>> -----Original Message-----
>> From: Norman.Dunbar
>> Sent: 11 January 2002 11:29
>> To: ql-users
>> Cc: Norman.Dunbar
>> Subject: RE: [ql-users] Q40/Q60/??? Ultra IO card
>>
>>
>> Silly question from a hardware ignoramus :
>>
>> what is a 6 layer (or 4 layer) board ?
>> I suspect it is to do with the track layour, but all the
>> boards I ever used
>> were 'double sided' = 2 layer ???
Yes.
Nasta will give the definitive reply of course - on one screen please.
Last time I said this to Nasta, he said he was working on an 1800 x
something screen - (8-)#
I did my first 4 layer with Mplane, mainly for an inner 'ground plane'
and a power layer - ie only etch away around vias (layer connections)
and holes. Often the ground plane is there simply to reduce noise, but
it makes it easy to provide the necessary higher current capacity and
avoid voltage drops etc.
However I found I needed to use the +5V layer for some signal lines as
there was simply no room on outer layers.
If a lot of signal layers are internal it nicely hides the pcb design
from hackers (8-)# It makes design debugging (at pcb design stage) far
more difficult. Until we get _real_ 3D monitors, separation is by
colour only - not easy.
A hologram screen would be very nice.
--
QBBS (QL fido BBS 2:257/67) +44(0)1442-828255
mailto:[EMAIL PROTECTED] http://www.firshman.demon.co.uk
Voice: +44(0)1442-828254 Fax: +44(0)1442-828255
TF Services, 29 Longfield Road, TRING, Herts, HP23 4DG
