Deleted by the author from thread number 4177179

TechEkspert wrote:

During a conversation today, I was inspired to mention the tape storage devices used by the Odra computers. I completely omitted this from the text of the article, so it’s time to rectify that. Admittedly, this is the topic I know least about, but I haven’t seen a description of tape storage systems appear on elektroda.pl yet. On Wikipedia, you can find a description of a Polish tape storage system PT-3 . There is a photo of the PT-3 there; at the top you can see two distinctive tape reels and two vertical rectangular columns below.

Source: Wikipedia, Polish PT-3 tape storage system, by Merlin CC3.0

Upon examining the details of the Wikipedia entry, it turns out that the tape used a 9-track system for both writing and reading. This appears to be a similar approach to that used in punched tape, in this case with 8 bits of data and one bit for parity checking. Inside were pumps creating a vacuum... Thanks to this, the rectangular columns acted as a buffer for the tape, and rapid acceleration or deceleration of the tape did not cause the medium to break. The 750 metres of tape on the reel provided significant inertia at a feed speed of 3 m/s or a rewinding speed of 6 m/s. Recording on the tape was carried out using NRZI, which facilitated signal transmission through the signal path. The tapes had start and end markers, with 15.2 mm gaps between blocks. All this was necessary to send a data stream of 24,000 bytes/s or 96,000 bytes/s to the Odra. PT-3 power supply: 220/380 V, 50 Hz, power consumption 1.6 kW.

Let’s take a look at the print heads in the older PT-2 model:

Source: Wikipedia, heads of the Polish PT-2 tape storage system, by Topory CC4.0

The sight of the heads with their shielded cables is impressive; the design has a Nagra-style feel to it
Each head is labelled O (read), Z (write) or K (erase).

I haven’t found any footage showing the PT-3 in operation, but I suspect that the designers drew heavily on IBM products or, as in the case of the wheel, it was invented independently in many places and at different times.

More details on the design of such tape storage devices can be found in this video: https://www.youtube.com/watch?v=7Lh4CMz_Z6M

Those were strange times

As for core/ferrite memory:

I can see there were threads on this topic on elektroda.pl
Bead memory gallery
The development and miniaturisation of electronics