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hackadayofficial.bsky.social
Programming the 6581 Sound Interface Device (SID) with the 6502
Programming the 6581 Sound Interface Device (SID) with the 6502
Hackaday Article
hackaday.com
November 11, 2025 at 6:57 AM
kim-6502.bsky.social
It’s Chuck Peddle’s birthday on November 25th, so get your KIM-1 or other #6502 system ready for a big Show and Tell in his honour.
Chuck Peddle, creator of the 6502
November 11, 2025 at 5:13 PM
masterhit.bsky.social
Spread the word: November 25 is #ChuckPeddleDay — celebrating the engineer behind the legendary MOS 6502 processor, the heart of so many home computers and game consoles of the 80s. 💾🕹️

If you own a machine powered by a 6502, fire it up on that day and share a photo with the hashtag #ChuckPeddleDay
November 11, 2025 at 7:42 PM
hackaday-feed.bsky.social
Programming the 6581 Sound Interface Device (SID) with the 6502
Programming the 6581 Sound Interface Device (SID) with the 6502
Over on YouTube, [Ben Eater] pursues that classic 8-bit sound. In this video, [Ben] integrates the MOS Technology 6581 Sound Interface Device (SID) with his homegrown 6502. The 6581 SID …read more
hackaday.com
November 11, 2025 at 7:00 AM
bywilliamjmeyer.com
Taking my first steps using 6502 Assembly w/ bAtari BASIC. #GameDev update on my #Atari2600 #Homebrew MUTATIS.

youtu.be/0BJplaXuicQ?...
Making Mutatis | My First Minikernel! | Using Assembly with bAtari BASIC
YouTube video by William J. Meyer
youtu.be
November 9, 2025 at 7:10 PM
heos.space
Alright 3rd attempt at learning assembly for the 6502!

We’ll get there eventually 🙏
November 10, 2025 at 8:27 PM
bytemaniacos.com
Tremendîsimo video explicando paso a paso como emular una cpu 6502 en C++.
Emulating a CPU in C++ (6502)
YouTube video by Dave Poo
youtu.be
November 9, 2025 at 8:33 PM
kevedwardsretro.bsky.social
Preparing for the Retro Computing Festival ( Gaming Edition ) 2025 at The Centre for Computing History in Cambridge next weekend. Here's a Visual Code setup that allows me to build 'Galaforce 2' from its original 6502 source code and deploy the game to an emulator on a PC. Simple, quick workflow!
November 7, 2025 at 3:55 PM
markmoxon.bsky.social
For starters, it can run the enhanced Compendium versions of:

* BBC Master 128 Elite

* BBC Micro cassette Elite

* BBC Micro disc Elite

* 6502 Second Processor Elite

* Teletext Elite

(3/8)

elite.bbcelite.com/hacks/elite_...
Elite Compendium - Elite on the 6502
Details of the Elite Compendium, which brings all the best Elite hacks together in four feature-packed discs
elite.bbcelite.com
November 5, 2025 at 7:42 PM
hansotten.bsky.social
The KIM-1 Simulator has seen some small updates, to version 1.5.4 Fresh version at retro.hansotten.nl/6502-sbc/kim...
The behaviour of the TTY/LED keypad switch is now closer to how the real KIM-1 behaves.
KIM-1 Simulator – Retro Computing
retro.hansotten.nl
November 11, 2025 at 1:54 PM
vinscool.bsky.social
For my defense this was literally the first game I've ever coded in 6502 ASM, which was a janky Pong clone.

Still, I was able to make up some sort of CPU Player AI that was just good enough to be able to play the game all by itself, so that's cool!

youtu.be/ic2fayKla-U?...
November 7, 2025 at 3:17 AM
markmoxon.bsky.social
Oh… and it can also run almost all of the original Acornsoft versions:

* BBC Micro cassette Elite

* BBC Micro disc Elite

* BBC Micro sideways RAM Elite

* 6502 Second Processor Elite

It can run Angus Duggan’s epic Elite-A, both standard and co-pro versions.

And all in flicker-free, too.

(7/8)
November 5, 2025 at 7:42 PM
kevedwardsretro.bsky.social
In Blake 7, the flight computer of the Scorpio was in fact powered by an Acorn System 1. 6502 rules the universe!
visitthecave.bsky.social The Cave (Neil) @visitthecave.bsky.social · 9d
Have you ever wondered what the flight computer of the Scorpio was in #Blake7?

