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Vanløse, Copenhagen, Denmark
Mathematician. Working programmer/system developer. Nerd. Married. Father of 3.

28.8.12

Scope dead but a new (old) one acquired + nice gear

Last week my good old scope (Trio-Kenwood CS-1022 20MHz) decided that she'd had enough of me and simply stopped sweeping horizontally. It happened when I accidently had her turned on for two full days. When I discovered that she was on, this was the sight I saw:


(the dot looks bigger in the picture than irl). I think it might be the horizontal deflection coil or the circuit driving it. I will at some point try to repair it, I think.

Luckily, about 1 week before this incident, I'd been contacted by one on my old friends Jarl from my days of studying math and computer science at the university. He wrote that he had some old gear stashed away in his basement, and that he would gladly donate it to me, if I could find any use for it. It was an old scope and an old EPROM-programmer. The timing couldn't have been better };-P

The following weekend we'd hired a car anyway, so I drove to Jarls place to get the goods. We had a nice nerdy chit-chat about 'the good old days', EPROMS, C64, The CoreBoot Project and a lot more };-P

Then we both drove back to my place, so he could have a look at my own little repair workshop. We tried to connect the scope (Telequipment D65 15MHz), and she works like a charm with a nice crisp and steady picture:


As a pure bonus, she has a really nice retro-look; I'm back in the arcade-repair business! };-P

Now as for the EPROM-programmer (Sunshine EW-704), it connects to an ISA-slot. I didn't own any PC with ISA-slots, but Jarl was kind enough to donate me his old 486DX2 as well. We couldn't get in contact with the hard drive for some reason, but as the software for the programmer is written for DOS and consists of only one exe-file, it fits nicely on a DOS bootdisk.


The external module with the 4-gang of ZIF-sockets fitted nicely in the disc-slots on the front of the PC, so I choose to mount it there };-P


This programmer actually does Vpp=25V (something not possible on my Top2005+), so now I can program those old 2716 and 2732 EPROMS as well; totally jawsome };-P

I really owe Jarl a big thnx for the kind donation...really helps me keeping them old boards alive };-P

7.8.12

Mitchell Funky Jet Bootleg Repair Log

Well, some repairs are very easy, and this one happens to be one of them...in fact the hardest part of this rep, actually was to get the photos right for this log.
Well I was given this board, along with some other defective ones, as payment for burning some EPROMs for this dude I know from spille-maskiner.dk. When first hooked up, the game seemed to play fine and the sound was fine too. But at the intro (where the two main characters of the game fly past each other) and at the stage select screen the graphics was messed up.


During visual inspection of the board, tahn infacts looks to be in pretty good overall condition, I noticed an IC with two caps soldered over the top of it. One of them had one pin broken loose from the IC.


(here I have yanked it a bit to make a point };-P)
I pressed it against the IC pin with my finger, and


Fired up that old soldering iron...a few drops of solder...


...and VIOLA...board fixed };-P