Subject: Re: No way to install NetBSD on uVaxII
To: None <>
From: John Wilson <>
List: port-vax
Date: 08/16/1998 20:06:45
>From: Kees Stravers <>

>You may 
>want to first try some experimenting with the PUTR program. I'm not
>sure, but if I understand the documentation right, it is possible to
>use it to read and write with a genuine RX50 drive connected to a
>PC floppy disc controller.

As the code stands now it shouldn't work (since the RX50 emulation uses
1.2 MB 360 RPM drives at 300 kHz rather than genuine 300 RPM drives at
250 kHz).  Nick Zymaris has experimented with this so he would know more;
I think the main problem (besides the data rate which could be fixed by
changing one table entry) is that RX50s use a semi-normal cable pinout
rather than the weird PC deal with the separate motor enables for each
drive (I think that's the main difference, there may be others).  So I
think at a minimum it would require switching a few wires around on the
cable, if I remember right it's not solvable in software because of the
fact that the drive enables aren't split out one bit per drive like the
motor enables are (in the PC FDC registers).

>A 720k 3.5i drive is a 300 rpm 80 tracks double sided drive. The PC
>version reacts to drive select 1. 
>Connect one to a PC and tell PUTR it is a RX50. Copy the RX50 install
>binaries to 720K floppies and connect the drive to the microvax using
>an untwisted cable. Try to boot from DUA2, the second floppy drive.
>This might work. I think it will, but unfortunately I still haven't had
>the time to test this.

Sounds like a good plan...

John Wilson
D Bit