iiinova — where your digital self keeps evolving

Finding a real PET is hard these days. And expense. And it takes up a LOT of space (we had larger desks in the olden days). Here is a meticulously recreated PET in kit form. You could always build yourself a PET-style case to house it.

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Tynemouth Software @tynemouthsoftware.co.uk · 3h

OK, let's do this. New batch of Mini PET 40/80s stand alone with keyboard. Shipping worldwide end of November. Pre-order now £450 kit / £500 built. PET compatible, 40/80 col, 32K, File Browser. PayPal link for US / EU www.paypal.com/ncp/payment/... Contact me for UK and elsewhere or specific quote.

paypal.com

Mini PET 40/80 V1.84 with keyboard

Mini PET 40/80 V1.84 PET compatible 40 / 80 column 32K RAM, BASIC 1/2/4/4.1 Built-in file browser. Shipping late November 2026

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KIM-1 @kim-6502.bsky.social · 4h

The 6502 disassembler at masswerk.at auto-generates labels for jump targets and branch destinations. Feed it raw hex bytes and it gives you readable source. Add a symbol table for named addresses. It even adds cycle counts per instruction.

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OldTechAdverts @oldtechadverts.bsky.social · 10h

Commander Magazine Issure 15 March 1984 #retrocomputing #c64 #commodore64

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Peter Gordon 🇺🇦 @gordon.plus · 13/10/2026

I grew up with the 6502 (acorn electron, oric atmos, c64), then later wrote Z80 code for a living, and recently wrote demos for the Oric Atmos, so I feel I'm qualified to say that, yes, a 1MHz 6502 and a 3.5MHz Z80 will feel about the same speed all things being equal. Comparing 8bit computers...

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Paul [Atreides] Wood @retroid.bsky.social · 12/10/2026

Maybe there's something in that stuff I read years ago about 6502 being more efficient per clock cycle than the Z80 if this is what a 1MHz C64 can do versus a 4MHz CPC

youtube.com

Commodore 64 Raycasting with variable ceiling and floor heights

YouTube video by piotoor_dev

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KIM-1 @kim-6502.bsky.social · 13/10/2026

Every true computer veteran had a system with terrible keys.

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KIM-1 @kim-6502.bsky.social · 13/10/2026

The masswerk.at PET 2001 emulator is cycle-accurate - CPU, video, and audio all tick in sync. It runs BASIC 1, 2, and 4 ROMs, handles D64 disk images, and even emulates the original chiclet keyboard. Drag and drop a .prg file to run it.

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KIM-1 @kim-6502.bsky.social · 12/10/2026

The forthcoming 800XL at the Portland Retro Game Expo. Real keyboard, cartridge slot, USB joysticks, built-in games, 80s style. Nice! Also spotted some original hardware and some Atari prototypes. #PRGE

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KIM-1 @kim-6502.bsky.social · 12/10/2026

Branch instructions on the 6502 used signed 8-bit offsets: -128 to +127 bytes from the next instruction. Cross a page boundary and it costs an extra cycle. Stay within the page and branches are fast. Code layout was a performance decision.

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KIM-1 @kim-6502.bsky.social · 12/10/2026

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Tynemouth Software @tynemouthsoftware.co.uk · 11/10/2026

New Blog Post - VIC20 Bunny Blitz - blog.tynemouthsoftware.co.uk/2026/10/vic2... I have rewritten an old VIC20 BASIC game, Rabbit Blitz by C.Simun in 6502 assembler to fix a couple of bugs and add a few new features and a general spruce up. Source and binary on github - github.com/tynemouthsof...

Rabbit Blitz title (with ££££££££ bug showing)

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KIM-1 @kim-6502.bsky.social · 11/10/2026

The 6502 used little-endian byte order. Address $1234 was stored as $34 $12 in memory. The MOS documentation wrote addresses as $LLHH in machine code but $HHLL in assembly. As masswerk.at puts it: the assembler uses human-readable big-endian notation.

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KIM-1 @kim-6502.bsky.social · 10/10/2026

BRK on the 6502 was a software interrupt. It pushed the PC and status register to the stack, set the Break flag, then jumped through the IRQ vector at $FFFE. One byte to enter the monitor. The KIM-1 used it as its primary debugging tool.

