Archived from groups: rec.games.video.arcade.collecting (
More info?)
agreed... I was just trying to tell him to watch out as a number of the
scopes up on e-bay don't have probes with them... they seem to go at the
same price regardless, so unless you want to shell out another $20-$30 bucks
for probes it pays to just watch closely and ask the seller what's included.
It's just one of those "assume" issues that can lead to disappointment
(heck.. for a $100 scope, having to go and spend another $20 on probes is
quite a penalty).
steve
"Mark C. Spaeth" <mspaeth@plancherel.mit.edu> wrote in message
news:430de622$0$574$b45e6eb0@senator-bedfellow.mit.edu...
> Steve Muccione <home*DOT*muccione@verizon.net> wrote:
> : I've been doing scope research recently with the intention of buying one
> : (was all set to until I just bought a logic analyzer instead).
> :
> : It seems the best bang for your buck in terms of digital scopes are the
> : HP54201A's. They are really 50Mhz dual input scopes, but they seem to
> go
> : for around $100 on e-bay.
> :
> :
>
http://cgi.ebay.com/HP-54201A-300MHz-Digitizing-Oscilloscope-2-HP-Probes_W0QQitemZ7540712607QQcategoryZ104247QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
> :
> : for example... but if you look under completed items you'll see a number
> of
> : them all went for around the $100 mark.
> :
> : Tek seems to be more expensive, but they have knobs... nothing quite
> like
> : knobs on a scope (as HP discovered and later put them back on their
> scopes
> : after a foray of knobless scopes).
> :
> : you can get 4 input scopes but they'll be more... (often quite a bit
> unless
> : you get lucky).
> :
> : Make sure that it comes with the probes... they can be expensive to buy
> : otherwise.
>
>
> For the signal speeds on game boards, you really don't need fancy probes.
> The only 'fast' signals are the initial clock before it gets divided down,
> the low order horizonal signals, and the video outs. Game boards are
> essentially all digital, so the 'shape' of the signals doesn't matter
> much,
> Something like the 6Mhz bit clock on pacman won't look nice and square
> with
> a cheap probe, but it'll be fast enough to pass the first couple of
> harmonics and get a reasonable picture of the signal.:
> :
> --
> Mark Spaeth mspaeth@mtl.mit.edu
> 50 Vassar St., #38.265 mspaeth@mit.edu
> Cambridge, MA 02139
> (617) 452-2354
http://rgvac.978.org/~mspaeth
>