First post, by mattw
Let me begin with explaining what I mean by "elaborate hoax" - I see those cards are circulating in the last 1-2 years or so and are sold as "1991 NOS" (i.e. New Old Stock from 1991), I first encounter such card in the blog here:
https://gameroomramblings.com/2021/11/30/midi … with-a-mdr-401/
while searching about some MPU-401 information due to my interest in this:
Anyway, I digress and so why "elaborate hoax" - while someone tried really very hard to make them look like NOS from 1991, i.e. all the basic logic chips are with date codes from 1991, many things raised my suspicions looking at more and more pictures of those cards, even to the extend questioning if such card has even existed in reality in the past or someone invented in the recent years.
So, I am attaching couple pictures of those cards - you most likely will need to use GIMP and brightness/contrast controls to see what I am going to list:
1. on this picture I see:
1.1. crystal from 1999 - strange, but I guess not enough
1.2. Zilog chip with that solid "Z" logo (Zilog never had such logo) sold from Chinese seller with date codes from recent years like 2010, 2019:
I don't even know - what are those Zilogs? I mean some Chinese clones or what exactly? that alone is interesting enough to me, if someone knows, to share the information about Zilogs with such logo and very recent datecodes of manufacturing.
1.3. Botch wires (like prototype of someone cloning old card or developing new one) plus even more suspicious and revealing those silk-screen "ID Codes" (I don't know how to call them - feel free to educate me in case they have some special name) that low-cost Chinese PCB manufactures put and put sloppy, i.e. automatically by the PCB manufacture, literally slapped on top of the "330H" label
2. on this picture:
2.1. more or less the same observations with the difference - no botch wires, the PCB manufacturer silk-screen ID/Code is moved to not overlap the "330H" label, i.e. looks like even more recent "production"
2.2. the OptoCoupler is "6N138" - and that I cannot find in existence before 2004 (Vishay datasheet) and on another picture that I cannot find at the moment, I even see "OnSemi" 6N138 OptoCoupler, which are like 2010 and newer (as far as I can tell)
So, all of the above, makes me think someone very unethically is abusing and exploiting the retro-gaming community. I have no problem, with selling newly made boards of old hardware, i.e. clones, but selling them as "NOS 1991" and putting effort to make them look like that with using old logic chips with 1991 datecodes - is really a new low to me!
In fact at this point I don't see even a single evidence such "MDR-401" card really existed in the past - it starts to look more and more to me like someone invented it very recently when those "NOS 1991" cards started to circulate, when they in realty are some new development.
I will appreciate to hear your thoughts on this!
