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Rev 1 cartridge pcb received!

The previous blog post detailed the pcb design (and postings before that, the schematic and pinout.) Elecrow was having a sale at the time and was one of the recommended places to try out (along with Seeed and others.) Elecrow had ready to use Design Rules and CAM processing files for Eagle as well.. so being relatively painless to use, and cheap as heck.. had to try them on! (The Design Rules provide a handy reference for the pcb house with the limits of their equipment, so you don't have traces too close to the edge, or unavailable drill hole sizes, or other minutia. The CAM file is a set of macros to help produce the type and style of files they will need to produce the pcb. “Gerber” may be the general standard, but theres a lot of wiggle room in that general arena.)

So without further ado, see the picture; its a very simple pcb design, and is smaller than a credit card (since it is supposed to ultimately slip into the cartridge case for a typical Atari 2600 game cart. Its unlikely I'll be able to afford any actual cart cases, so fitting into somethign common seems the way to go.. but even the crappy flooded out sports games for the 2600 have become pricey of late; if anyone happens across a small cache of dead carts, let me know :)

I wasn't entirely sure what to expect .. rather assumed I completely blew it, or the 'ground pour' would cover the whole thing .. due to complciations with the cam files, or noob mistakes in EAgleCAD or any number of things. Gladly, none of these came to pass.. it turned out very nearly perfect (at least, turned out as I'd designed, and then some.)

Of interest ..

  1. I selected 1.6mm thick pcb, but its on the over-tight side when slotted into the female edge connectors I've selected; perhaps switchign to 1.5mm would do it or perhaps they just need to be inserted and pulled a few times, to loosen up the slot
  2. I thought I had, but apparently did not, widened up the GND and power traces; however for my amperage and voltage needs, this should not matter
  3. I know it is common for a ground pour to be on one side (say, the bottom) (where a 'pour' is filling up unused area with a gnd or voltage, so as to be easier to trace pins to, and to sweep away any signalling interference), but some common options.. ground pour on both sides, ground on one side, ground on one side and power on another … I do know if you have Vcc on one side and GND on the other the whole pcb acts very slightly like a capacitor; I'm told this is a good thing, or something you can ignore, but I'm a little caution about the implications.. so opted for gnd pour on both sides. Means GND is everywhere I'd need so pins just slop into it, but did mean I had to trace vcc out a touch.. no biggy. (On the actual zikzak main board, its much more interesting a question.. GND pouor on bottom makes some sense, but the top has at least a 5V and 3.3V section… so a pour is goofy, unless I keep all 5V to one side and all 3.3V parts to another, etc. We shall see…)
  4. The actual job by Elecrow, and the materials used, seems top notch; its a sturdy tight piece of work with beaitiful traces and a nice lively green. I'm quite pleased. The turnout was quick .. given they were doing a sale, I worried they might be backed up in a glut of orders, but they received it on a Friday, and send it off for shipping I think the Wednesday following; It was only $12.99 for 10 pf them, but due to excitement I went for DHS delivery just this once instead of waiting weeks for slow delivery … so I had it on the Friday! A week turnover, door to door. Sweet.)

I'll definately try Elecrow again, though Seed gives you the different pcb colour choices ….

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