just found a nice blog post from Elgens Blog under http://elgensrepairs.blogspot.dk. Okay, it's some nerdy techporn, but anyhow. I enjoyed reading it much.
The Fluke comes with a RS232 COM Port, but only my old PC has this one. Elgen post some nice pics for assembly anUSB port.
Find here a copy and paste of his article
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Now in order to start playing with this wonderful machine, I would need some interface pods. But that can take some time to find, so in the meantime, I would try to use the RS232-option to hook up it up to a PC using FIDE. Now I do have an old laptop with a COM-port, but would much rather like to use my lovely Lenovo that is my primary PC, but only has a couple of USB-ports. So I went to evilBay and ordered a cheap little USB-to-RS232 Adaptor. After a week or two it arrived.
In order to use it with the Fluke, I would need a cable too...or would I? Hmmm, the adaptor was easily disassembled by pressing gently on the USB-plug revealing a tiny PCB with both plugs soldered directly onto it.
My plan was to built this into the Fluke and add a USB Type-B plug on the backplate here.
So I started by desoldering the D-Sub from the adaptor.
Next it had to be hooked up to the Flukes RS232 port. The port is attached to the PCB by a 6-way molex connector (only 5 pins in use).
If you press very gently (but firmly) into the holes on the side of the molex plug with a small screwdriver, you are able to pull out that connector. My plan was to "piggybag" these 5 connectors with wires.
Next I hooked up the adaptor according to this diagram. I plugged it into the PC, fired up FIDE, prepared the Fluke and tried to send a sample program. Nothing at all happened on the Fluke! };-S Hmmm, went back and had a read in the Fluke manual and discovered that one should use a null-modem cable and not a strait-through. So changed the wiring according to this diagram instead. Now at least something displayed on the Fluke: Sometimes I got "PARITY ERROR" and sometimes "FRAME ERROR". Tried a bunch of different combinations with speed, parity, number of databits, and start- and stopbits. Still same-same. I decided to let the whole thing rest for the night, as I was also i bit tired.
Next day, fresh in my mind! I discovered a little white marking on the turnwheel to set the RS232 speed on the back of the Fluke (see pic higher above). Until now I had though that the slot you put the screwdriver in was the indicator of the position, but having a closer look at the white marking, I could see the shape of a small arrow underneath it. AHAAAA!!! He cried out loud! I now put the turnwheel into position 7 according to the arrow and presto... I was able to upload my sample program
and execute it
Fantastic! So it was actually possible to communicate with the Fluke using FIDE on Win7 (32bit) and a cheap USB-to-RS232 adaptor };-P Now I could have just stopped there with the USB-wire coming out of the tape-drive hole; but I wanted it to look a bit nicer than that.
I dug up this little PCB from the pile (have no idea what it's for) and a piece of shielding metal (as solder bites on it)
Desoldered the USB Type-B plug and made 2 small wings from the metal piece using the Dremel. I then soldered the wings onto the sides of the plug.
Next I found a nice place for the plug,
made the hole using Dremel and some small files, drilled 2 holes and attached the plugs using small nuts and bolts.
Here is a picture with the USB cable plugged in
and here a look inside the Fluke
All in all I'm pretty satisfied with the result, and I don't have any fuss with messing around with adaptors and null-modem cables when working with the Fluke.
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Great stuff. So far so good. But then he really used also the FLUKE while fixing his 1942 arcade pcb
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In the maintime, I had found that the sound circuit is identical to the one on the original. So by inspecting the schematics (page 3) found at jammacade.net, I could see, that the only ICs left on the bus, was the CPU, the RAM, and the 2 sound chips. Now, if the CPU was knackered, it had to be desoldered anyway; if not I could solder in a socket and have a great chance to try out my new toy, The Fluke9010A };-P So desoldered the CPU and fitted a socket instead.
And now....Fluke-time! (Ooooh, exciting!!! };-P)
The Fluke showed just what I'd discovered myself
So the CPU was innocent. Ofcause, I was not able to do any of the other tests until I'd solved the problem with the stuck data line. The only things left on the bus was the RAM and sound chips. However, before desoldering any of them, I desided to visually inspect the circuit lines of the bus just one last time. Then I found this...
This grounded soldering was very close to the stuck line, and when looking through the magnifying glass, I could see that it had taken a little hit at some point. So I gently made a cut with a Stanley knife to separate the soldering from the line...
And when I booted the game, I had sound again, also with the CPU back in place. };-P
But as I had the Fluke powered up, I did the BUS test
Found the RAM-space via the MAME source
and did the two RAM tests (short and long...beware, the long one takes very long time)
Finally I used porchys great little tool Fluke 9010 Sig Calc to calculate the signature for the ROM and do the ROM test
I find that the Fluke is nice and easy to work with, and that it has a lot more potential than what I've done with it here...I'm so very happy with it };-P
Case closed; I think I'll try to trade this board for some other defectives, as I don't like 1942 that much.
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Great work, no further comments needed.
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