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Bill Loguidice @billloguidice.bsky.social · 09/10/2026

THEA1200 game list: All 25 games for the modern Commodore Amiga 1200 recreation Explore the complete 25-game list included with the THEA1200, a modern, plug-and-play recreation of the classic Commodore Amiga 1200. Discover which beloved titles and hardware accessories come right in the box.

armchairarcade.com

THEA1200 game list: All 25 games for the modern Commodore Amiga 1200 recreation

Explore the complete 25-game list included with the THEA1200, a modern, plug-and-play recreation of the classic Commodore Amiga 1200. Discover which beloved titles and hardware accessories come right in the box.

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SolderDemon @solderdemon.bsky.social · 09/10/2026

I'm putting the finishing touches on a new written assembly guide for the rosco_m68k ecosystem. At the same time, I'm preparing to move beyond rosco_m68k and introduce SolderDemon's own m68k and 6502 product lines. More to come!

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KIM-1 @kim-6502.bsky.social · 09/10/2026

The 6502 assembler at masswerk.at accepts almost any syntax style - MOS notation, modern conventions, BBC Micro format. It even handles the Acorn Atom @ prefix for immediate mode. A universal translator for 6502 dialects.

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Atari @atari.com · 08/10/2026

Your very first computer is back. 🖥️ We're happy to report the 800XL includes a full-sized mechanical keyboard and working cartridge slot. Plus, we added features designed for today’s televisions and gaming setups. 🤝 Learn more: atari.com/800xl

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KIM-1 @kim-6502.bsky.social · 08/10/2026

Zero page addressing on the 6502 saved one byte and one cycle per instruction. LDA $00FF is two bytes. LDA $0200 is three. When your entire program fits in 2K, that extra byte per instruction adds up fast.

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JLSoryu @jlsoryu.bsky.social · 07/10/2026

Woolworths is the obvious one I miss, just because of how prominent it was but I just miss having that variety in tech/gaming on the high street in general. Missing being able to go for a nice browse. I do have a soft spot for Maplin, not as a shopper but because that was my first job!

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KIM-1 @kim-6502.bsky.social · 06/10/2026

The 6502 JMP indirect bug: JMP ($10FF) fetches the low byte from $10FF and the high byte from $1000 - not $1100. The page boundary wraps. masswerk.at notes the 65C02 fixed this, fetching correctly across pages.

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KIM-1 @kim-6502.bsky.social · 06/10/2026

Hans Otten has translated some period Dutch KIM-1 magazine articles into English. Enjoy! retro.hansotten.nl/radio-bullet...

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KIM-1 @kim-6502.bsky.social · 05/10/2026

The 6502 status register packed 7 flags into one byte: Negative, Overflow, Break, Decimal, Interrupt disable, Zero, and Carry. Bit 5 was unused and always read as 1. PHP pushed all of them at once. PLP restored them. Two bytes for a complete context switch.

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Tynemouth Software @tynemouthsoftware.co.uk · 04/10/2026

New blog post - Find out how I managed to squeeze even more games into the latest update to the Penultimate Cartridge, and made it easier to use in the process. blog.tynemouthsoftware.co.uk/2026/10/penu...

Penultimate +3 DCR. Did I mention it has a built in SD2IEC drive???

Misfits Gravzronox (handy the name is written at the top of the screen or I would never be able to spell it)

Timebomb reloaded, by some guy called Dave?

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KIM-1 @kim-6502.bsky.social · 04/10/2026

Early 6502 chips had a bug in the ROR instruction. Before June 1976, ROR behaved like ASL but shifted in zero and ignored the carry flag. MOS quietly fixed it without announcing the change. masswerk.at even lets you toggle this bug in their emulator.

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ChipWits & ChipWits Worlds 🤖 Available on Steam! @chipwits.bsky.social · 01/10/2026

🛠️ ChipWits Worlds Devlog: The Commodore 64 Programmer's Reference Guide was my programming bible growing up. I wanted to capture that exact feeling for our in-game manual while writing 6502 assembly for your robots! #RetroComputing #C64 #GameDev #DevLog

Side-by-side comparison: the physical 1982 Commodore 64 Programmer's Reference Guide next to the ChipWits Worlds in-game 65C02 manual, assembly code editor, and 3D robot.

