I bought 5 of this MAX232ACPE from China on eBay for my Max 8085
Project.
3 of 5 was getting very hot and "have burned" somehow.

I took an old TI MAX232N and anything was fine.

-- 
Kind regards / 
Mit freundlichen Grüßen

ExPLIT IT Solutions
Pawel Radomychelski



-----Original Message-----
From: Stephen Adolph <[email protected]>
Reply-To: [email protected]
To: [email protected]
Subject: [M100] Fake MAX3232 RS-232 transceivers from China / Ebay
Date: Wed, 19 May 2021 07:34:21 -0400

As you know I tend to tinker with hardware a lot.
Well I certainly have been schooled on the downside of cheap ebay
parts.

I'm working on a project to make Newdos (aka TS-DOS) more tolerant of
network latency.  After all, we have good solutions now possible for
direct serial over wifi, so what we need is a TS-DOS that can chat over
real IP networks.

To conduct some experiments and observe what is going on, I've made 2
RS-232 inline devices.  

RS-232<----> MAX2323 <---> MAX3232 <---> RS-232
One is simply a repeater; It sits on an RS-232 link  and has 2 back-to
back MAX3232 transceivers such that I can easily see the signals
represented as 3V logic (compatible with my logic analyser).  

RS-232<----> MAX2323 <---|-----|-> MAX3232 <---> RS-232
                         |     |
                          MAX3232
                          |    | 
                           M100
The second device is the same repeater that also includes a connection
on one data line to an in-line M100.  This allows the M100 to be a "man
in the middle" and buffer up/ delay the RS-232 characters in one
direction.  This simulates wide-area network latency.

The "delay" program is attached.

Anyhow, a lot of MAX3232.  Well I bought 10 of what I thought were
actual MAX3232 from ebay.  Example here:
https://www.ebay.ca/itm/273089898048?hash=item3f956d2640:g:PBkAAOSw03lY42ZH

Well, my projects were being frustrated by what I thought were
defective boards.. in fact... read this -->

https://blog.heypete.com/2016/09/11/investigating-fake-max3232-ttl-to-rs-232-chips/

What a hassle.  Long story short - ST3232 is a reasonably priced pin
compatible replacement for MAX3232 that you can get at digikey.
Cost me 25$ to get 10 parts, but ... I would have had several hours
back in my life had I avoided the ebay supply route.

Just goes to show you gotta be careful!

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