At 14:34 21/10/2004 +0000, you wrote:
>On Thu, 2004-10-21 at 07:39 -0400, Dave Dunfield wrote:
>> Anything you would add?
>
>The comment made recently about memory drawing excess current if inputs
>are left floating is interesting though. Proof that you do need to know
>about the system you're testing as taking the modular approach to
>powering up doesn't always work and might actually do more harm than
>good.
Thats true, and there are other concerns - I've seen devices which go thermo
if there's no clock! - Thats why I do this only if I can't test the power
supply separately, and only power it very briefly - long enough to verify
the power rails.
>The other thing I'd add to that is to always use a dummy form of mass
>storage in place of any real media, even after you're confident that the
>power supply is OK - just in case on first full boot the system decides
>to stomp all over the media.
Good point - I always disconnect drives etc. at first power-up, but one
area where I've seen people have trouble is in floppy disks - DON'T USE
THE MASTER DISKETTE ON FIRST ATTEMPT TO BOOT! I always try to find ways
to backup the disks and boot from a copy if at all possible.
I just got a Kaypro in where the guy had tried to boot it after it had
sat for a number of years, got a loud shrieking noise after which the boot
disk was missing a band of oxide - Fortunately, he had the sense not to
try another disk.
Regards,
Dave--
dave04a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Vintage computing equipment collector.
http://www.parse.com/~ddunfield/museum/index.html
Received on Thu Oct 21 2004 - 11:22:56 BST