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Zoë H @zoeswipe.bsky.social · 02/10/2026

Had a funny conversation the other day with someone who was reliant on Claude to do *anything*, and their mind was blown in disbelief when I said I could write code with nothing more than a basic text editor or compiler. Or if I'm feeling really spicy, a 6502 or Z80 assembler.

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bflmouse.bsky.social @bflmouse.bsky.social · 02/10/2026

Personally, I knew the undocumented instructions were there, but never bothered to use them. The rare case where one of them was useful to me was more than outweighed by the hassle of getting my assembler to accept them.

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Simon Harris @simondo65.bsky.social · 02/10/2026

How widespread was the use of the unofficial instructions? Personally I never used them as I like to stay within the bounds of the datasheet,and after a few years of the NMOS 6502,I moved on to the 65C02 where many of those opcodes became documented new instructions and extensions of the originals.

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KIM-1 @kim-6502.bsky.social · 02/10/2026

The 6502 had 56 official instructions across 151 valid opcodes. The remaining 105 byte values were undefined - but not empty. They triggered unpredictable combinations of the real instructions. masswerk.at documents all of them with full cycle counts and flag behavior.

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KIM-1 @kim-6502.bsky.social · 01/10/2026

Those are controversial?

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Andy Hewco @hewco.uk · 01/10/2026

New version of 8bit Pixel Lab for creating graphics and tilemaps for 8bit computer platforms. hewco.itch.io/8bit-pixel-lab New in this version are C64 sprites, Gameboy/Colour and sprites and now five BBC/Electron graphics modes. Also supports Vic 20, C64, Amstrad CPC and Spectrum.

hewco.itch.io

8bit Pixel Lab - Windows, Mac & Linux by Hewco

Create Character map and Tile map graphics for the Vic 20

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GrantMeStrength @grantmestrength.bsky.social · 01/10/2026

Now on TestFlight. Ready to pad out your resume with the hottest 5th generation language? testflight.apple.com/join/uSKD5zEt

Home page of a prolog app. An artificial drawing of a landscape image and a list of topics.

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GrantMeStrength @grantmestrength.bsky.social · 30/09/2026

Latest release of the (free) Retro Computer app includes links to 3rd party emulators - you can read about a system and then use it right on your phone/ipad! apps.apple.com/us/app/retro...

Page from the app showing a 3D model of an Apple IIe and links to emulators.

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bflmouse.bsky.social @bflmouse.bsky.social · 29/09/2026

Apple IIgs. I have one, and I still have some of the development software from back in the 1980s.

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Tynemouth Software @tynemouthsoftware.co.uk · 30/09/2026

A text editor and a command line assembler. Because that's the way I have been doing it since the 80s.

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hansotten.bsky.social @hansotten.bsky.social · 30/09/2026

the KIM-1 Simulator, Notepad++ and comnand line interpreter. Edit, assemble with one click, load code in Simulator and run and debug with symbol table from assembler.

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KIM-1 @kim-6502.bsky.social · 29/09/2026

What is your fav 6502 development platform and why?

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8bitworkshop @8bitworkshop.bsky.social · 29/09/2026

VS Code users: 8bitworkshop now has a preview extension, providing your favorite compilers and emulators in the comfort of your desktop. There are probably a lot of rough edges (and for me the classic IDE is simpler to use) but give it a shot! marketplace.visualstudio.com/items?itemNa...

marketplace.visualstudio.com

8bitworkshop — Retro 8-bit Dev - Visual Studio Marketplace

Extension for Visual Studio Code - Build, run, and debug 8-bit programs — NES, Atari, C-64, and more — with 8bitworkshop's 6502/Z80/6809 assemblers, compilers, and emulators

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smymy_128 @smymy-128.bsky.social · 29/09/2026

colorful conway's game of life simulation i made on skilldrick's 6502 emulator i did this in a hurry, so there's a lot i still have to optimize, but i'm not going to do this now and at least i can put custom rules, #65o2 or #6502 idk

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Zenith @zencorner.xyz · 29/09/2026

6502 is fun and also ow my brain

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Rue Mohr @ruenahcmohr.bsky.social · 29/09/2026

oof, why dont they make 8 bit synchronous counters right? Can you use a high-speed 6502 locked into a LDA cycle? hmm, I suppose not, no reset... The compare are a few less parts if you stick strictly to LS of course... Where is even/odd field?...

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