An X68K Story: From Zero to Expert in XX Days

Started by unixgamerocker, January 04, 2011, 11:08:14 AM

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unixgamerocker

Hi, I'm the new guy that's been making lots of noise on IRC. I recently purchased an X68K Expert. There was no keyboard, gamepad, disks, or anything else, and the PSU was dead. So, I've been scouring the forums and wiki here as well as just googling around to get answers anytime possible, and trying to get the machine off the ground to show it off in a sort of gaming "museum" showcase I'm putting together in a week or two.

I suck at this forum thing but I figured some people might be interested in the story or even just what I'm working on at the moment with it. This post could also serve as a handy guide to some other noob trying to get themselves off the ground without the need to scour too much.

The acquisition story was really straightforward; a guy on a forum I sometimes read posted his X68K Expert in a marketplace thread. He lived in cali and got it with intentions to repair it but didn't. One of my good friends noticed his post on the forum and quickly sent it to me, and I noticed the guy preferred trades to cash. I offered him money anyway, he took it, and he said he'd ship the X68K to me when he got home from school in a few weeks.

Fast forward to the Monday after christmas, and I got a nice christmas package, my expert arrived! It was well-packed, and sure enough, it didn't power on. No lights or anything.

I quickly jumped to Lawrence's power supply mod page and realised I didn't have any power supplies small enough for the mod, so I decided to mod the mod. Basically, I chopped the wires from the original PSU, extended them with some extra wires I had laying around, and then soldered them to the back of an ATX power connector I cut off a dead PC motherboard. Eventually I will mount the connector inside the machine, facing out, but for now it's just kind of hanging out of the back of the machine.

How about some pretty pictures...

The board in the machine, sort of where it'll get mounted eventually:


Solder job on the back of the board:


It lives!


So, now to get video out of the thing. I don't have any nearby electronics stores, so I'll be doing all my ordering online. But again, I have a WEEK to get this thing to do SOMETHING other than power on, so mail order is probably not going to cut it. What do we do?

First, I wanted to make sure video actually worked. If at any point I run into a dead end on the machine, I have to prioritize other working machines. While I'm hoping I'd be able to solve any simple problem, generally speaking, I really just want to keep working. If I can't work on this, I go to the next project (I have an MSX2 and a PC-FX I hope to show off as well). So I quick poked some pins into the video connector on the X68K (green, horizontal, vertical) to see if I could get video, and got this:


Since video was good, I found a PC (gameport) steering wheel that I probably bought for like $5 at goodwill laying around and decided to cut the plug off, then used some grips to pry off the DA-15 male end. Fortunately, even though most joysticks won't connect all 15 pins, they were all in the plug, so I could still use it to solder to. Armed with the pinout from the wiki I soldered each of the little pin cups to some cat5 connecting only RGB signal+ground and H/V sync signal only. I figured orange was close enough to red that I could match the colors and use brn/whtbrn for HV since those are close enough to the colors they use on RGBHV cables. Then I found a defunct VGA-to-BNC cable and chopped the BNC connectors off so I didn't have to worry about the pinout of VGA, and soldered/taped all that up.

The result (X68K end):


I'll be soldering up a bunch more wires to the inside of the connector so I have them readily accessible for access without having to solder to the connector again, because let me tell you, it's a pain in the ass. I'll be filling the connector with some hot glue or something so I don't get any touching wires. I don't have a hood for the connector, yet, but it'll get ordered.

Next was to figure out how to get some disks working with the thing. Problems:
- I don't have any floppies handy
- I'm not sure my X68K's floppy drive works
- I run Linux so omniflop and all the other disk utilities are out of the question

Fortunately, during all of this, I've had some great help in #X68000. I popped on and mdl has a working floppy drive setup. With a little bit of reading and dicking around with setfdprm, we were able to figure out how to write X68000 floppies in Linux with no utilities.

So, now I have to hunt some floppies down, but once I do, I can at least see if my floppy drives work (I'm guessing they're fine but I won't know until I try). If something boots, next step is to wire up a gamepad and then I'll at least have something to show people!

More posts as I make more progress.

Midori

Nice thread, I'm a little envious of your adventure but I'll try to open my wallet some day and make one of my own.

Interesting work on the floppy writing there.

I don't know but this thread might fit even better in the "projectLogs" part of the boards, but it fits good here too in my opinion. Anyway keep up the work and keep on posting!

I have little experience with actually working with X68Ks but it might be worth a shot to open the old PSU and swap all the capacitors in it. Although there is no guarantee that only they are broken, but it would look better if that was the case :-)

unixgamerocker

Thanks!

Yeah, I think I'll keep it here, I'm really shitty at keeping up on forums and I'd like to be, at the very least, a sparse member of the english-speaking x68k scene rather than spreading myself even more thin than I already am. Everyone that knows something about an X68K has really been very helpful and nice so far.

Regarding the original PSU, I may swap all of the components out someday, but the emphasis right now is on speed. This thing has to be packed in a tote in a working state on Tuesday to go to the show, so I don't have time for time-consuming component-level repairs.

Speaking of progress, I FOUND MY FLOPPIES and there are soooo many of them, it's really a great day. So assuming that the disks are good, my PC fdd is good, and my X68K fdd is good, I'll be rocking some games soon!