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The Desk & Breadboards

The desk is Chip Hippo's infinite, pannable, zoomable workspace — the place every board, chip, wire, and power source lives. This page covers how to move around the desk and how breadboards actually work under the hood: they are not single parts but individual strips — a pin-board plus power rails — that snap and mate together the way real boards do on a bench.

A Full 830 breadboard on the desk, with a spare power rail turned on end beside it

Pan, zoom & fit to screen

The desk has no edges — pan and zoom to work at whatever scale suits the circuit in front of you.

A faint dot grid marks the 0.1 in hole pitch under everything you place; it coarsens at low zoom and disappears entirely once you're zoomed out too far for individual holes to matter. Zoom and pan position are remembered between sessions.

The desk padlock

A padlock sits in the desk's top-right corner, across from the tab strip. Click it (or press Cmd/Ctrl+L) to shut it, and the scroll wheel stops reaching the desk.

It exists for one input in particular. A Magic Mouse — and some trackpads — reports a scroll from a finger merely resting on the surface, so the wheel is the one thing that moves the desk without being asked to; midway through seating a chip, that's a circuit that slides out from under you. Everything else still works while it's locked: Space-drag and middle-drag panning, the zoom cluster, the keyboard shortcuts above, and Fit. It's the wheel that's locked, not the camera.

The padlock's shape changes rather than just its colour — an open shackle when the wheel is live, a shut one when it isn't. It's saved with the project: shut it, save, and the project reopens with the wheel still locked. Because it's part of the file, changing it counts as an unsaved change, like renaming a desktop. A new project starts with it open. The schematic view has a wheel of its own and no padlock over it.

Breadboards are strips

A real solderless breadboard is not one molded part — it's a centre pin-board with one or two power-rail strips dovetailed onto its top and bottom edges. Chip Hippo models this literally: each strip is its own object on the desk, and what looks like "a breadboard" is a small kit of strips placed together in one action.

The palette offers three assembled kits:

On a pin-board, rows run top to bottom as j i h g f, then the trench, then e d c b a. The trench is the gap down the centre that isolates the top half of each column from the bottom half electrically — a DIP chip straddles the trench, with one row of pins in f and the other in e (or, for the wide 600-mil chips, in two rows six holes apart — h and d, say), exactly as it would seat on a real board. A power-rail strip carries both a + and a − line, each one continuous connection along its whole length, independent of every other strip.

See Chips & Components for how chips and discretes seat into the grid, and Power & Clock Sources for feeding a rail from a PSU.

Kits vs. loose strips

Below the assembled kits, the palette also offers the individual strips on their own — a bare Full pin-board, a bare Half pin-board, a spare Full power rail, a spare Half power rail, and a Split power rail. Reach for these when a board shipped without enough rails, when you want a rail somewhere a kit wouldn't put one, or when you're building up a custom layout strip by strip. Placing, ghosting, and overlap checking all work identically whether you're dropping a whole kit or a single loose strip.

The split power rail

A Split power rail is a full-length rail with both of its lines cut in the middle, like the boards sold for circuits that need two supplies. Holes 1–25 and 26–50 of each line are separate connections, and the printed red and blue stripes break at the cut so you can see where it is. Each half can take its own supply — 5 V for the 74LS chips on the left, 9 V for the CD4000 chips on the right, say — and its own net name. It dovetails, turns, and seats exactly like a Full power rail.

Jumpering the two − halves together is fine (two supplies normally share a ground). Jumpering the two + halves together is not: two supplies set to different voltages would then fight over one net, and the simulation reports it as a fault (see Power & Clock Sources).

Snapping & mating

Drop a strip within a couple of tenths of an inch of another strip it can dovetail with — matching width when stacked, matching height side by side, meeting flush with no gap — and it snaps into place automatically. This is the same magnetic pull whether you're dragging a placed strip or holding a fresh one from the palette; a whole kit snaps as one piece, and the pull only ever engages when the snapped position is still legal (it will never pull a strip into an illegal overlap).

Two strips that end up flush mate: they join a shared group and from then on drag together as one rigid unit, just like a real breadboard's rails stay attached to its pin-board when you nudge it on the bench. A kit arrives pre-grouped; anything you drop flush against an existing board joins its group (or merges two groups into one, if it bridges a gap). When several strips are mated, Cmd/Ctrl-clicking any one of them selects the whole set — the outline traces the union of the group's strips, so flush neighbours read as one board rather than showing a seam between them.

Selecting things

Every press on the desk follows one rule: a click is just a drag that didn't go anywhere. Press on something and you've picked it up; let go in the same place and it's set back down where it was — and the one thing that's changed is that it's now selected, with everything else let go. Press and move, and you're dragging it. There's nothing to learn about "clicking to select" versus "dragging to move"; the only difference is whether the pointer travelled.

What you press decides the rest:

Several things at once

Cmd/Ctrl-clicking a board takes its whole snapped group. Clicking a bus takes all of its member wires — a bus is bookkeeping over wires, and the wires are what a delete or a copy acts on. Notes, labels, signal flags and picked legs can't join a multi-selection, so Cmd/Ctrl-clicking one does nothing; a plain click still selects it.

