WH-27 Problems (was RE: Heathkit H8's, H9's and H-11's)
ajp166 at bellatlantic.net
Thu Apr 19 17:03:49 CDT 2007
>Subject: Re: WH-27 Problems (was RE: Heathkit H8's, H9's and H-11's)
> From: "Barry Watzman" <Watzman at neo.rr.com>
> Date: Thu, 19 Apr 2007 12:54:42 -0400
> To: <cctech at classiccmp.org>
>From: "Robert Armstrong" <bob at jfcl.com>
>Subject: WH-27 Problems (was RE: Heathkit H8's, H9's and H-11's)
> In extended mode the drive could handle 512K diskettes ... So the bottom
>line is that if you want to run standard RT-11 on the H-11, you have to set
>the switch to RX-01 mode and you have the equivalent of an RX01 drive. No
>double density ...
>I don't think that's correct; the controller in the H-27 (WH-27) is a Z-80
>with a Western Digital 1771. The 1771 is most definitely single density
>only. It's not capable of double density.
Barry is correct. I know the beastie well enough and single density was
it's thing. However there was a third party version on the market that
could do DD (but not DEC RX02) and was modeled like the H27.
there wer others in the PDP-11 market that did compatable rx02 DD (two
sided) such as the DSD880 and a few others.
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