Need cable w/RS232 connector to ALDL connector for my '94.
 

So i get my Tuner CATS software w/cable for my '94 but it has a USB interface - which is something i tried to avoid. Ive read bad of the USB interfaces so i bought a older laptop w/RS232 port to avoid any serial comm issues. Tuner CATs say what i got is what i get.:icon_present: Well im still thinking the older laptop speed is better matchup to my PCM and the fact i bought 2 same model laptops for this i dont want to go the USB route.

Anyone selling a good RS232 to ALDL cable?

You may have to make one. There are only a few parts (2 transistors [2n3904 or similar], 1 diode, and 3 resistors) not including the connectors.

Makes me wonder if it could be as easy as DB25 to DB9 connector conversion. The USB to serial converter is on a DB25 connector. But i dont see any circuit/box on upstream of the DB25 on my CATS cable. What is the pinout for the DB25 connector? OK i see it below the DB9 pin out. Im thinkn i still need a "interface circuit" regardless of connectors.

Really dont want to build a circuit now.

Use a multimeter to check continuity from pin M on the 12 pin connector. If it goes straight through to a pin on the DB25, then there isn't any interface circuit inside. If it doesn't, there may be one in one of the connector bodies.

This converter/interface for even the RS232 cable is a game changer. It destroyes the thought of reduced signal conversion. Now im thinking just going with modern touch screen laptop w/large batt life and big 15" screen. I see nice laptops under 300 bucks. I only get to load this version of Tuner CATS once so i want a dedicated computer that will be current hardware and software wise for quite a while.

Hoping pricing gets better by Black Friday. Any precautions or suggestions? USB driven now? Forget the RS232?

I don't know what you mean by reduced signal conversion. The output circuit is open collector. It will drive any voltage from 1 to about 100 volts (the limit of the transistor). The input is similar, any input from maybe 3 volts and up. RS232 doesn't require a 12v signal operation, it's just typical. The R2 component in the schematic is optional. Personally I would prefer the faster speed of the newer pc's and operating systems. Does Tuner Cats work for Win 7, 8, or 10?

Good question on the OS. The instructions only address WIN 7 and WIN 8 but that doesnt means it wont run on WIN 10 or that the instructions havent been updated. I need to contact Tuner CATS again.

What i mean by reducing signal conversion(s) is that anytime u add an interface - even connector contacts let alone signal modifier/converter/repeater - u add the possibility of a data bit error or signal loss. And that RS232 interface doesnt call out any part numbers which leaves open the question of component specifications. Response time? Thermal effects? I prefer something vendor developed and proven. I dont want to troubleshoot my equipment while im trying to troubleshoot my tune.

BTW i havent used WIN 8 at all but heard a lot of disappointments with it though it supposed to be touch screen operable. Im guessing WIN 10 is a better product and touch screen friendly. Any suggestion or experience with either?

If you buy something with Win 8, you can immediately upgrade to 8.1 for free. Once you have 8.1, you can upgrade to Win 10 for free for up to about a year from now. I highly recommend doing that. Win 8 or 8.1 is a mess in my opinion. Win 10 has the same capability but drops back to the friendlier Win 7 user interface.

The reason you don't see any specs or part numbers is because virtually all transistors have a bandwidth in the many, many megaHertz range. Minimum of about 20 Mhz. Way faster than the 8.192 kiloHertz rate required for the PCM. For example, the 2N3904 (very common) has a minimum of 300 MHz.