C103414 REV 1.1 - STFM 4 x SMT DRAM

STFM motherboards.
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exxos
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C103414 REV 1.1 - STFM 4 x SMT DRAM

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ST_Motherboard_C103414-001_Rev_1_1_exxos.jpg
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If anyone has a better image please add it!
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Re: C103414 - STFM 4 x SMT DRAM

Post by rubber_jonnie »

What is that empty section to the right of the empty bank, with the large cap to the top right?
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Re: C103414 - STFM 4 x SMT DRAM

Post by Smonson »

This is the one I've got. Those damn J-leaded chips! :pullhair:
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Re: C103414 - STFM 4 x SMT DRAM

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rubber_jonnie wrote: Mon Apr 16, 2018 10:53 pm What is that empty section to the right of the empty bank, with the large cap to the top right?
No idea... Looks like a bunch of pointless jumper tracks which basically jump over section of other track doesn't go to anything :shrug: looks like we got a bit of a mystery.. Maybe it was just left over from converting the PCB layout from the larger the RAM bank versions and the designer was probably doing this on the Friday afternoon and never finish removing the old layout :shrug:

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Re: C103414 - STFM 4 x SMT DRAM

Post by Smonson »

I don't know what those pads are for either, but I can tell you that the left side is connected directly to the data bus. That's where I installed my SIMM socket.

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Re: C103414 - STFM 4 x SMT DRAM

Post by troed »

Looks like the designer assumed data bus would have resistors like the address bus. Same spacing, right?
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Re: C103414 - STFM 4 x SMT DRAM

Post by rubber_jonnie »

I like the idea that it's a Friday afternoon workaround because they got higher capacity RAM chips :D

Interesting to see that SIMM socket wires up to it though.
Collector of many retro things!
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Re: C103414 - STFM 4 x SMT DRAM

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rubber_jonnie wrote: Thu Apr 19, 2018 5:43 pm I like the idea that it's a Friday afternoon workaround because they got higher capacity RAM chips :D
it would seen originally they were pads the resistors later were bridged over the tracks on the PCB, and the original holes just not removed..

I would assume this board came out after the 32 chip RAM version.. And they did not have the resistors on that board.. So I don't really know why they would decide suddenly add resistors, then apparently decide they were not needed and bridge them over with tracks on the PCB... :shrug: maybe just was precaution when they were starting to use the new RAM chips :shrug:
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Re: C103414 - STFM 4 x SMT DRAM

Post by sandord »

Here's my version, which is sharp enough to read all chip writings etc.
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