DIY RAM EXPANSION

[dilwyn]

What I want to know is.... Who is Dawn?

She's living under my Gold card.

IIRC girlfriend of the guy who worked with Stuart Honeyball and designed both the GC and SGC PCBs, whose name escapes me...

Mike Tomlinson.

[tcat]

Hi All,

I have started my PCB design, as it seems a better option to using prototype backplane board.
I seem a little bit confused about DIN expansion connector pinnout.
QL Concepts Guide gives such pinout as MALE, I guess I need to put FEMALE in the design, but there is yet another view such as solder side, connector side.

My design software offers these two DIN pinouts, it is top view solder side.
Can anyone help to choose?

Many thanks TCAT

QL DIN pinout

[tofro]

Dave,
according to the document on the Reichelt site, the "a" row is always the bottommost on the connector and the pin row closest to the card edge. Your picture seems to show the non-angled connector pinouts - They are slightly different and have the mounting (screw) between "a" and "b", but closer to the "b" row. The angled ones have it outside (towards card edge) of "a".

Hope this doesn't confuse even more....

Tobias

[tcat]

Tobias,

"A" pins are on the edge, I was afraid so.
Meaning that "A" row contains most of the address and data line pins, this makes it difficult for track routing. To reach address and data pins on the PCB the tracks would have to go between many "B" row pins.
Correct?

Many thanks so far.
TCAT

[Dave]

Hi TCAT,



I have also had this struggle. Mostly because the labels do not match the markings

The square hole is pin 1. That usually means pin one of row A, which is the row closest to the board's edge. In this case, the square hole would go at the bottom/front of the board, nearest the board edge.

However, if you're not working from a schematic, as long as the positioning is correct it really doesn't matter.

[tcat]

Just to double check.

This is what I see when looking inside the QL slot.

From left to righ
"B" row top, GND, D2, D1, D0, ...
"A" row bottom, GND, D3, D4, D5, ...

Correct?

TCAT

QL expansion connector FRONT view

[prime]

Just to double check.

This is what I see when looking inside the QL slot.

From left to righ
"B" row top, GND, D2, D1, D0, ...
"A" row bottom, GND, D3, D4, D5, ...

Correct?

TCAT

QL_expansion.jpg

No I think that's what you would see looking into the connector on an expansion card CARD (or from the QL side of the connector. Looking into the slot it would be mirrored left to right do GND and the data lines would be on the RIGHT.

Cheers.

Phill.

[tcat]

Dave, Phill,

Expansion card edge with connector imprint, TOP VIEW, should look like that.
Correct?

Thanks so far.
TCAT

QL expansion card edge

[Dave]

Yes, the two ground pins 1a and 1b are at the bottom. The three VIN pins are at the top, 32a and 32b, plus 31b.

I made this handy laminate that I use with a dry erase marker when hooking stuff up - great for keeping track...

QL on right, thru-conn on left.

[tcat]

My first ever PCB, 3 vias in grey, unconnected pads in yellow.
I skipped prototype backplane, relying mostly on forum advice, how certain can I be, it will work in the end?
Thank you ALL so far.
TCAT

ql520 ram pcb