C103414 - STFM 4 x SMT DRAM

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exxos
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C103414 - STFM 4 x SMT DRAM

Post by exxos » Mon Apr 16, 2018 8:08 pm

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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rubber_jonnie
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Re: C103414 - STFM 4 x SMT DRAM

Post by rubber_jonnie » 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?
Collector of old Atari things:
800XL + Ape Warp mod, 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, 2600jr, 7800 and Lynx II
Atari 520ST + Gotek, 1040STF, 4160STE with 32Mhz booster, ROM switcher and CosmosEx
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Smonson
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Re: C103414 - STFM 4 x SMT DRAM

Post by Smonson » Thu Apr 19, 2018 10:14 am

This is the one I've got. Those damn J-leaded chips! :pullhair:

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Re: C103414 - STFM 4 x SMT DRAM

Post by exxos » Thu Apr 19, 2018 10:29 am

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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4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
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Smonson
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Re: C103414 - STFM 4 x SMT DRAM

Post by Smonson » Thu Apr 19, 2018 10:33 am

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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troed
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Re: C103414 - STFM 4 x SMT DRAM

Post by troed » Thu Apr 19, 2018 1:09 pm

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 » 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

Interesting to see that SIMM socket wires up to it though.
Collector of old Atari things:
800XL + Ape Warp mod, 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, 2600jr, 7800 and Lynx II
Atari 520ST + Gotek, 1040STF, 4160STE with 32Mhz booster, ROM switcher and CosmosEx
Plus the rest..
C64 + 1541 and cassette, 2x Sinclair QL, Mac Classic, Mac Performa 6200, Amiga 1200, ICL One Per Desk, Epson HX20, Dreamcast, original Xbox, SNES and a bunch of other bits n bobs I can't remember right now. :D
www.electronicnothingness.co.uk

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Re: C103414 - STFM 4 x SMT DRAM

Post by exxos » Thu Apr 19, 2018 8:17 pm

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:
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

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