Thursday, 2 April 2015

Vaporware rendered in glorious 3D

Here's a very, very preliminary 3D rendering of the flash cartridge PCB.

The large euro connector at the bottom mates with the system adapter boards we designed and prototyped last year, allowing the cart to be used in both AES and MVS systems. The connectors down the right (near) side include serial debug connector, JTAG in/out chain, external power and cartridge PCB interconnect cable. On the left (far) side is the SD card slot.

The prototype is intended to be programmed stand-alone from the SD card before being inserted into the motherboard. A complete cartridge comprises 2 PCB's and the interconnect cable enables both to be programmed from the one SD card image.

Early days yet and features are still subject to change.

Wednesday, 1 April 2015

Laying it all out

Some pretty exciting (for me, anyway) news - I've been informed that layout is now complete on the flash cartridge!

I can assure you that this is NOT an April fools joke; at least if it is, I've been fooled as well!

So what does that mean from here? Well there's the tedious but necessary review of firstly the schematic (including checking FPGA pin assignments) and then the PCB, including footprints, layout and physical factors. This is a task ideally performed by someone other than the engineer that put it all together; namely, me. It's not fun at all, but ultimately a lot better than having to re-spin and manufacture a 2nd prototype run.

That aside, work-wise it probably couldn't have come at a worse time. I can't see us being in a position to be able to proceed with prototype manufacture for a few months yet, but hopefully no longer than that. In some ways the delay may encourage more rigorous review. Years ago with our first homebrew design we could only afford a single prototype run and we were so paranoid we reviewed the design to death; the result was a perfectly working board with zero patches!

Until then, I'll get stuck into the comprehensive review, and also enlist my former co-conspirator to review the top level design. Realistically it would probably take me at least a month anyway, given my work and family commitments, so perhaps work will sort itself out in time.

I'll post some eye candy - a 3D rendering of the PCB - in the next few days.