Whaou! Core memory, Dekatrons, and now 9-track digital tape!

That's quite unique for a "homebrew computer".

I think the only peripheral missing would be a teleprinter! 

I'm very impatient to see some progress on this project.

Do you plan to use several tape drives in parallel, at the same time?

What about tape drive interface? Is the tape drive easy to interface? I know that some tape drive need specific driver... But in a less than 10kB computer, it could be difficult to integrate.

I have two tape drivers because of separate memory architecture. So one tape recorder would be used for instructions and another one - for data.

Tape driver interface is very simple because of nine tracks - It have fully parallel schematic  - so ou just have 9 bits on the output regardless playing direction - forward or backward.

Recording density is 800 bits per inch. And bandwidth 10 Kbytes/s

@Artem Kashkanov 

OK, thanks. I don't fully understand the link between "harvard architecture" (separated program and data memories) and the presence of 2 tape drives. Do you plan to have 2 separated logics that can load/store each tape to each memory bank? Will this logic be 100% wired (with vacuum tubes? Transistors?), or partly "software based" (codded in brainfuck)?

I update project  details and explained Tape recordes usage.

Thank you, that's perfect. I undestand your choice now!