Atari XL/XE Forum — Games, Hardware, Homebrew | 6502ish
The Atari XL and XE lines are the 1983-and-later refinements of the 400/800 architecture Atari launched in 1979. Same custom chips, cleaner industrial design, and enough of a community that people are still shipping new games on cartridge in 2026.
Inside the machine: MOS 6502C ("Sally") at 1.79 MHz NTSC (1.773 MHz PAL), 64 KB of RAM on the 600XL/800XL/65XE, 128 KB on the 130XE via PortB bank switching. The custom silicon is what makes these machines interesting — ANTIC runs a programmable display list, a per-scanline graphics coprocessor that predated everything else on the home market; GTIA generates the pixels (256 colors via PAL/NTSC artifacting, four players + four missiles for sprites, raster interrupts); POKEY handles sound, keyboard scanning, and the SIO serial bus all in one chip.
What the community works on:
- Games — the original catalog is about 2,500 commercial titles, and the homebrew pipeline coming out of ABBUC and Silly Venture hasn't slowed. Classics that still play well in 2026: Star Raiders, M.U.L.E., Rescue on Fractalus, The Eidolon, Alternate Reality: The City. The Atari 8-bit port of Pitfall II has two extra levels the other platforms didn't get.
- Hardware — recapping XL power boards, replacing failure-prone GTIAs, U1MB / SIDE3 / Incognito internal upgrades, AVGCart and SDrive-MAX for modern storage, FujiNet for Wi-Fi + virtual PBI peripherals.
- Programming — MADS and MAC/65 are the working assemblers. Action! (the compiled language by Clinton Parker, OSS) was re-released as freeware and still produces fast code. Turbo BASIC XL is the BASIC you actually want over the shipped Atari BASIC Rev. C. cc65 works; a modern Oscar64-equivalent doesn't exist yet for the 8-bit Ataris.
- Music — POKEY has four voices, square-wave only, but with a 17-bit precision mode when two channels are paired. RMT (Raster Music Tracker) is the standard composition tool; the POKEY tune archive is small next to HVSC but tight.
- Demoscene — ABBUC runs an annual software contest that's been going since 1986. Silly Venture (Gdańsk) is the big Atari 8-bit demo party; recent editions still pull first-release hardware and software from active groups.
- Preservation — ATR (disk), XEX (DOS executable), and CAR/BIN (cartridge) dumps are well-covered. Homesoft and AtariMania host most of the canonical archive.
Buying one: 800XL is the sweet spot — working units run $80–180 on eBay depending on cosmetics. 130XE is the upgrade target ($150–300) for its 128K bank switch. Budget $30 for a modern SIO power brick; the originals are 40-year-old linear units and a few have failed in ways that took the motherboard with them. A 1050 or Happy-modified 1050 is the period-correct disk drive, but everyone ends up with an SDrive-MAX or AVGCart eventually.
Getting started cheap: Altirra is the reference emulator — Avery Lee has been developing it since 2008, it's cycle-accurate down to the scanline, supports every official memory configuration and most of the unofficial ones, and its debugger/profiler is arguably the best on any retro platform. atari800 is the cross-platform fallback when you're not on Windows. Our Atari XL/XE file exchange has ATR disks and XEX programs; the forum is where hardware questions land.
Frequently Asked Questions
What Atari 8-bit emulator should I use in 2026?
Altirra on Windows. Avery Lee has been developing it since 2008, it's cycle-accurate down to the scanline, supports every official memory configuration and most of the unofficial ones, and its debugger/profiler is arguably the best debugger on any retro platform full stop.
Cross-platform: atari800 is the fallback (macOS and Linux). Browser: a few atari800 WebAssembly builds exist but lag Altirra on accuracy — use them for quick inspection, not for playing anything finicky.
Skip Atari++ — development stopped years ago and it never caught up on SIO timing.
XL vs XE — does it matter?
Functionally very little for most software. The line-up:
- 600XL (1983) — 16K RAM; skip unless it has a period or modern 64K upgrade.
- 800XL (1983) — 64K, the default target; most of the catalog was written with this in mind.
- 1200XL (1982) — rare, nice keyboard, some compatibility issues with later XL-era software because of its OS revision.
- 65XE (1985) — 64K, European-first redesign, same internals as the 800XL in a different case.
- 130XE (1985) — 128K via PortB bank switching; the upgrade target. "XE-enhanced" software targets this and won't run right on a 64K machine.
- 800XE (1986, Europe) — a 130XE case with only 64K inside. Buyer's trap.
If you're buying one: 800XL for everything, 130XE if you want the bank-switched titles.
ATR vs XEX vs CAR — what do I load which way?
- .ATR is a disk image — boot as drive 1 in the emulator, or stage it through an SIO2SD / SDrive-MAX / FujiNet on real hardware.
- .XEX (sometimes .COM) is a DOS executable — emulators let you "run executable" and they stage it via a synthetic boot disk internally. On real hardware you need a DOS (MyDOS, SpartaDOS X) and you
RUNit. - .CAR / .ROM / .BIN is a cartridge image. Some tools need a CART header in front of the raw ROM so the emulator knows whether it's 8K standard, 16K, XEGS, bankswitched, etc. Altirra and atari800 both prompt for the cart type if the header's missing.
On real hardware: AVGCart handles all three formats in one cartridge; FujiNet handles ATR + XEX over the network.
Why doesn't my Atari BASIC program work right?
Probably Atari BASIC Rev. B's LIST/ENTER bug. The shipped BASIC on early 600XL and 800XL units corrupts LISTed programs in subtle ways that only surface when you re-ENTER them later.
Rev. C (fixed) shipped on later XL/XE machines and is bundled in most aftermarket OS ROM images. Check yours: ? PEEK(43234) returns 234 on Rev. C.
Fix options: flash a Rev. C ROM, run Altirra with the Rev. C ROM selected, or skip the shipped BASIC entirely and use Turbo BASIC XL — faster, more features, fully compatible, still actively used.
SIO2SD vs AVGCart vs FujiNet — which modern storage?
- SDrive-MAX — cheapest entry (~$25 kit, free if you build your own on an Arduino). Presents as a stack of emulated 810/1050 drives fed from an SD card. Great for ATRs, nothing else.
- AVGCart — cartridge form-factor; loads CAR, ATR, and XEX from an SD card. If cartridges are the bulk of what you want to play, start here.
- FujiNet — Wi-Fi + TNFS network filesystems + virtual printer + modem emulation + PLATO/BBS clients. Still under active development by the FujiNet team.
If you only buy one and you have Wi-Fi in the room: FujiNet. It subsumes everything SDrive-MAX does and adds the network side.
Can I play Atari XL/XE games on 6502ish in the browser?
The <strong>/games/atari8</strong> shelf is live for browsing and admin uploads — but in-browser play is still parked. EmulatorJS doesn't yet ship an <code>atari800_libretro.wasm</code> on its CDN, and the libretro buildbot only publishes whole-RetroArch 7z bundles, so the core has to come from a local emscripten build. The shelf will light up the Play button automatically as soon as an <code>atari800_libretro.wasm</code> lands in <code>public/assets/emulatorjs/cores/</code>. In the meantime, download the ATR / XEX / CAR you want from the <a href="/files/atari-xlxe">file exchange</a> and run it in Altirra or atari800 locally.
