[cctalk] Re: IBM 727 tape drive

On 10/13/23 12:07, Martin Bishop via cctalk wrote: 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