Hail to Galaxian... by Namco!

[level42]

Not too much hacks on the back side....one wire already loose...

Also: the pins look like this chip has been soldered, could be because of the piggy-backing but maybe they also changed the original chip. Not to obvious, but do have to check to make sure.

All in all this should surely be doable !

[PaulSwan]

It looks like a reasonably standard mod to expand the ROM and RAM - hence the extra set of 2114's on top and a bunch of hacks on the address decode. Remove all the extra chips & wire hacks then repair all the track cuts and that should get you back to a base Galaxian. You're still missing the original ROM daughter board but you may be able to use the one you have already instead (if you're not going multi-game or single ROM).

The trick is spotting all the track cuts on both sides - when I did mine it took a couple of passes to spot them all.
Paul.

[level42]

Thanks Paul !

Crap I forgot about the daughterboard ! However, I don't need it as I want to install Macro's multi-Galaxian kit on it which I already had on my Bally-Midway machine.

Yes those track cuts are not going to be fun, I actually hardly noticed any but of course they must be there.

Another thing: did they remove the heat-sink on the top right corner ? Seems weird. It looks like they hacked the voltage input (to DC) though.

By the way, Macro's site has a load of great tips about Galaxian hardware and this one is really useful for this job:

Insert a test rom

Test roms exist for Galaxian and Pacman, and possibly others. They are useful, since they don't rely on the rom daughterboard working and these may have problems on their own. For a 2716 Galaxian memory test rom, click here, for a dedicated galaian tester, see the 'Test Board' information on the menu at the top of the page. Remember to make sure that you have galaxian graphics roms fitted, since the test roms may make little sense with other graphics roms. (They definately do not work with Moon Cresta graphics roms)

So, we should "get away" without a daughterboard.

Found this info on this page:
http://www.arcades.plus.com/galaxianfix.htm

[level42]

1h and 1k are the graphics ROMs right ?

In that case, in what socket do I have to put the test-rom ?

[level42]

Did this before but I IDed the ROMs again and the game it's converted to is Tazz-Mania by Stern.

Anyone ever seen one of these ?

https://www.youtube.com/watch?v=gV5qDopRGuc

[PaulSwan]

Based on what Macro said, it's likely you can remove the daughter board and put the test ROM into one of the 2 program ROM sockets directly on the board. I've never used it myself as I added Galaxian to my Arduino ICT instead:

I put Macros multi on that one as well
Is it running the Tazz OK? If not, it might be worth trying to fix it first and then reverting the hacks so you know you're starting with a good worker.
Paul.

[level42]

I don't know, I've never powered it up.

But indeed, this is the plan

What is that arduino doing, providing various ROM sets ? Pretty cool !

Thanks to Jonhughes from UKVac I received some excellent pictures of the NAMCO version of the Galaxian PCB

I'll link them here, can't attach the full size one's, if anyone needs them let me know.

[level42]

Clearly, the heat-sink is missing on my board indeed.

I remembered I still had a heat-sink laying around. I think I might have bought this when I was still at school for some project but never used it 

It's a bit too big on the sides, but I should be able to saw two fins off on each side, then it fits. Also need to drill the holes of course

[PaulSwan]

Cool, BTW, that board has 5101 where the 2101's should be. I'm surprised 5101 would work here - they are pin compatible but 5101 are CMOS and very slow compared to NMOS 2101. The Arduino does RAM, ROM and IO tests etc., sort of a cut down Fluke.
Paul.

[level42]

Yeah I noticed they were 5101s but didn't realize that they were CMOS. I know I need 2101s or 9101s.
I'm pretty sure I should have some since I bought RAMs for Centipede before just have to find them

I have no idea what speeds are going on on those RAMs so maybe the 5101s are still fast enough to keep up ?
I asked Jon on UKVac if the board works (trouble free).....

Further I need 3 74LS259 (or 74HC259, two are on Jon's board) for positions  9L,M,N where the extra daughter board is now.

If anyone has these laying around let me know

I also noticed there is one heatsink missing on the chips on the far edge of the PCB but I still have some of those clip-on heatsinks I used for my Ms.Pac.

[level42]

BTW cool work on that Aduino.....any plans on making it available ?

Sounds like it does the most important tasks of the Flukes and I can imagine people would be interested.

[level42]

Heheh, I just had a mean little idea.....


There's a bootleg Galaxian board in the machine right now.....guess which RAMs there are on it ....and I'm pretty sure they're OK since the game works (with graphics problems yes but that's character ROMs for sure) sooooooo....why not "borrow" them (at least for now)

[PaulSwan]

The 2101 any speed will do, but the 5101 IIRC are very very slow. Keep those 5101 handy for battery backed RAM games
There should be 5 heat sinks on the 5 attack rams in the corner.
You mean 74HCT259. The HCT means CMOS but with TTL levels. However, LS series should still be commonly available if you want to go with the original part.
I did do a run of DIY kits on the Arduino widget but I have none left now. I posted about it a while ago, this thing: http://www.paulswan.me/Arcade/ArduinoMegaICT.htm
Regards,
Paul.

[level42]

  Totally missed that, going to read that

I don't have any 5101's, they're on Jon's board remember

Yeah I know they're HCT but the part number on the chip says 74HC259

[level42]

You mean 74HCT259. The HCT means CMOS but with TTL levels.

In fact....this kept bugging me and to be honest....you're wrong, and I was misled by you  

From Wikipedia:


HC – High-speed CMOS, similar performance to LS, 12 ns. 2.0–6.0 V.
HCT – High speed, compatible logic levels to bipolar parts.

...


Many parts in the CMOS HC, AC, and FC families are also offered in "T" versions (HCT, ACT, and FCT) which have input thresholds that are compatible with both TTL and 3.3 V CMOS signals. The non-T parts have conventional CMOS input thresholds.
"

So, HC and HCT are different. Not much, but different.

In my own words:
HC= high speed CMOS, so faster then normal CMOS, but voltage levels still at CMOS levels
HCT = high speed CMOS , faster than normal CMOS _AND_ voltages at TTL level....in other words, they are drop-in replacements for LS.


On Jon's board there are HC's, not HCT. Again, I'm assuming these work.....

My local dealer has 74LS259 @ €1.50 each and 74HCT259 @ €1.00 each...


What I've always understood was that HCT can be used instead of TTL.


Interesting sidenote, the NXP datasheet talks about the 74HC259 and 74HCT259 in "one go".....the key difference they mention are clear:

Input levels:
- For 74HC259: CMOS level
- For 74HCT259: TTL level

http://www.nxp.com/documents/data_sheet/74HC_HCT259.pdf

Anyway.......I'm picking up a couple of 74HCT259's today