HP Integral PC Manuals
dr.emiel at xs4all.nl
Mon May 5 15:58:18 CDT 2008
Yes V1.0.0 I think the same it's just designed to keep the motors running.
Maybe to get the media running before the heads touch it, to prevent
start/stop spots ?
Well the ability to make errors is what makes us human ;-)
The hartbeat should it be some kind of watchdog signal or a sync for
realtime processing ?
----- Original Message -----
From: "Tony Duell" <ard at p850ug1.demon.co.uk>
To: <cctalk at classiccmp.org>
Sent: Monday, May 05, 2008 7:58 PM
Subject: Re: HP Integral PC Manuals
>> Checked today, and the floppymotor keeps on running...
> And you have V1.0 ROMs, yes?
> I think we can assume there's not a hardware fualt on all 3 machines (my
> 2 and yours), and that the floppy was designed to keep running. I wonder
> why? The MotorOn line is certainly software-controlled, it's not simply
> tied low or anything.
>> Pictures are made and on it's way to you.
> Thanks, I've seen them. The ROM module is very different to my V5.0 one.
> 2 ohter errors I've spotted in 'my' Integral schematics :-(.
> 1) Input 0 of the Interrupt priority encoder should be tied to ground,
> not +5V. In fact this would make no differece to the operation of the
> machine (the only ontput to change state isn't used!).
> 2) The commonned pins on the floppy drive connector on the logic B PCB
> are not suprisingig also grounded. I must have just missed off the ground
> symol :-)
> Anyother thing that might be of interest is that there's a 10Hz
> 'heartbeat' on the IR1 interrupt line, it comes from the real time clock
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