Reply 20 of 37, by snufkin
Dunno if this'll be useful, but looking at what can be seen of the PCB traces, it looks like it's possible to make a few guesses. The 44 pin connector looks to have Ground and Power (based on the trace going via the capacitors) that line up with the 44 pin ATA pinout. There are also about 7 connections between the connectors that we can see all of (pins 5, 10, 11, 30, 34, 35, 36 on the 50 pin connector), and we can also see the power and ground connections on the 50 pin.
Putting that together, it looks like the 50 pin connector might have the same layout as the 44 pin connector, but with a couple of extra rows of ground or signal pins.
I wrote out a table, basing the 44pin connector on https://old.pinouts.ru/HD/Ata44Internal_pinout.shtml, and filling in what can be seen of the 50 pin (at first I marked the thicker traces as power, but now think I'm wrong about that):
44pin 50 pin
GND 1 26
/RST 1 2 GND 2 27 GND
DD7 3 4 DD8 3 28 (pwr?)
DD6 5 6 DD9 4 29
5<- DD5 7 8 DD10 ->30 DD5 5 30 DD10
DD4 9 10 DD11 6 31
GND 7 32 GND
DD3 11 12 DD12 8 33 (pwr?)
DD2 13 14 DD13 ->34 9 34 DD13
10<- DD1 15 16 DD14 ->35 DD1 10 35 DD14
11<- DD0 17 18 DD15 ->36 pwr? DD0 11 36 DD15
GND 19 20 KEY GND 12 37
DRQ 21 22 GND 13 38 GND
IOW 23 24 GND 14 39 GND
IOR 25 26 GND 15 40 GND
RDY 27 28 CSL 16 41
DAK 29 30 GND 17 42 GND
IRQ 31 32 C16 18 43
DA1 33 34 PDG 19 44
DA0 35 36 DA2 20 45
GND 21 46 GND
CS0 37 38 CS1 22 47
ACT 39 40 GND 23 48 GND
+V 41 42 +V +V 24 49 +V (bit of a guess around here)
GND 43 44 TYP GND 25 50 (couldn't make out the tracks clearly)
Doesn't really help finding an adapter...