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Re: DMA HEADER REV H1
Posted: Wed Dec 19, 2018 11:16 am
by ijor
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.
Re: DMA HEADER REV H1
Posted: Wed Dec 19, 2018 11:23 am
by kodak80
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?
Re: DMA HEADER REV H1
Posted: Wed Dec 19, 2018 11:35 am
by exxos
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.
Re: DMA HEADER REV H1
Posted: Wed Dec 19, 2018 11:44 am
by Icky
Just took a look and Gigafile header board is for MegaSTE. See mine below in situ.
- IMG_2436.png (1.2 MiB) Viewed 4841 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 4841 times
Re: DMA HEADER REV H1
Posted: Wed Dec 19, 2018 11:56 am
by ijor
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.
Re: DMA HEADER REV H1
Posted: Wed Dec 19, 2018 2:17 pm
by PaulJ
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!
Re: DMA HEADER REV H1
Posted: Wed Dec 19, 2018 2:25 pm
by PaulJ
Re: DMA HEADER REV H1
Posted: Wed Dec 19, 2018 2:29 pm
by exxos
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
Re: DMA HEADER REV H1
Posted: Wed Dec 19, 2018 2:35 pm
by PaulJ
exxos wrote: ↑Wed Dec 19, 2018 2:29 pm
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.
Re: DMA HEADER REV H1
Posted: Wed Dec 19, 2018 3:26 pm
by exxos
Schematic is there
so I can just add the header