Bally -35 "Heathkit" like board from Homepin.com

HHaase said:
Then a single-solution power supply as well, but with some filtering of the 5v, more robust parts, status LED's and test points, and board mounted fusing instead.

-Hans
Click to expand...

Excellent idea! Some kind of over-voltage protection/shutdown would be needed to prevent cooking the chips on the gameboard.

Both versions of the power supply board use common Molex KK .156 connectors. The female power connector from the power transformer should get re-pinned with all Trifurcons for sure to prevent burning up.
 
KenLayton said:
Excellent idea! Some kind of over-voltage protection/shutdown would be needed to prevent cooking the chips on the gameboard.

Both versions of the power supply board use common Molex KK .156 connectors. The female power connector from the power transformer should get re-pinned with all Trifurcons for sure to prevent burning up.
Click to expand...

I'd love to get some photos of these boards actually installed in machines, to see how true to the original dimensions I have to stay. For instance, could I get away with vertical .156 connectors? or do I have to keep the right angle pieces on the power supply?

I also think I'll start up a fresh thread about this, we've hijacked this one enough LOL

-Hans
 
HHaase said:
I'd love to get some photos of these boards actually installed in machines, to see how true to the original dimensions I have to stay. For instance, could I get away with vertical .156 connectors? or do I have to keep the right angle pieces on the power supply?

I also think I'll start up a fresh thread about this, we've hijacked this one enough LOL

-Hans
Click to expand...

There is at least one good picture of the power supply on IPDB:

http://www.ipdb.org/showpic.pl?id=4116&picno=32967&zoom=1

EDIT: That looks like a series I power supply based on the schematics.

You definitely won't want to design a board that size just so it will mount nicely. Board space is not cheap in small quantities. Looking at the power supply schematics they're ridiculously simple so you should be able to come up with a much smaller board.

They used different transformers between the 2 systems but you could still design a single replacement power supply board. You would just need connectors for both types.

The only real question is how many people will buy one. Designing/building it is the easy part. Breaking even on the cost will be the hard part.
 
Last edited:
Lindsey said:
There is at least one good picture of the power supply on IPDB:

http://www.ipdb.org/showpic.pl?id=4116&picno=32967&zoom=1

EDIT: That looks like a series I power supply based on the schematics.

You definitely won't want to design a board that size just so it will mount nicely. Board space is not cheap in small quantities. Looking at the power supply schematics they're ridiculously simple so you should be able to come up with a much smaller board.

They used different transformers between the 2 systems but you could still design a single replacement power supply board. You would just need connectors for both types.

The only real question is how many people will buy one. Designing/building it is the easy part. Breaking even on the cost will be the hard part.
Click to expand...

I don't expect to sell many, and I don't expect to break even. I expect to use it as a learning experience to work toward more complex projects.

I do have ideas for that extra surface area on the power supplies. Mostly for fuses, some for the different connectors/jumpers as needed. Though if the mounting allows it, I'd love to reduce the size. All depends on design of the backbox itself.

Going to have to also track down the schematics for that Lintronics LED display, that was an outsourced part that isn't in the schematic book.

Oh, I started up another thread on this topic, so I'll mostly be replying in the other one now.

-Hans
 
That's a fairly considerable difference if you look at the schematics. Both CPUs are 40 pins but that's about where the similarities end and the pinouts are totally different. That makes using 3870 (series II) CPUs in 3850 (series I) games impossible.
...
I couldn't find a datasheet for the 3851 PSUs but I didn't look too hard. You're definitely going to need that to figure out how to initialize and drive them. And here I thought the 6821 PIAs were a pain to figure out. I have a feeling these will be even more evil.
Click to expand...
I've done quite a bit of work on different F8 systems using 3850s and 3870s. Both have the same opcodes, but the 3850 is a multi-chip system and the 3870 is all-in-one. The oddball thing about F8 is that it does not typically have an external address bus. The 3850 outputs 2 clocks and 5 signals that all other chips must track to keep their internal address busses in sync. The 3851 is a "program storage unit" - a ROM, but using those signals instead of an address bus. That makes dumping it a challenge. There is a "static memory interface" IC that provides a standard address bus so that regular EPROMs can be used with a 3850. The 3870 has ROM built-in, but no simple way to dump it. In working on the Channel F and VideoBrain systems, as well as a stand-alone chess game, I've figured out how to dump 3851s and 3870s, so if you ever get to a point where you need them dumped, let me know.

Sean
 
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