just to clarify:

    320D means that even columns get the 3 colors from palette 0 plus background, and odd columns get the 3 colors from palette 4 plus background.  Is that correct?

     

    No.  Whether the 320D sprite uses palette 0 or 4 depends upon P2.  P1 & P0 selects which colors are used for the graphics bit combinations.  You get 3 colors + background & transparent from 2 palettes

     

    5 hours ago, Synthpopalooza said:

    I am also seeing the same in 320C but from across differing palettes.  Is that correct as well?

     

    320C uses C2 from palettes 0-3 or 4-7 depending upon P2.  So you get 4 colors + background & transparent from 2 "palettes".

     

    Note: this is better shown in the spreadsheet as it breaks down the exact pixel colors for each graphics & palette bit combination. 

     

    Don't forget that all 320 modes are subject to color aliasing for adjacent pixels with different Y values.

     

    • Like 1

    Is 320B color flaw present in 320C?

    in Atari 7800 Programming

    Posted

    Awesome! Thanks for the info on this, that'll be extremely helpful for me. Just to clarify though, if Kangaroo mode is turned on, then in 320C I can use 4 solid colors, just no transparency available, right?

     

    320C will allow you 4 colors with transparency. However, the two half pixels are either the same color, transparent or one is the background color.

    • Like 1

    Is 320B color flaw present in 320C?

    in Atari 7800 Programming

    Posted

    You're right. In 320B you can't have both of the two half pixels be C1. 320C doesn't have this issue, but it restricts the two half pixels to be either transparent, the same color, or one be the background color.

     

    You've also inspired me to revisit my sprite data to color mapping post an make it easier to understand and hopefully use.

     

    • Like 3
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