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(This is an experimental, work in progress, recovery of the visual6502 wiki content from the Internet Archive's Wayback Machine. See the archive copy for preference.)

Main Page

Welcome to the visualchips wiki. Please see also the visual6502.org site which contains the backstory, useful links, a FAQ, and a link to the project blog. We're all about reverse-engineering popular chips from the 70's and 80's - initially the 6502 but others too. This wiki is for documenting our findings and recording our sources, and is of course a work in progress. The online help for our JavaScript simulator is also here, to help you get the most from that. (Note that it's only a switch-level simulator - our data also supports more accurate models. For most purposes, there's no difference.) For help on reading the layout, interpreting transistor circuits, and more about digital design, please see the Visual Circuit Tutorial over at NESdev.

To navigate this wiki, please see

• the Full index
• Popular pages

Projects and status

Here's the state of play of the chips we're most actively working on. (See also the wiki index for exploration.)

• Motorola 6800 CPU: Breaking news! The Visual 6800 JavaScript simulator is now live. See Motorola 6800 for notes on the implementation of this chip, and the relationship to 6502.

• MOS 6502 CPU: Our flagship project: we have several pages of findings and many pointers to other resources. We started from photos and now have a full transistor level netlist with transistor sizes, and of course our in-browser simulator.

• Atari 10444D TIA (Television Interface Adaptor): fully extracted and simulated, no data yet published.

  • Pictures and story on our main site.

• Atari ANTIC: layout is in the process of polygon capture or netlist extraction.
  Primary data not yet published, but see these threads.

• Zilog Z80 CPU: We have photographs of the metal layer, and have started capturing the polygons. No public information yet.

• Motorola 68000: We have photographs of the metal layer, and have started capturing the polygons.
  The project page contains die photo and shows areas being captured. This chip will need further deprocessing and photography for the lower layers.

• RCA 1802E space-faring radiation-hard CPU: pictures and story on our main site.

• MOS 6522 VIA: pictures and story on our main site.

• Nintendo 3193A support chip pictures and story on our main site.

• Commodore 8580 SID: pictures and story on our main site.

  • Also being analysed elsewhere

• Sinclair Spectrum ULA: photographed, circuit manually captured, original sources not presently public.
  See Chris Smith's excellent book for ULA background and lots of detail about the Spectrum ULA

• Acorn Electron ULA: photographed and stitched, nothing online yet

• Acorn Tube ULA: we have a 'spare' chip, decapsulated and ready for microphotography

More chips

We have a number of other chips, including some generous donations, all in the queue to be reverse engineered:

• Chips in our collection tabulates the chips, indicates how far we've got with each, and links to images as appropriate.
• Other Chip Image Sites contains links to other similar projects. See also John McMaster's list.
• Original high-resolution stitches, as well as the original chip photos, can be found on our stitch repository.

If you have other historic chips, we're interested in donations! Please also see the donations status page on our main website.

Contributing to this wiki

Please see our policy page before making contributions