Professor Steve Furber lets us in on a little secret.

Full talk coming soon to youtube.com/@theretrocollective
November 3, 2025 at 4:29 PM
fredhikes.bsky.social
This is when the height of technology was the 6502, vastly superior to any CPU or GPU today!
November 7, 2025 at 1:17 AM
1001avventura.bsky.social
Grazie a Ready64 riscopriamo una pubblicazione sugli algoritmi di ordinamento e ricerca in BASIC del Commodore 64 e un libro sul microprocessore 6502. #commodore64 #algorithms #basic
www.youtube.com/watch?v=tTND...
Ordinamento e ricerca in BASIC / Commodore 64
YouTube video by Mille e Una Avventura
www.youtube.com
November 7, 2025 at 5:55 PM
mmeadway.bsky.social
See: "Musical Applications of Microprocessors" by Hal Chamberlain (1980).

Brings back fond memories of counting microsecond clock cycles on a 6502 :-)
November 6, 2025 at 11:13 PM
saxxon.bsky.social
Code running inside the stack page, using JSR to self-modify the currently executing instruction, is one of the most insane things I've been informed you could do on the 6502
sidneycadot, on Github: "The most obscure bug (if you can call it that) was a test case where a JSR instruction was located inside the page 1 stack, and the target address of the JSR is altered as the return address is being pushed. That's a case that's easy to miss without a massive test set :)"
November 5, 2025 at 3:38 PM
niallmacaindriu.bsky.social
ah na seanlaethanta... is mé i mo códóir 6502 assembly tráth dá raibh

