DiscFerret update: PCB done!

Hi guys, I've just (within the last few minutes) finished the "first cut" board layout for the DiscFerret. It's a 160x100mm Eurocard, with all the "inputs" (power and USB) on the back panel, and all the disc-drive interfacing stuff (power and I/O) on the front. Truth be told, it's not much different to the prototype schematic I posted to the list earlier this year... The 40-pin disc I/O connector carries a standard 17-line ("34-pin") Shugart disc interface with all lines wired, four high-speed 5V TTL "user I/O" lines, +5V (low current) and ground. The state of the DENSITY pin (pin 2) can be driven as an open-collector output, or used as an input (depending on the type of drive you're using). There's an external "power output" connector for the disc drive. This is a dual-row 4-pin AMP Micro Mate-n-Lok (P/N 3-794618-4, mating connector 794617-4 with 794610-1 contacts) which carries +12V, +5V and two grounds. Current-handling capacity is about 1.5A per channel, so plenty for most PC-style drives. There are no cop-outs here -- you can pull 1.5A from the 12V bus, and 1.5A from the 5V bus *at the same time* without any adverse effects. I wanted to use the standard Molex floppy drive power socket, but Molex only seem to make one PCB-mount variant, which is the "input" socket (which has a recessed body, but contains male pins -- go figure)... There are also three status LEDs -- Power, FPGA Status and PIC Status. The first is always on when the +3.3V regulator is running, the latter two are controlled by their respective devices. A plastic light-pipe redirects the light from these LEDs to the front panel. Simples! For the curious... Schematic: http://www.discferret.com/temp/discferret_sch.pdf PCB layout: Checkplot: http://www.discferret.com/temp/discferret_main_chk.pdf Top copper: http://www.discferret.com/temp/discferret_main_top.pdf Bot copper: http://www.discferret.com/temp/discferret_main_bot.pdf Top overlay: http://www.discferret.com/temp/discferret_main_tov.pdf EAGLE project files: http://www.discferret.com/temp/eagle/ (you'll need all the files in this directory) Next step is to do a full design review (i.e. print the board and schematic out REALLY BIG and go over them with a loupe), create a Quartus constraints file and test-synthesize the FPGA microcode. But first... it's 3AM and I'm tired. Sleep time! zzzzzz.... -- Phil. classiccmp at philpem.me.uk http://www.philpem.me.uk/