Reproducing the mini-Front Panel ...

[Walt Perko]

Hi, 

I'm slowly working on creating a eCAD and Gerber files for a new mini-Front Panel board, based on the Rev. F Don Caprio original mini-FP board.  

So far, I've found a few odd things in the original design and have fixed those.  Once I get the eCAD of the board done, I hope to create a 2nd eCAD for an Octal Switch layout to be more comfortable for us Octal users.  This would also be much more unique from the original mini-FP.  

Don Caprio lost all his design files in his retirement move and so, I'm hoping Don Caprio can get a copy of his Gerber files from his fab company and from that I know I can add my fixes much easier than this long slow process of sketching the entire board from a blank S-100 board.  

I'm using EasyEDA as it seems more human friendly than KiCAD.  Also, EasyEDA has the same parent company as LCSC (component distributor), and JLCPCB (fab & assembly).  

We'll see how far I get into this project, but for now I can show you one of the things I'm fixing:  

IF you look closely, you can see the LED mounting holes all line up nicely ... they almost disappear in the scan of the board behind my vector test cut.  

OTOH, the switch mounting holes do not line up well ... this is because on the original mini-FP board they are not all exactly horizontal from each other ... off by several mils.  

Also, the board mounting holes left and right side are not exactly horizontal from each other, or aligned vertically.  

Since I'm not designing a new board for Don's chassis I hope to get the mounting holes as close as possible to an original IMSAI chassis ... I'll have to work that out with Robert Weatherford who along with another guy have resurrected IMSAI as a Parastream IMSAI.  

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[Joseph Corda]

Walt 

Your are making good  progress .. keep us updated on your progress.. Btw are you going to enlarge the switch pin holes to handle 1mm X 2mm pins yo support the AliExpress supply of switches ? 

Joe 

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[Walt Perko]

Hi, 

I already increased the holes to 2.5mm diameter ... plenty of room for many different toggle switch lugs ... still close enough alignment shouldn't be any problem.  

I have the alignment in EasyEDA setup ... you can see how the original mini-Floppy Panel mounting holes don't line up exactly with standard "ejector" holes ... the little red partial circle is from the vector sketch I made that matches up all the holes on the original Rev. F board.  

Next come placing the ICs, Resistor Networks, Capacitors etc.  The final steps are front and back traces.  

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[Walt Perko]

Hi, 

This is the closest I've gotten to a mini-Front Panel Rev.F schematic:  http://ilvunix.com/chassis/docs/IMSAI_CPA_wJoshNotes.pdf  

I've heard some say the CP-A and mini-FP boards use the same schematic, but I haven't gotten any real confirmation on that anywhere.  

Don's website:  http://s100chassis.pbworks.com/w/page/148514064/IMSAI%20Front%20Panel

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