DMA HEADER REV H1

ijor · Post by **ijor** » Wed Dec 19, 2018 11:16 am

kodak80 wrote: ↑Wed Dec 19, 2018 11:09 am Whilst I do not have an UltraSatan(US) (a friend has one), the schematics show that it also has a 20 pin IDC connector and a micro USB for power. From what I have and the schematic on the US, all have the same 20 pin IDC connector.

Not sure if that was an answer to my post or not. But yes, all have the same connector. What I meant is that it is different than the connector on the MEGA motherboard (has to be, obviously, 20 vs 24 pins), which is what Exxos used at the top of this thread.

kodak80 · Post by **kodak80** » Wed Dec 19, 2018 11:23 am

ijor wrote: ↑Wed Dec 19, 2018 11:16 am
kodak80 wrote: ↑Wed Dec 19, 2018 11:09 am Whilst I do not have an UltraSatan(US) (a friend has one), the schematics show that it also has a 20 pin IDC connector and a micro USB for power. From what I have and the schematic on the US, all have the same 20 pin IDC connector.
Not sure if that was an answer to my post or not. But yes, all have the same connector. What I meant is that it is different than the connector on the MEGA motherboard (has to be, obviously, 20 vs 24 pins), which is what Exxos used at the top of this thread.

I wonder what the internal connector on the Mega was designed for when the external DMA only has 19 pins?

Post by **exxos** » Wed Dec 19, 2018 11:35 am

A lot of pins are connected to gnd. So 19 or 20 pin connectors make sense really.

I will likely have to add both headers to cover everything. But will likely gear it up more for ultrasatan as its obtainable.

Post by **Icky** » Wed Dec 19, 2018 11:44 am

Just took a look and Gigafile header board is for MegaSTE. See mine below in situ.

: IMG_2436.png (1.2 MiB) Viewed 4840 times

The header on the MegaSTE is 30 pins around the DMA. Last six pins tied to Vcc or GND.

: Screenshot 2018-12-19 at 11.42.06.png (214.94 KiB) Viewed 4840 times

ijor · Post by **ijor** » Wed Dec 19, 2018 11:56 am

kodak80 wrote: ↑Wed Dec 19, 2018 11:23 am I wonder what the internal connector on the Mega was designed for when the external DMA only has 19 pins?

Probably the same reason that the floppy cable has 34 wires but only use half of them. To reduce crosstalk between the signals. If you check the pinout you would see that the extra gnd wires are inserted between adjacent data signals.

PaulJ · Post by **PaulJ** » Wed Dec 19, 2018 2:17 pm

I was thinking of taking the internal scsi board out of my MSTE and putting it in my mega 4. Both have the same number of pins but there were some differences. I didn't really check into the differences but I'm assumming it would work. We all now what happens when I assume. Always get burned!

PaulJ · Post by **PaulJ** » Wed Dec 19, 2018 2:25 pm

Exxos, excuse the thread jack but thanks for putting together the Eagle tutorial. As much as I hate windoze I have a few windows machines in the closet and storage shed. (good place for them) I believe I have a windoze 7 machine I can pull out and give your tutorial a try. Eagle may be easier since I have an expert to ask questions of. But once again thanks!! Still going to pursue Kicad though because it runs on my mac pro.

Post by **exxos** » Wed Dec 19, 2018 2:29 pm

PaulJ wrote: ↑Wed Dec 19, 2018 2:25 pm Exxos, excuse the thread jack but thanks for putting together the Eagle tutorial. As much as I hate windoze I have a few windows machines in the closet and storage shed. (good place for them) I believe I have a windoze 7 machine I can pull out and give your tutorial a try. Eagle may be easier since I have an expert to ask questions of. But once again thanks!! Still going to pursue Kicad though because it runs on my mac pro.

I will unlock the thread once the guide is finished

I'm about half way through the schematic part.. Then part 2 will be the PCB side of things. A few people want a guide to get started

PaulJ · Post by **PaulJ** » Wed Dec 19, 2018 2:35 pm

exxos wrote: ↑Wed Dec 19, 2018 2:29 pm
PaulJ wrote: ↑Wed Dec 19, 2018 2:25 pm Exxos, excuse the thread jack but thanks for putting together the Eagle tutorial. As much as I hate windoze I have a few windows machines in the closet and storage shed. (good place for them) I believe I have a windoze 7 machine I can pull out and give your tutorial a try. Eagle may be easier since I have an expert to ask questions of. But once again thanks!! Still going to pursue Kicad though because it runs on my mac pro.

I will unlock the thread once the guide is finished I'm about half way through the schematic part.. Then part 2 will be the PCB side of things. A few people want a guide to get started

It will be great to be able to throw together a board. Thirty years ago I was making double sided pc boards via photo sensitied boards but without via's they were marginal at best.

Post by **exxos** » Wed Dec 19, 2018 3:26 pm

ijor wrote: ↑Wed Dec 19, 2018 11:09 am It is not the same pinout as the internal MEGA connector. Lotharek sells an adapter: https://lotharek.pl/productdetail.php?id=50

Schematic is there

so I can just add the header

DMA HEADER REV H1

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