Recieved what I hope is the final proto boards in Monday. Over the last few days I have soldered in all the essential parts. Not the front panel mods. That area is still in development and could change. But all parts necessary for the operation of the board have been soldered in except for the power and data cable for the drive. I have power tested the board and nothing blows up, some chips get warm but no sauna chips and no exploding caps or resistors. Since there are no Sam’s manual for the XF551 and therefor no documented measurements I can check against, that may mean nothing at all, but I am cautiously optimistic.
Next up is the attachment of the power and data cables for the floppy and the installation of the board and drive into the case. Then the next major test is the power up w/o connection to the Atari. Does the drive power up like a normal XF551? Is there backfeed through the SIO connectors etc? I don’t want to fry an Atari computer.
I am using the modern format XF551 to test with. It should prove the hardest to get up and running. What I learn here on this one will allow me to get the original setup quicker. I suppose I could have gone the other way around but I only had enough money to send 1 board format to manufacture. $80 for 5 boards 15cm X 15cm plus shipping. It ain’t cheap.
Next update should come by the end of this next week.
[dropcap]O[/dropcap]kay time for an update. I recieved the modern power supply test board about a week or two ago. Soldered everything in and it is working with a 24V 1.5 A DC wall plugin. So that is a big step for the modern version of the XF551. I am currently about ready to send the alternate osc circuit and the LED test boards to Itead for manufacture. In about two weeks or so when they come in I can test them and if they pass, that’ll be the final phase before sending the complete modern XF551 board in.
Not so good for the original power supply test board. I got the test board in yesterday and finished soldering the parts in tonight. It didn’t blow or let out black smoke but there is no voltage at the drive connector. I know the Atari transformer is working because I can power a 1050 with it. So either I wired the DPDT switch wrong or something else in the wiring is wrong. So it’s back to the schematics to see if I can rewire the test board to see if I can get it to work.
Yipee! It was in the schematic. Had the switch wired wrong. Cut the wrong trace and wired it right. Success!!! Now both the modern and original power supplies are working.
Well here it is nearly Christmas. I have a modern power supply test board coming in hopefully by the end of the week. Put together and tested ok should be a big step towards the final board. The board itself appears to be approaching the size of the original, as I have added things. I wonder how that happened…..:)
A big question remains. I am considering going to a four layer board, but my current board house prices for four layer boards is literally five times more expensive for a small batch. (50 count) So I may have to stay with 2 layer. It might not do much to reduce the size anyway. I am working with non SMD parts for the most part. It would be nice to go SMD, but I see no realistic way I can do that much SMD soldering. My eyesight just will not allow it. I’ve toyed with the idea of having my board house do the SMD assembly, but the additional costs could push the total cost of the board beyond that sweet spot that most Atarians will pay. Kinda defeats the purpose.
Anyway, I have a couple more projects in development too. Those boards should come in this week too. Stay tuned for more info.
Happy Holidays everyone!