In the innocent days of the early 90s the future of personal computing still seemed to be wide open, with pundits making various statements regarding tis potential trajectories. To many, the internet and especially the World Wide Web didn’t seem to be of any major significance, as it didn’t have the reach or bandwidth for the Hot New Thing^tm in the world of PCs: multimedia. Enter the CD-ROM, which since its introduction in 1985 had brought the tantalizing feature of seemingly near-infinite storage within reach, and became cheap enough for many in the early 90s. In a recent article by [Harry McCracken] he reflects on this era, and how before long it became clear that it was merely a bubble.

Of course, there was a lot of good in CD-ROMs, especially when considering having access to something like Encarta before Wikipedia and broadband internet was a thing. It also enabled software titles to be distributed without the restrictions of floppy disks. We fondly remember installing Windows 95 (without Internet Explorer) off 13 1.44 MB floppies, followed by a few buckets of Microsoft Office floppies. All pray to the computer gods for no sudden unreadable floppy.

Inevitably, there was a lot of shovelware on CD-ROMs, and after the usefulness of getting free AOL floppies (which you could rewrite), the read-only CD-ROMs you got in every magazine and spam mailing were a big disappointment. Although CD-ROMs and DVDs still serve a purpose today, it’s clear that along with the collapse of the Internet Bubble of the late 90s, early 2000s, optical media has found a much happier place. It’s still hard to beat the sheer value of using CD-R(W)s and DVD-/+R(W)s (and BD-Rs) for offline backups, even if for games and multimedia they do not appear to be relevant any more.

If you’re interested in another depiction of this period, it’s somewhere we’ve been before.

[Luizão] wanted to create some hardware to honour the memory of the technology used to put man on the moon and chose the literal core of the project, that of the hardware used to store the software that provided the guidance. We’re talking about the magnetic core rope memory used in the Colossus and Luminary guidance computers. [Luizão] didn’t go totally all out and make a direct copy but instead produced a scaled-down but supersized demo board with just eight cores, each with twelve addressable lines, producing a memory with 96 bits.

The components chosen are all big honking through-hole parts, reminiscent of those available at the time, nicely laid out in an educational context. You could easily show someone how to re-code the memory with only a screwdriver to hand; no microscope is required for this memory. The board was designed in EasyEDA, and is about as simple as possible. Being an AC system, this operates in a continuous wave fashion rather than a pulsed operation mode, as a practical memory would. A clock input drives a large buffer transistor, which pushes current through one of the address wires via a 12-way rotary switch. The cores then act as transformers. If the address wire passes through the core, the signal is passed to the secondary coil, which feeds a simple rectifying amplifier and lights the corresponding LED. Eight such circuits operate in parallel, one per bit. Extending this would be easy.

Obviously, we’ve covered the Apollo program a fair bit. Here’s a fun tale about recovering the guidance software from the real hardware. Like always, the various space programs create new technologies that we mere mortals get to use, such as an auto-dialling telephone.

(video in Brazilian Portuguese)