Date   : Sun, 28 Sep 2003 09:48:11 +0100
From   : Andrew Hancock <Andrew.Hancock@...>
Subject: Re: BBC Micro lazy delayed boot!

 
1. This is something I need to confirm, but didn't want to remove the pcb
unless it was necessary. Food for thought.

2. If DFS is unplugged, Beeb startup/boot is normal. I assume with the DNFS
1.2 installed some handshaking occurs to check for presence of the 8271
chip, because if NO 8271 chip, DFS is not loaded/mapped into memory.

3. Link S9 is cut. (no link present)

4. Yes, a complete 8271 disc interface kit has been fitted including ic86
(74LS393) and ic87 (74LS123).

Something I forgot to mention, that when the Beeb is waiting after power-on
the Caps and Shift Lock lights are both lit.

And I've just discovered this morning, the colder the machine the longer the
wait, because yesterday evening as the Beeb was left on the warmer it got
the quicker it booted.

Power-on this morning, it takes 15 second delay before booting.

Regards

Andrew




-----Original Message-----
From: Mike Tomlinson [mailto:mike@...] 
Sent: 28 September 2003 02:23
To: bbc-micro@...
Subject: Re: [BBC-Micro] BBC Micro lazy delayed boot!

In article <6A4F555CEA3CD5118DBD0002E30AC0912C0826@...
consultants.co.uk>, Andrew Hancock <Andrew.Hancock@...
consultants.co.uk> writes

>When the 8271 chip is inserted, if I power-on the Beeb, I get the first
>tone, flashing cursor and 4 seconds later the second tone and the Beeb
>boots, and displays usual BBC Computer 32K, Acorn DFS, Basic.

Strange.  Thoughts:

1.  How sure are you that the 8271 socket is OK (I'm thinking that the
pins on the 1770 upgrade riser may have loosened the socket a bit too
much.)

2.  Tried it with the DFS ROM unplugged?  What happens?

3.  Is link S9 (to the top and left of the 8271) cut?

4.  When you reverted from the 1770 disc kit to the 8271, did you refit
the two chips which are replaced with wire links in the 1770 kit?  One
is is86 (74LS393) and the other is ic87 (74LS123).

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