ProtoCache1 - IIsi/SE/30 PowerCache Adapter Prototype Development

[Themk]

PCB cost for 14cm*12CM... Based on 4-layers, 1.6mm thickness, and... the usual specs.

NOT LEAD FREE. If we want RoHS compliance (only applicable for the final version, and even then I still want to use tin/lead solder) it will be more expensive. I should have mentioned that earlier, but, for the purposes of prototyping, we don't need RoHS compliance. (And not even for the final production version...)

Here we go:

From SEEED:

$118.76 for 10 boards, following the specs above. 5 @ 98.60, 20 @ $159.08

PCBShopper, 10-quantity, same specs as above:

PCBSHopper.pdf

 

[Themk]

And while I'm at it, I should look at some production costs too for you:

If we go through SEEED to make a production board, following the specs above:

50 @ $304.44, with 100 @ $493.44

PCBShopper, same specs as above, except now 100-quantity:

PCBShopper-4layer-100.pdf

If we have to go to a six-layer board (I sure hope not):

100 @ $786.00, 50 @ $531

PCBShopper, same specs, but now six-layer (and 100 quantity):

PCBShopper-6layer-100.pdf

Just some interesting numbers to think about [] ]'>

EDIT: Yay, this post pushed it to 4 pages now!

EDIT 2: I wonder how many boards we will have to order. AKA, I wonder what the interest in this project is...

 

[Trash80toHP_Mini]

At those prices the ProtoCache1 spec has just gone from two to four layers and there's no doubt in my mind that the production board will have six. The benefits of power and ground planes are not to be sacrificed, especially when you can sneak a few really pesky traces onto them. [] ]'>

 

[Themk]

Yeah, six layers is a good idea.

I guess I was just thinking about the cost, but, when you do the math (786/100) you get a very reasonable $7.86 per board. Six layer it is then!

 

[Trash80toHP_Mini]

One step at a time, gotta get this working first and that's still a considerable set of hurdles to run and one pole vault when it comes to PAL development for the project. It's heartening to see my pessimistic parts cost estimates falling into line from a high, but "more reasonably priced" alternative to a much more reasonable level.

Now to actually get it done if possible. I should probably get a IIci board, I don't even know if my PowerCache works yet and I'll be wanting to verify that it still does many times over the course of development.

 

[Trash80toHP_Mini]

First pass at tightening & tidying up the four layer PCB. Moved connector back into the add'l centimeter for elbow room. May be able to drop the height by another centimeter. Clearances for using the RCPII/IIsi VidCard without interference with the bare Chassis would be my primary concern at this point.



ProtoCache1-4Layer-B-000.PDF

 

[Trash80toHP_Mini]

Taped up to the TPD Card the printout of the ProtoCache1 form factor is lookin' good to go! I could probably shave another Centimeter off the height or add a second passthru, but that'd throw it out of KISS compliance.

Obviously there won't be a floppy drive cage on board and most of the chassis side panel will be excised when the time comes. Video card will fit just fine in a standard or RA connector in horizontal or vertical orientation. Time to mull it over a while, finalize the design and then get the prototyping blanks made.

Next up is tracking down all those pesky pinouts and making sense of them for experimentation in the meantime. I wonder what the many failures will look like on the SE/30's CRT once/if we get past the chimes of death stage. h34r:

 

[Trash80toHP_Mini]

Parts list, goodies on the slow boat:

Wire Wrap Headers



2x20F RA Header for GAL interface prototyping daughtercard



:

 

[Trash80toHP_Mini]

PowerCache1 EuroDIN connectors: listing is top to bottom on PCB:

Wire Wrap PDS Passthru Connector



Also replaces wire wrap pin breakout for PDS connector at bottom, allows for initial connection integrity test.

IIci Cache Slot Connector: Candidate for Passthru on production board (if and when, fingers crossed)



DiiMO form factor PDS Passthru: alternate connector on the if and when wish list



PDS Connector: candidate, still looking for a bolt down part, though board lock will do. I think I've seen bolts on just one PDS connector. The LCIII adapter's IIci connector and they're only nylon, so they're unnecessary, but nice to have for prototyping.



Very glad mouser has these parts available, looks like DigiKey dropped EuroDIN120 as stock items. Minimum quantities would be a major PITA. Hacking three 96pin NuBus parts to make a pair of 120pin PDS parts is a PITA,  a relatively minor one by comparison, but definitely best to be avoided. Pricing is at the low end of my conservative estimates, something like $7 per. with three or four required, again hopefully/if and when.

