On 10/13/23 12:07, Martin Bishop via cctalk wrote:
The valve audio afficionados / suppliers also offer both wisdom and components,
e.g.
Ages ago I bought a Potter plug-compatible 9-track tape
drive from a surplus shop. It was designed as a 24xx
compatible drive. I was used to Pertec unformatted drives.
But, apparently, the IBM 2400-series drives had very minimal
logic in them, and fed the analog output from the read amps
directly onto the "bus" cable. Pertec unformatted drives
convert the analog signals through comparators to set FFs
and then produce a trigger pulse that serves as a byte
clock. Making the Potter drive look like a Pertec drive
would be a fair bit of circuitry.
I assume the 727/729 series was similarly primitive, and
would need the same amount of logic to be used.
Jon
