Cloning an MIF ISA Card

[Bryce]

Hi all,
PeterNY was looking for someone to build him an MIF-IPC-A card here: https://www.amibay.com/showthread.php?t=56345
So I thought, why not? Nice mini project. All the details I need are there, just need to get the parts. This morning the last of the parts arrived, so I've set up this thread for Peter (and any one else who's interested) to follow the project. The parts can bee seen below. The PCB was ordered from the other bay from a guy in Thailand. The back-plate didn't come with the PCB, but luckily, the connector positions are exactly the same as a standard RS232 backplate, which are easy to find. So it will look like a proper card when finished, without me having to hack away at a blank back-plate.
Unfortunately, I own neither an ISA PC nor an MPU thingy to test it with, so it's going to be a case of building it "blind" and sending it to Peter for testing. I've ordered enough parts to build two of them, so if Peters doesn't work, I can check my copy here, which might help to find the problem (I hope).

 

[keropi]

amazing, please keep the pics coming Bryce

 

[PeterNC]

Looks great! I look forward to testing the first prototype. Thanks again Bryce!

 

[Xanxi]

Great project.
I don't have any ISA PC but i do have ISA Amiga and bridgeboards: that could be a direct way of testing it for you.

 

[keropi]

^ you can't really test the card without a MPU401 Break-Out-Box and some midi synth connected to it , the BoB holds all the important stuff inside, the ISA card is a simple interface one

 

[Bryce]

Due to a small boy (2.5 years old) who seems to think that my "raison d'etre" is to entertain him, it doesn't look like I'm going to get all that much done today. So here's a few pics of what's done. I've positioned the ICs (same positions as the real card here: http://4.bp.blogspot.com/-ZepyfIOh6Yo/Ub4TejIsiTI/AAAAAAAAAbU/Qzh0TmbMlyc/s1600/20130615_171440.png as I assume that they at least spent some time working out where the best positions for routing are) and I've wired up the GND to all ICs and have started on the VCC. I intend wiring all power on the lower side and all data wires on the top side.

Bryce.

 

[PeterNC]

Looks great already! I have an almost 2 year old and a 4 month old son so I know how distracting that is.

 

[Bryce]

Quick update. It turns out that the back-plate I've shown above doesn't fit the card properly. Although the plate lines up perfectly with the 25pin and 9pin connectors, the plate is positioned too high on the card. However, it looks like a plate with a single 25pin hole in the centre will fit. I'll search one out from my box of PC scraps later and confirm this. Luckily I only need the 25pin connection

Bryce.

 

[PeterNC]

Excellent Sir. In case you need me to pick up super cheap PCBs on eBay and mail you 2 backplates let me know.

 

[diskers]

Hi guys,
I know a company here that can make one or two layer PCBs from eagle format and as I remember well also from KiCad format at quite reasonable prices and in a quiet good quality as I have some midi modules this project seems quite interesting to me. Anyway let me know the exact dimensions of the PCB and I will ask the prices and the minimal order (I ordered from them one day a single layer PCBs and payed 12 or 15€ - they are counting at
1 dm²).

 

[Bryce]

I also have PCBs made for me quite often, but I didn't think there'd be a big enough interest. I don't really have time to make a batch of PCBs at the moment, but I can create a Layout for you if you want.

I found a backplate with a centred 25pin hole. It's very close to where it should be (about 1,1mm too low) but it should be within tollerence, so it might work ok. I'll look for a second one later.

Bryce.

 

[keropi]

I want to make a small 8bit ISA card of my own, I am stuck on the design though... I downloaded eagle/kicad/diptrace in hopes that there is an isa template or something but sadly I could not find one... any comments on what software to stick to and try to learn Bryce?

 

[Bryce]

Eagle in the Freeware version won't work. The freeware version has a PCB size limit that is smaller than an ISA card. KiCAD is probably a good choice. I don't use it myself, but I've heard many people mention it positively.
It allows you to make your own parts, so creating a template shouldn't be that hard.

Bryce.

 

[PeterNC]

Once we confirm a prototype works and Bryce designs a layout we can discuss next steps. The next challenge is finding MPU-401 BOBs: I have found 4 so far since January.

 

[diskers]

@Bryce it would be fine. If anyone will be interested I can order some PCB for him too.

 

[Bryce]

Oooo look I didn't have time to get to the soldering iron, but an hour waiting at the airport (with my laptop) was used effectively. These are both just draft versions, neither the schematic nor the dimensions of the PCB have been checked. But it does look like (contrary to what I said above) an ISA card (at least a mini one) is possible with the freeware version of Eagle.

Bryce.

 

[keropi]

'nuff said

 

[PeterNC]

Wow! You are a true engineer Sir!

 

[keropi]

Bryce, did you design the card from scratch? even the ISA pins?

 

[Bryce]

Bryce, did you design the card from scratch? even the ISA pins?

Yeah, I had to, there isn't an ISA edge connector in the standard libraries. All the other bits are there though.

Bryce.

Btw: I gave KiCAD a quick try tonight... It's ok, but it's miles from Eagle as far as user friendliness and ease of use is concerned. If you are only doing relatively small PCBs I'd definitely recommend Eagle above KiCAD. I've downloaded DipTrace too, but I haven't had a chance to try it out.