Installing an operating system on the 11/83 - update.

[Chuck Guzis]

On 2/22/22 19:43, Jay Jaeger via cctalk wrote:

> Writing a 360KB or RX50 diskette with a 1.2MB drive is a path to a lot
> of frustration.  Not only do you have to double step the drive (software
> often takes care of that part), but the tracks written will be narrower
> than a real RX50 / 306KB drive, providing a smaller signal/noise ratio.
>  And, if you don't start with completely magnetically erased media, any
> left over junk in any data left over may be picked up by the RX50 head.

The RX50 format is a single-sided 96 tpi one, vix:

The format used on a RX50 disk is:

    single sided
    80 tracks
    10 sectors per track
    96 tpi (tracks per inch)
    300 rpm (revolutions per minute)
    250 KHz data rate

>From http://home.iae.nl/users/pb0aia/vax/rx50.html

This is very different from the PC 360K format, which is

     double-sided
     40 tracks
     9 sectors per track
     48 tpi
     300 rpm
     250 Khz data rate.

A "1.2M" disk drive normally spins at 360 RPM, so you have to set the
data rate at 300 Khz.


--Chuck