On macOS this is Cmd, not Ctrl — the modifier the rest of the platform's lists use. Ctrl-click there is the system's secondary click, and it keeps that job: it still opens an item's context menu.

A board carries its parts

A selected board takes everything seated on it along — its chips and parts, and the wires running wholly on it — as passengers. Passengers ride with the board when you move or delete it, but they aren't selected in their own right, so they aren't highlighted: a highlighted part always means "this part, selected for itself". If you'd already selected some chips and then add their board, the chips drop out of the selection (they'll come along anyway); take the board back out and they stay out — undo is the way back. Pressing a passenger on its own is an ordinary click on it: that part alone becomes the selection.

A box that covers only part of a board doesn't take the board. It takes the parts that are wholly inside the box instead, each selected (and highlighted) on its own.

One leg at a time — Option

Hold Option (Alt on Windows and Linux) and the desk switches to pin targeting: bodies stop reacting, and the only things you can pick are the holes holding a lead that can move on its own — a wire end, a leg of a resistor, LED, capacitor, diode or other two-legged part, or a leg of a TO-92 transistor. Hover over one and its hole rings in red. A chip's pins never light, nor do a TO-220's: a pin can't move apart from its body.

Option-click a red hole and that one lead becomes the whole selection (it never adds to what was selected). Option-drag it to move just that lead to another hole — the other end stays where it is. Delete with a leg picked removes the part (or wire) it belongs to.

A routed wire answers Option too, anywhere along it that isn't an end: Option-drag the run to add a bend there, or a bend to move it — the only way to bend one, since a plain drag moves the whole wire (see Wire layout).

To pick several leads, hold Cmd as well (Alt+Ctrl on Windows and Linux): Option+Cmd-click a red hole adds that lead to the selection, and clicking it again takes it back out. The leads can sit beside parts, wires and boards in the same selection. Then drag — grab one of the ringed holes, or anything else in the selection — and every picked lead moves with it: a wire with one end picked stretches, a resistor or LED with one leg picked bends, and anything whose other end is moving too travels whole. A lead whose wire or part is already selected is covered by it, so picking it again changes nothing. A plain Option-click still starts over with just that one lead.

What a selection does

Delete removes all of it in one go — no questions, and one Cmd/Ctrl+Z brings it all back. A selected board takes its passengers with it, and a wire left with nothing at one end (because that end was in a deleted board, or on a deleted PSU) goes too. Cmd/Ctrl+C copies the selection (as a whole design, if it includes boards — see Projects & Desktops), Esc clears it, and Cmd/Ctrl+A selects the entire desk.

A selection also moves as one. Grab anything in it and the whole set — boards, parts, wires — travels by the same amount, keeping the arrangement you built. The thing under your pointer snaps to the hole grid and everything else follows exactly. Wiring comes along: a wire with both ends on what's moving moves with it, and a wire with one end left behind stretches — the moving end follows its part to the new hole and the other stays put, so nothing is quietly disconnected. The drop is all or nothing: if anything in the set can't land (a pin over a taken hole, a board on top of another), the whole selection springs back. Hold Shift as you press to move it bare instead: only what you selected moves, and the wiring plugged into it stays where it is. See Moving several parts at once for the details.

Undo covers your clicks too. Each change of selection is a step in the undo history, so a misclick that threw away a careful selection is one Cmd/Ctrl+Z away from coming back.

Nothing can be selected while the simulation is running — the topology is frozen, so a selection would be one you couldn't act on. (Clicking a wire still highlights it, to trace where it runs.)

Groups & breaking a snap

Moving a selected board moves exactly the strips that are selected. Cmd/Ctrl-clicking a board selects its whole snapped group, so the kit moves as one, just like a real breadboard's rails stay attached to its pin-board.

To pull a strip off its group, select just that strip: draw a box around the pin-board (and its parts) but not the rail beside it, then drag. The strip peels away from the rail left behind, and every wire running between them stretches across the new gap — the connection survives the separation. When you drop it, both the piece you moved and what's left of the group are re-evaluated, each split into fresh groups based on what's still actually mated within it. Dropping strips flush against each other mates them again.

Rotating a rail

Power rails can rotate; pin-boards cannot. A pin-board's trench (and every DIP seated across it) only makes sense in one orientation, so it's locked at 0°. A rail strip is just two parallel lines of holes, so it reads the same standing on end — turned 90° it becomes a vertical signal bus you can run alongside a board and tap into at any point along its length.

Press R while a rail is in hand (mid-placement, before you click it down) to cycle its rotation through 0°/90°/180°/270°. Once a strip is placed its angle is fixed; to change it, pick it up again. Rotating doesn't change anything electrically — a rail is one continuous node however it's turned (each half is, on a split rail) — it only changes which way the strip's footprint runs on the desk.

Next: Chips & Components for populating a board, or Wiring, Nets & Buses for connecting everything up.