Since I wanted these pics handy for better visualization, I imagine they'll be a bit helpful to lurkers. ;D

p.s. If anyone knows anything about adding line drivers that would allow for a pair of passthru slots to be implemented, PLEASE chime in.

 

[Themk]

awesome, regarding the last one, board lock will be fine. Mounting bolt holes per apple spec are the same for the board lock version, and based on my 3D model of the board lock connector, will work just fine. It snaps into the board, and will hold it in place well enough not to worry.

DigiKey dropped EuroDIN120 as stock items

Did something change from when I was looking at it 2 weeks ago?

I'll shoot you the PCB layout I have so far, if that would be helpful to you.

Yup, we will probably use a pair of those connectors you mentioned 2nd. One problem I see with a DiiMO style cutoff, is that PCB houses want the diminsions of your board as a rectangle (l x w), so doing a cutoff will have some major cost implications. While they will cut it like that, you will have to spec a board size large enough to cover that, which may not be as cheap as just a straight rectangular board.

 

[Trash80toHP_Mini]

Already factored into the spec! [] ]'>  DiiMO's angled cutoff's not really a problem. Just add enough holes without pads/plating to the drill list a/o copper strips to the surface layers with score lines for snapoping sections off. That's what I'm planning for the clearance notch behind the PDS connector, except I'll be using razor saw cuts to make it neat and clean for the inside corner.

Anything you've got might be helpful. I'm taking a breather to mull things over while I play Paladin bar puzzle.

 

[Themk]

Anything you've got might be helpful. I'm taking a breather to mull things over while I play Paladin bar puzzle.

Okay, great. You deserve to take a breather, and the Paladin project is certinally going to be an interesting one.

 

[Themk]

Just a couple of quick renderings of the right angle male 120-pin PDS/EuroCard connector with board lock, which will be used to attach the card to the logic board.

Straight-on front:



Straight-on back:



Oblique front (as a bonus you can kinda make out the AMP lettering that will be on the final connector in the rendering):



Oblique back (sans ray-tracing rendering):



As a bonus, I made a card using Apple's spec with the RA connector down at the bottom:

 

[Trash80toHP_Mini]

Well, I've piddled most of my day off away playing in Illustrator, but sometimes that's the best way for me to relax. Feels good! [] ]'>



I've shaved another Centimeter off the height of the PC2/II/whatever PCB. Run the numbers again for 11cm vs. 10cm height. I have a suspicion that scrunching it down to 10cm will yield significant cost reduction. I've got enough slop in the design to get there if I reduce size/width of the silk screen layer pinout legend. If it'll free up money for parts and a batch of daughtercard prototyping PCBs I'll definitely find a way to do it.

ProtoCacheII-Alpha-100-C.PDF

ProtoCacheII-Alpha-200.PDF

 

[Trash80toHP_Mini]

Never mind the 11 Centimeter Quote, I smooooshed it down to 10 Centimeters already!



It was rebuilding a simplified, consolidated file that took so long earlier, this was a breeze. I hope it's significantly less money, couldn't resist. [] ]'>

ProtoCacheII-Alpha-200-C.PDF

ProtoCacheII-Alpha-200.PDF

 

[Themk]

10cm by 10cm AKA 100mm by 100mm, fantastic!

Well, if you go to SEEED, you can get 10 four layer boards for only $50. Pretty good deal, works out to be $5/piece.

Six layer boards are still in the $300 range from SEEED

There's not much to see from PCBShopper, other than it appears that ALLPCB can get you out the door for $50 too, but with shipping included in that figure.

 

[Trash80toHP_Mini]

Nope, 10cm x 14cm. Remember, the connectors can't possibly fit within a 10cm footprint, much too wide.

 

[Themk]

Whoops, not thinking obviously! :I

 

[Themk]

In case you are wondering "How did the clueless id10t not remember that?", well I think I just got in a little bit of a rut:

Run the numbers again for 11cm vs. 10cm height.

Never mind the 11 Centimeter Quote, I smooooshed it down to 10 Centimeters already!

I should have realized that those numbers would have never worked! Poor data validation on my part.

 

[Themk]

Wait,

That says versus, not by. Wow, where has my mind gone?

At the rate this evening has gone, likely another error is going to pop up, but, well, let's give this a shot:

14cm by 10cm:

SEEED has boards @ 109.80 for 10, 4-layer, the usual specs.

Which turns out to be a pretty cool eleven dollars per board.

A cursory glance at PCBShopper reveals that ALLPCB will only be $59.23, or 5.92 per board.

Someone debug this post for me [] ]'>