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Atari 2600 pixel calculator
A legacy console is not just another HDMI source. The 2600 paints a 160-pixel-wide, roughly 192-line picture meant for a 4:3 television — so the interesting question on a 55-inch flat panel is not "how sharp" but "how large does one source pixel become, and from how far away does that stop looking like a mosaic." This works that out, with the assumptions visible and editable. Built for the 2600 first; the preset list is structured so NES, SNES, Genesis and PS1 can join later.
Source
custom
Active pixels × H × V
160 visible color clocks across; 192 visible scanlines of 262. The canonical North-American 2600 frame. Editable on purpose — there is no single "true" 2600 resolution, only the assumptions you pick.
Display
Diagonal in
Aspect
Scaling
Viewing distance
Displayed image
91 cm (36 in) × 68 cm (27 in)
on a 55″ 16:9 panel, pillarboxed
One source pixel
5.7 mm (0.22 in) wide
3.6 mm (0.14 in) tall
displayed aspect 1.6:1 (intended 1.6:1)
Pixels per degree
7.5 horiz · 12 vert
~8′ per pixel across · 5′ down, at 2.4 m (8 ft)
Field of view
21.2° wide · 16° tall
how much of your vision the picture occupies
"Retina" distance
19.6 m (64.4 ft)
where one pixel shrinks to 1 arcminute (~60 px/°)
Integer-scale fit
11× → 2112 lines
192 × 11 into a 2160-line panel · 2.2% border
- ⓘPillarbox bars about 15 cm (6 in) wide sit down each side. A 4:3 source on a 16:9 panel is supposed to leave them there — resist the Zoom button.
- ⓘAt 2.4 m (8 ft) you resolve about 7.5 of these pixels per degree — well under the ~60 a sharp eye can separate. The blocks are meant to be seen. That is not a fault, that is 1977.
- ⓘOne source pixel lands 5.7 mm (0.22 in) across. To shrink it to a single arcminute you would have to sit 19.6 m (64.4 ft) back — farther than the room, plausibly farther than the building.
- ⓘBy design a 2600 pixel is 1.6× wider than it is tall: non-square, because it was timed to NTSC rather than to a square grid. Any tool that renders it perfectly square is flattering you.
What the numbers assume
- ▸160 pixels across. The TIA chip clocks 228 color clocks per scanline; 68 of them are the horizontal blank while the beam flies back, leaving 160 visible — the machine’s entire horizontal resolution, the same on NTSC, PAL and SECAM.
- ▸~192 visible scanlines (NTSC). An NTSC frame is 262 lines; the canonical 2600 kernel paints 192 of them as picture. PAL stacks 228 visible of 312. So the default frames are 160×192 (NTSC) and 160×228 (PAL) — both editable above, because no program is obliged to use exactly that many lines.
- ▸The frame is 4:3. The 2600 was built for a 4:3 television, so the calculator displays the active picture in a 4:3 area unless you deliberately stretch it. Plug it into a 16:9 panel and the honest result is a pillarboxed 4:3 image with bars down the sides.
- ▸The pixels are not square. 160 wide across a 4:3 frame against 192 tall makes each NTSC pixel about 1.6× wider than tall ((4/3)×(192/160)). That is geometry, not nostalgia. (MAME models the sprite pixel a touch wider still, ~1.71:1, from subcarrier-exact timing; both beat any "square pixel" rendering.)
- ▸Pixel size = picture width ÷ 160. Once the active image’s physical width is known, each source pixel is that width over the horizontal resolution; the vertical pitch is picture height over the line count. A pixel at distance d subtends 2·atan(pitch/2d); pixels-per-degree is the resolution over the picture’s field of view, and the eye separates detail down to roughly one arcminute (~60 px/°).
Sources
- Andrew Davie, “Atari 2600 Programming for Newbies” (Sessions 2, 3, 7) — randomterrain.com (228 color clocks, 68 hblank, 160 visible)
- Atari VCS/2600 NTSC/PAL/SECAM scanline lists — ataricompendium.com / digitpress.com (262/312 total, ~192/228 visible)
- “Atari 2600 hardware” — en.wikipedia.org (160×192 NTSC / 160×228 PAL, 4:3 display)
- MAME / Stella display models and “Data Driven Gamer: Atari 2600 aspect ratios” — non-square pixel aspect (4:3-fill geometric ~1.6:1; subcarrier-exact ~12:7)