N8VEM S-100 backplanes and S-100 prototyping boards

Ethan Dicks wrote: I know you meant this off list, but it seems relevant to reply on list. Quite frankly, for through hole stuff, I'd be surprised if any proto-house does a bad job, so I'd get a few quotes and go with the best offer. If you want a reference, I know some use 4pcb.com (http://www.4pcb.com/instant_quote/), and I can recommend OurPCB (www.ourpcb.com). In the quick quotes I ran, it looked like $1.50/sq in was pretty std across the board. I have not used Sunstone (https://www.sunstone.com/quoteValueProto.aspx), but I've heard good things there as well. If you have a couple designs you would like to run, you can do better on per-board pricing by doing panel purchases. I know silvercircuits.com used to offer a 2 8x10 panl services without silk or soldermask for $78.00, and I usually fit 4 or 5 designs, 4 board yield at that rate. Thus, I got 16-20 boards for ~ $5.00/board (including shipping and the upcharges for adding designs to the panel). However, once you get past a nominal quantity of boards, I'd recommend doing a prod run. You have more options, and places like OurPCB can run a 3x4 for about $2.00 a board with a $50.00 setup. By the time you pay for shipping, you're probably at 65-70 dollars for a dozen boards, but later runs incur no setup, just shipping. OurPCB is in China, and boards come in 10 business days for me, 5 if I pay a premium. Nowadays, I don't even run a prototype. I just do a prod run after a good desk check of the design. Even if the boards are not perfect and I decide to respin, they are often useful, and the money is easily recouped. For instance, this Spring, we ran the 64NIC+ (100 units). After I got the first boards manually assembled, I found a few bugs in the design, so we decided to respin. However, since the 64NIC+ includes all circuitry for a std C64/C128 cartridge (EPROM socket and switches/jumpers), the 100 PCBs can still be used as regular game carts without any mods, and it's trivial to mod them to fix the bugs. In short, don't automatically shy away from a prod run just because you have low quantities. It may actually be cheaper to do it over the proto-run. I also use OurPCB for assembly, and they're a good deal at $0.0178/pad assembly cost. I quoted Sierra Circuits in the states on the same job, and they were 2.5X for the mylar stencils, 8x for the bare boards, and 3-5X on assembly. The latter two stump me, as I know much of PCB fabrication and SMT assembly is automated. Yes, it's not USA. I'd be willing to pay a price premium for US work, but 150% or so, not 500-900%. At the latter rate, I simply cannot afford to create products for a small niche market like the CBM space. I can't speak ill of any other companies, but I've been very impressed with OurPCB's willingness to work with me on the small orders. They've been very good at assembly, and very communicative. If you're a night owl like myself, you can get real-time feedback via email or Skype with them (they are 11 hours ahead of me, so they are starting their day at 7PM local, as I recall. Still, I can make fast changes from 7PM to 2AM, when I finally pack it in) Jim -- Jim Brain, Brain Innovations (X) brain at jbrain.com Dabbling in WWW, Embedded Systems, Old CBM computers, and Good Times! Home: http://www.jbrain.com