In Neuromancer, Gibson uses the terms Hosaka, Ono-Sendai, and "deck" interchangeably. The Ono-Sendai is a "matrix simulator" and the Hosaka is a computer. The "deck" is slang for one of the items, but which one? Does one use both machines to access the matrix or are they independent of each other?
The "Ono-Sendai Cyberspace 7" is the I/O peripheral that Case uses to interface (it sounds like a form of direct neural stimulation) with various computers. He carries it with him, and uses it to interface with other computers as well as the Hosaka. (Basically a VR/telepresence rig that you can operate by thinking at it.)
"Case, you want the fifth socket from the left, top panel. There's adaptor plugs in the cabinet under the console. Needs Ono-Sendai twenty-point into Hitachi forty."
The "Hosaka" is more of a traditional computer, though still more powerful than today's, and voice-activated. In the text it is sometimes used as a brand, and other times used as a generic trademark (like "kleenex" for facial tissue):
[...] next year's most expensive Hosaka computer;
"Panther Moderns," he said to the Hosaka, removing the trodes. "Five minute precis."
"Ready," the computer said.
Other computers in the story are also referred to using the "Hosaka" generic/brand name:
"Got your boss on hold," the Flatline said. "He's coming through on the twin Hosaka in that boat upstairs, the one that's riding us piggy-back. Called the Haniwa."
"Deck" seems to be a generic term for an I/O peripheral (what the Ono-Sendai is):
With his deck waiting, back in the loft, an Ono-Sendai Cyberspace 7.
In addition to a cyberspace deck, the text refers to "simstim deck," "matrix deck" (an obsolete military device) and "navigation deck."
Corto was using the Haniwa's navigation deck to link with the Hosaka in Marcus Garvey.
There aren't any descriptions of navigation and matrix decks, but a simstim deck is also a brain-stimulation device:
Cowboys didn't get into simstim, he thought, because it was basically a meat toy. He knew that the trodes he used and the little plastic tiara dangling from a simstim deck were basically the same [...]
("trodes" is almost definitely derived from "electrodes" by clipping though they may no longer actually be electrodes as we understand them.)
The Ono-Sendai and the Hosaka are used together to access the matrix; the Hosaka does the processing and data-transfers, and the Ono-Sendai does the visualizations.