Looking good Jim.
0, Zero, Nada, Zip-De-Do-Dah, Nothing, Nil
Update:
So its been awhile since the last update, but there has been plenty going on behind the scenes. The rev 3 boards are nearly complete and i have finally resolved all the little remaining niggles. Boards have been tested and working a variety of 80b games. The hardest issue to resolve was a very strange high score store issue. This was finally tracked down to a combination of factors, including what i believe to be a mistake/bad design in the original cpu board by gottlieb. It appears (and thanks to one of my other testers for the added insight here) that the timing of the R/W line from the 6502 is the same as the address lines, so there is no margin, and with the delays in the address decode (which is quite substantial, 3 gate delays or more) things are out of spec when the signal is fed direct. Now, this doesn't appear to be much of an issue with the old 5101 ram, (mainly due to its SLOWNESS), but add in more modern rams and suddenly the issue is magnified, (and yours truly ends up banging his head on the desk for 3 months!!!)
Also the way the non used address lines are tied has a major effect on the address location used for the small amount of bookkeeping storage. On the timekeeper rams that i have been using for an enhanced board version you need to be careful this range doesn't run into the actual clock section of the ram.
Also, with previous scenarios there were occasional bookkeeping value storage issues and non specific errors moving through the totals. And on some games the memory test would report a bad ram. These issues are all also now fixed
Also, the board now properly can use both the timekeeper ram and a regular 6264 ram (as used in most dmd games in the 90s) External battery connection to the included ext bat feed is obviously needed here to retain the saved data. I've uploaded a few pics from the tests in my Gold Wings today..
Its time for a beer
0, Zero, Nada, Zip-De-Do-Dah, Nothing, Nil
I'm a little new to this and your projects. Just caught it on JMP's thread. Do you have licensing issues with what you're doing?
Great work, BTW!
No Issues as far as i am aware, as the board is my own design using off the shelf parts. It is NOT a copy of the original. In fact the original is not even designed that well!. It does not include game code or roms owned by gottlieb or their copyright owners. You simply plug in your existing roms, which you own as you bought the game!
Maybe i should add a note that this projects in not endorsed or affiliated with Gottlieb, Premier or any of their copyright holders. It is 100% english innovation!
We're proud of you Jim and all the work involved in saving some of the older machines.
And it's a British thing, nice one.
Maybe i should add a note that this projects in not endorsed or affiliated with Gottlieb, Premier or any of their copyright holders. It is 100% english innovation!