Even though sloppy is fine, it might be a bit of a good idea to arrange this particular page because, to be quite frank, as it is right now, it is just absolute garbage.
During the events of Homestuck, John Egbert uses several computing devices to stay in touch with his co-players and the trolls.
John's desktop[]
A rather ordinary looking desktop computer that serves as John's initial computing device. It looks somewhat dated, though modern enough to have a flatscreen monitor. He uses this computer to install Sburb. It was destroyed after an Imp threw it out the window while John was away from his home.
PDA[]
The PDA originally belonged to Dad before it is taken by John along with the red package that Dave sent and the envelope containing John's copy of the Sburb client. John originally takes it with the intention of playing a prank on his father by changing the background to something funny. It is then expelled out of John's Bedroom window when he is experimenting with his new Queue Fetch Modus, and it rockets out to the yard. Rose retrieves it for John using her Sburb server capabilities. Its background is surprisingly not a harlequin but instead a pipe, indicative of John's Dad's decidedly unspectacular fatherly interests. John, while fooling with his Sylladex again, jettisons it out into a neighbor's yard where it is then picked up again in Act 2. However, this time it is on a small and unreachable parcel of land, so Rose builds a bridge to get John close to it. The PDA seems to go through a lot, as it is constantly launched from John's Sylladex or buried underneath other items. John lost it by throwing it in a lake of oil in frustration.
Dad installed Serious Business on the PDA, a program that appears to let him check up with his friends in a manner similar to Twitter. John's dad's screen name is pipefan413. His friends are greyslacks66, wellPressedAttire, officeurchin1280, 2busy4this and fedorafreak.
It is later collected and used by Nannasprite to talk to fedorafreak until his PDA runs out of battery power.
Post-Scratch[]
In the post-scratch session, the PDA (or perhaps an alchemized clone of it) was given to Roxy Lalonde by the Courtyard Droll while she was imprisoned on Derse. It is not clear whether this is the same device that Dad (also in prison) has been using to converse through Serious Business with various Dersites.
Serious Business Goggles[]
The Serious Business Goggles are a hands-free version of the PDA. They are created by John when he combines his glasses and his Dad's PDA. These are very cheap to alchemize, costing only 6 build grist, 3 tar, and 6 mercury. Much like the Clever Disguise, the Goggles are used by equipping them, temporarily removing them from John's Sylladex. They appear to cease John's constant ejection of his PDA. They apparently block his vision when in use, leading him to create a device that is hands-free and doesn't obstruct his vision that can also run Sburb.
How he types replies is unclear. It seems to have been combined with the Cosbytop and possibly the Turntop by the time that John arrives on LOHAC.
Davesprite and Regular Dave make similar items by combining their iPhones with their sunglasses. Rose later creates another similar device by combining her Hubtop with her hairband.
Cosbytop[]
The Cosbytop is a laptop John created by combining a Clean Cosby Poster with his computer. Creating it gives him an alarming sense of satisfaction.
During his dash to get to the first gate, the Cosbytop is expelled from his Sylladex, striking an Imp and falling to the planet below. He later creates a second one so that he can become Jade's server player. When John inexplicably wakes up on his planet, he finds that the Cosbytop is sinking into the oil, along with Nanna's pendant.
John is shown in the future with a new holographic Cosbytop. The new computer looks like a combination of John's Cosbytop, Dave's Turntop, and Jade's Lunchmuffs.
Not to be confused with the similarly-named Crosbytop.