www.lemon64.com/game/surfchamp
Surfchamp
Surfchamp is a Commodore 64 water sports game released in 1987 by New Concepts.
www.lemon64.com
November 4, 2025 at 6:27 PM
vinscool.bsky.social
Sometime I like to take look at some of my oldest code and find some of the silliest shit like this one below:
Screenshot of a Text Editor with 6502 ASM code: ;* Check how many times the ball was traded between players, apply a slight velocity boost upon the 16th hit detected ;* Since we want the ball to go faster between players, only the Horizontal Velocity will get a boost check_ball_hitcount lda BALL_HITCOUNT beq check_ball_hitcount_done ; if the value is set to 0, it's too early to process, skip this subroutine and #$0F ; was there at least 16 hits applied? bne check_ball_hitcount_done ; if there was not enough hits counted yet, skip this subroutine sta BALL_HITCOUNT ; #0 sits in the accumulator otherwise, reset the ball hitcount using it ; lda BALL_H_VELOCITY ; load the ball horizontal velocity to the accumulator first ; bmi ball_hitcount_dec_velocity ; for a negative value, decrement the velocity ; bpl ball_hitcount_inc_velocity ; for a positive value, increment the velocity ;ball_hitcount_dec_velocity ; dec BALL_H_VELOCITY ; decrement the velocity for 1 unit ; bmi check_ball_hitcount_done ; unconditional ;ball_hitcount_inc_velocity inc BALL_H_VELOCITY ; increment the velocity for 1 unit check_ball_hitcount_done rts ;-----------------
November 7, 2025 at 2:47 AM
suitti.bsky.social
BASIC for 8080, 6502, 6800, & other "8 bit" microcontrollers all used 8 byte BCD floating point. Decoding for printing is easy. Feels like integers. 64 bit binary floating point should give you 14 digits. Feels like integers until you convert to decimal for printing.
November 4, 2025 at 12:50 AM
rasto1968.bsky.social
Another first for me - particle systems :) I wanted to see what the player jets would look like with particles instead of cycling sprites so used my dev system to try particles out. This is displaying a maximum of 16 particles at a time, I like the effect but wonder if it will be possible in 6502..
November 1, 2025 at 7:25 PM
jibe.bsky.social
Since Mortal Kombat Legacy Kollection is out, I shall share an interview I did last year with Antony Hartley, programmer of the infamous and often overlooked Game Boy version of the very first Mortal Kombat (wink @digitaleclipse.bsky.social @noobde.bsky.social @kohler.bsky.social) 1/3
1. Hello Mr Hartley! Can you introduce yourself? I’m a self-taught (an autodidact) who began programming in assembly language when I was just 11 years old. By the time he turned 14, I had my first games published, at the age of 16, I was already a full-time software engineer. I wrote 26 released game SKU’s in a 12 year period. 2. How have you started your career as a game developer? My Grandad was an electronic designer at Decca Navigator, he designed Concordes navigation computer, and he built me my first computer, so I learned to program 6502 code using hex with just 256 bytes of ram. I phone up some local software companies and told them what I had written, they asked me if I could write games for them, so I did. 3. How did you happened to work on Mortal Kombat? What was your role in this development team? I was an independent subcontractor, I had done a lot of work with Probe Software, I was paid about 2000 pounds a week and I had a small royalty in my contract (25p per unit). I was the team mostly, there was a producer “Gary Liddon” who helped me schedule stuff, he also wrote a C program that extracted the original graphics from the arcade machine source code, we all got the full source machine source code, we all got the full source code from Ed Boon at Williams, we had all the assets from the arcade machine, including all the original digital camera images of the martial artist/dancers. I wrote a piece of software that took the original images and converted them, this was an editor / converter that automatically converted all the graphics, it also processed and compressed everything into a number of ROM bank images. Allister Brimble (allisterbrimble.com) did the music using a music engine that was started by Jerone Tel and updated and finished by me. Eric Bailey did some character backgrounds for gameplay and menus like attract mode/start screen/plater select screens/etc, he tidied up and optimized the originals. (Eric was a super cool guy) 4. Did you know about the Mortal Kombat franchise before working on it? It was just released in the arcade, we pretty much got the cabinet when it was released. it was controversial, but only a month old. 5. Did you had any specific instructions for developing this game? Not really, although I would chat with Gary about stuff, although Ed and John had final approval of the finished game. 6. Have you developed a Game Boy game prior to Mortal Kombat? No, it was my first GB game, BTW, I built my own development system for the GB, because I didn’t want to spend 5000 pounds on the Nintendo system. I had worked on Sega Master System and Game gear though. 7. Because of its limitations, did you have any concern about developing a fighting game on Game Boy? Was there any challenge? Many, The game was completely rewritten in GB80, which has no relation to the TMS32010 processor of the original, Ed’s version was massive, my version was ~64x smaller. I wanted to keep the players large, so I used some tricks to do that, the game ended up a little slower, but I felt that it looked better and still played well. I don’t like fighting games with tiny characters, it looks silly. I had to rewrite the whole thing to make it fit. The AI was pretty difficult to do, it was a redesign, but I used some of Ed’s ideas. 8. How much time did you spend on developing the GB version, from beginning to end? Started about November 1992 and was finished in mid-June 1993. 9. The graphics are one of the highlights of Mortal Kombat on Game Boy, especially the big detailed characters sprites. How did you managed to achieve that? It wasn’t possible, the Gameboy doesn’t have big sprites, but I broke the laws of physics. No, I used GB hardware sprites at the edges of the characters and background characters in the middle of the sprites, I cheated, but it costs some processor power to redraw backgrounds. 10. Did the members of the original team (Tobias, Boon, Vogel, Forden) had a look at the game, did approved things or were involved in any way ? What was their feedback? I never heard of Vogel & Forden, perhaps they did sound and other stuff. Ed & John had approval, they said can you make it faster, so I explained, you can have tiny characters or it can run a little slower. They wanted big! 11. You have developed the very first modern fighting game on Game Boy, a system that would receive a surprisingly high amount of fighting games during its long life span. Have you played any other game of this kind on Game Boy later on (MKII and 3, Street Fighter II, Killer Instinct, King of
November 6, 2025 at 9:49 PM
patricktcoakley.com
The 6502 portion of my WIP Apple II emulator seems to be passing some standard test suites so the next step is to get some text on a screen. I think if I can get a BASIC prompt working this month I’d be pretty happy with my progress. Would also be neat to get 65C02 support and try the Lynx out.
November 2, 2025 at 3:02 AM
mindoffrankestein.bsky.social
Yes, I have made some use of tts. Long ago we had Linux systems that booted with a dectalk serial box and was usable by a fully sightless person at the AFB, but they abandoned that and other work under pressure from a donor. My first computer was a Kim-1.
Kim-1 6502 micro
November 1, 2025 at 10:22 AM
swiftyshq.critter.cafe.ap.brid.gy
rough doodle of @sterophonick 's fursona :neofox_w_:

#art #furry
a colored pencil and ink drawing of a white cat with red and blue stripes on his limbs and tail. he is wearing a blue cap with '6501' on it, a red coat, and blue shorts. he is saying 'bleh' and is labeled 'gay' with an arrow pointing at him
November 1, 2025 at 1:33 AM