Retro Computers

This is my replica Apple-1 with mostly period-correct components. Love this thing

Found a terminal at an art-thing. I wrote a message on it.

[See OP @ Mastodon for followup]

@retrocomputers

Heya! I thought I'd mention that I've been doing a bunch of development on the optical Timex Datalink watches! I have been carefully sniffing data from the original Timex software with a logic analyzer, and have fully reverse engineered every Datalink protocol, the serial Notebook Adapter, and even the CRT syncing graphics! This means that every Datalink device, including every Timex and Motorola watch, all PDAs, and the funny e-BRAIN talking toy is supported!

For those that aren't familiar, the Timex Datalink is a watch that was introduced in 1994 that is essentially a small PDA on your wrist. The early models (supported by this software) have an optical sensor on the top of the face that receives data via visible light.

The original data transfer method involves drawing patterns of lines on a CRT monitor for the watch to receive with the optical sensor. CRTs use electron beams that draw scan lines one-by-one from top to bottom, then it returns to the top and repeats for the next frame. This means that the electron guns turn on when its drawing a white line, and and turn off when its drawing the black background. This produces flashing light as the graphics are drawn, which is ultimately received by the optical sensor and decoded by the Timex Datalink device.

For laptop users, Timex also offered the Datalink Notebook Adapter. Instead of using a CRT monitor, the Notebook Adapter simply flashed a single LED light. This adapter is fully supported by the Timex Datalink software, and sends the same data as a CRT.

However, Notebook Adapters are rare and expensive now, so I reverse-engineered one! Here's my timex_datalink_client Ruby library communicating with my DIY Datalink Notebook Adapter to emit data to a Timex Datalink watch!

And if you want to try the reverse-engineered CRT graphics, I got you covered! I reverse-engineered that, too!

As a fun tidbit, these watches are flight certified by NASA and is one of four watches qualified by NASA for space travel! Here's a shot of James H. Newman wearing a Datalink watch on the Space Shuttle for STS-88!

Here is my Ruby library with all options for all watches reverse-engineered into a tidy model-based syntax!

• https://github.com/synthead/timex_datalink_client

Here is a Notebook Adapter emulator that is fully compatible with all Timex software on old and new machines, and also works with my library too!

• https://github.com/synthead/timex-datalink-arduino

And if you have an anchor that happens to contain an electron beam and wanna try it, here's my library for drawing graphics to a CRT to transfer data!

• https://github.com/synthead/timex_datalink_crt

This has all been done over months of careful effort with lots of VMs, Pentium machines, Windows 98SE, logic analyzers, and solving data puzzles little by little. On July 4th, 2023, I'm proud to announce that I have reverse-engineered every Datalink device with 100% feature compatibility! This is definitely a passion project by all means, and I thought I'd pop in and share this passion with y'all!

Enjoy!

Hi everyone! I just found out about this sub and am happy to be subscribed. Just wondering if you all watch YouTube videos on the subject. I really like Adrian’s Digital Basement and UsagiElectric. I’m very interested in the vacuum tube computers from the latter and trying to figure out how those work!

Does anyone have any recommendations for other channels with a similar sort of educational-ish style? I like being not told exactly wtf is happening with the electronics but the diagnostic and repair and explanation parts are the best!

Anyways thanks for reading!

Attended the SoCal Linux Expo last year and saw this gem. An Apple II GS with a signature from Woz himself

Never owned a Spectrum before. As a teenager I had Commodore 64, like pretty much all my friends. This one boots and works, but as of now I have no way of loading programs. I think I need a DivMMC or something.

I'd like to help increase engagement here. I can tell we have tons of smart people subscribed to help the community with technical issues and the likes. So I'm thinking maybe we should have a game or computer of the month. Talk about what you have, what you're playing or maybe programming on.

What is everyone's thoughts?

Cheers Henry

I want to buy a micro, which one is good to get started with that's not very expensive? I live in Canada. Looking for one I can use BASIC with

Hey everyone,

I hope everyone is doing well and keeping safe.

I'm hoping I can rally some help with this Retro Computers Lemmy. Maybe 2 more mods to help?

Message me or leave a reply!

Cheers Henry

a amazing game for the VIC-20. and avalable on tape ! i think its maybe one of the best game i played on the machine.

Hey,

So I want to use my Plus/4 but I don't want to kill it. I've read/heard that the Plus/4 will eventually off itself, the TED will die(?) So I'm scared to use the damn thing.

I got a bunch of tapes I want to play, but I don't want to damage the thing. What's the approach to ensure I don't cook the TED from just using it?

PS: Not power supply related. I have a Ray Carlsen multi PSU.