Logic Analyser on the Cheap

Tool suggestions, soldering tips, general useful electronics knowhow.
troed
Moderator
Moderator
Posts: 908
Joined: Mon Aug 21, 2017 10:27 pm

Re: Logic Analyser on the Cheap

Post by troed »

It's a little more than 10GBP, but I'm very happy with my DSLogic USB LA.
User avatar
rpineau
Posts: 534
Joined: Thu Aug 17, 2017 6:08 pm
Location: USA
Contact:

Re: Logic Analyser on the Cheap

Post by rpineau »

I used both a Logic 8 and a Logic Pro 16 from Saleae. I did test a bunch of cheap ones (up to 32 channel like exxos, we had the same one) just to see them fail miserably and not work as expected. I think buying the Saleae Logic Pro 16 was the best thing I did to help me debug the 68020 board.
If you're only doing tests on Arduino and slow micro-controllers, the cheap LA might be ok (assuming they have proper input protection), but after that, if you need to do some serious (amateur serious .. not Pro 16 layer board debugging serious), you'll run into issues (harware quality, software, ....).
Just my 2 cents.
Rodolphe
Working ones : MegaSTE (68020) / TT030 / Falcon with AB040 & Eclipse / 1040STF
Need testing : Falcon with CT2
User avatar
rubber_jonnie
Site Admin
Site Admin
Posts: 10465
Joined: Thu Aug 17, 2017 7:40 pm
Location: Essex
Contact:

Re: Logic Analyser on the Cheap

Post by rubber_jonnie »

Out of interest, part way down this page is a logic analyser for the ST http://www.gossuin.be/index.php/shop.
I have now also acquired one of the cheap ones and hope to get to test it soon.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
User avatar
PhilC
Moderator
Moderator
Posts: 6012
Joined: Fri Mar 23, 2018 8:22 pm

Re: Logic Analyser on the Cheap

Post by PhilC »

Appart from diagnosing new boards etc, would you say that an LA is of much use for fixing retro computers?
If it ain't broke, test it to Destruction.
ijor
Posts: 428
Joined: Fri Nov 30, 2018 8:45 pm

Re: Logic Analyser on the Cheap

Post by ijor »

Logic Pro are great products, but IMHO they are quite overpriced unless you need two specific features. All the inputs are both digital and analog, and it works with USB 3.0 streaming. The latter means you can capture an enormous amount of data. If you don't need those features, there are much more affordable options, yet with similar quality and specs.
http://github.com/ijor/fx68k 68000 cycle exact FPGA core
FX CAST Cycle Accurate Atari ST core
http://pasti.fxatari.com
terriblefire
Moderator Team
Moderator Team
Posts: 5368
Joined: Mon Aug 28, 2017 10:56 pm
Location: Glasgow, UK

Re: Logic Analyser on the Cheap

Post by terriblefire »

I use an HP1661CS. There is nothing as good for the money.

Just my 2 pence...

It’s not budget but if you are going past 2-3Mhz the DuPont wire probes are no use. They’re effectively 1:1 probes with all the documented issues you get with those.

The Old HPs can be picked up for 100-300 GBP. Each wire is a 1:100 probe... Well worth it. Plus they’re indestructible and have service manuals etc.
———
"It is not necessarily a supply voltage at no load, but the amount of current it can provide when touched that
indicates how much hurting you shall receive."
tzok
Posts: 337
Joined: Sat Dec 30, 2017 2:27 pm

Re: Logic Analyser on the Cheap

Post by tzok »

Recently I was trying to diagnose my... diagnostic cart with a Logic Analyzer (Logic-8 clone). I did it, but not in the way I'd like to. All lines were looking legit on the LA software, but I realized that, with probes connected, cart behaves differently. So I started disconnecting the probes, one by one and observing if this affects behavior of the cart. In this way I've found one pin which was causing troubles, which led me to finding a "cold" solder joint. After all I much prefer DSO over LA for diagnostics.
User avatar
kludge
Posts: 393
Joined: Thu Nov 08, 2018 2:05 pm
Location: Sweden

Re: Logic Analyser on the Cheap

Post by kludge »

It all depends on what you'll be using the LA for. I have one of the cheap Chinese clones and it was a huge help trying to determine how to interface an Arduino to an old Texas Instruments TI-74 BASICALC. I only had to keep track of about 6 signals and the bitrate is quite low, so the device was definitely enough for that. I haven't hooked it up to anything faster, though :)
A kludge is a workaround or quick-and-dirty solution that is clumsy, inelegant, inefficient, difficult to extend and hard to maintain.

My lack of focus:
[ 4 * Amiga 500 ][ Amiga 500+ ][ 2 * Amiga 600 ][ A1200 ][ Amiga 2000 w/ A2386 ][ Amiga 4000/030 w/ CyberVision 64 3D, FastLane SCSI Z3 ][ CD32 ][ VIC-20 ][ 4 * C64 Breadbin ][ 5 * C64C ][ 2 * C128 ][ C128D ][ C64 DTV ][ Mac Classic ][ Mac Classic II ][ Mac Colour Classic ]
User avatar
PaulJ
Posts: 1568
Joined: Sun Apr 08, 2018 1:14 am
Location: USA

Re: Logic Analyser on the Cheap

Post by PaulJ »

I have an 16 channel Chinese LA also and in some cases its quite effective but if its a higher freq signal and loading is a factor its usually ineffective or useless. Never the less it is helpful but I plan on upgrading to a HP analyzer at some point... most like when the Chinese LA lets me down.
terriblefire
Moderator Team
Moderator Team
Posts: 5368
Joined: Mon Aug 28, 2017 10:56 pm
Location: Glasgow, UK

Re: Logic Analyser on the Cheap

Post by terriblefire »

I recently (3 weeks ago) picked up a second HP1661CS Scope for $50 + shipping (which was $70). I cant recommend them enough
———
"It is not necessarily a supply voltage at no load, but the amount of current it can provide when touched that
indicates how much hurting you shall receive."
Post Reply

Return to “ELECTRONICS”