Recent content by Asayuki

I personally use an Optivisor. This little fella is daunting cheap on amazon, but it's extremely useful (at least to me). First of all you don't need to adjust anything. It follows you automatically every time you change your viewing angle while still keeping the lenses at the best position for...

Hard to explain it better than this :D

They are not readable from the photo, but almost certainly they are 100nF 50V. Do not expect a cigar on this, however; the audio section if I'm not wrong is around the center of the board.

I have no idea where the resistive network you are talking about is placed, so can't answer that without more precise information. But, as far as I remember, the bios will try and adress all slots one by one searching for an header in the P1 roms. If the header is found and satisfies the liking...

Redundancy is a blessing: if one psu goes banana then at least half of the system will be working. If you have one PSU for two boards, then you might fry two boards for the price of one psu if that one dies in very bad way... Even with a better PSU I wouldn't do it anyway.

I'm glad you found that little bugger. Well done, man! :)

Remember: this method of dumping PALs in general (and GALs which are designed to be compatible with them) is useful if and only if the PAL/GAL has no register inside or the register isn't used. If the register is used, then there is no way to make sense of the output data.

Very good for a first timer. Welcome on board! :D You're now kind of framed, as we wanna see more ;)

Since you know how to dump roms, and you look very determined in solving this issue, you might find the following useful: 1) The datasheet of the GAL16V8 is here. Now that GAL has internal latches which make it impossible to dump, but if it has been dumped for MAME then chances are the register...

At your service :D

Hi, as I am lately confronting with yet another very difficult repair (one which still is far from complete), as well as with another project of mine, I really needed some diversion. Therefore I had a look into a board I just snatched and hoped in a relaxing evening. Although not exactly easy...

You absolutely do have a ground loop around. But the problem is not the loop itself; it rather is the way the grounding is routed. Too close to a strong AC source (mains trafo, crt joke, lopt, etc. etc.) and you get exactly the disturbance you are talking about. Relocating the cables might solve...

Either the test is failing but you get to see no message, or the code crashes right afterwards. In either case the first step should be that of identifying which board is defective (if any). Do you have other A or B boards to try with?

I think your issue resides in the MC-1091 custom SIP module. ...it even looks deeply scratched on top of one of the ICs... As a confirmation, you should try beeping the START1 pin to the module; if it goes to one of its pins then the module is very likely broken. You see, these things are made...

I know EXACTLY what you are talking about! ;)