Changing a PAC battery

Paladin (931)

27-10-2015, 06:04

Hey guys, real quick question:

I've previously had the battery inside a copy of Xanadu (MSX1 version) changed at a local mom-and-pop game shop near me, which wound up being a super-simple task -- the type of battery used was really easy to find and really cheap, and even with them changing it for me in the store, it only cost me a total of $8 for the battery and the labor, and it worked perfectly afterward.

I recently got myself a Pana Amusement Cartridge, though, and I just wanted to check and see if it's more or less the same thing. If I took it to the same mom-and-pop shop, would they be able to just swap out the battery with a new one like they did for me with Xanadu, or does the PAC have more complex hardware to deal with, use a less common battery, etc.?

I'm assuming it'll be essentially the same thing, since both Xanadu and the PAC seem to just use a standard cartridge battery to preserve SRAM data, but I wanted to be absolutely certain before taking it in.

Thanks for any help you can provide!

-Tom

By wyrdwad

Paladin (931)

27-10-2015, 07:18

Hmmm... and while I'm at it, how would I test a PAC to make sure it even works at all? I tried saving my Fire Hawk game with the PAC inserted and it didn't seem to work, but I'm not sure if that's because the save was being written to the PAC but the PAC has a dead battery, or the PAC wasn't recognized and the save was being written to the clock chip (which wouldn't save permanently either, since I don't have any batteries inserted into my MSX). Is there any way to tell, aside from just changing the battery in the PAC and... hoping it works?

-Tom

By o.geerdink

Hero (585)

27-10-2015, 10:56

Firehawk stores the gamedata in the clockchip of your MSX. If your msx has no battery it will not hold the data.

By NYYRIKKI

Enlighted (5923)

27-10-2015, 11:57

You can tell that Firehawk has detected PAC when you have 9 save slots available instead just one. IIRC there was a bug that caused FM-PAC not to be detected on certain subslots. If I'm correct there is also SRAM backup/restore functionality inside the internal software of FM-PAC.

By Manuel

Ascended (18794)

27-10-2015, 23:17

But he has a PAC and not an FM-PAC... so that doesn't help...

By wyrdwad

Paladin (931)

28-10-2015, 04:06

If Fire Hawk shows 9 slots for even a regular PAC, though, then that's as good a way as any to tell if the PAC is being detected. Clearly, it was not when I tried it yesterday -- even after cleaning the connectors (which were legitimately pretty dirty) -- but I'll try again today. I might give it a second cleaning, and also try it in the second cartridge slot (which I don't use very often because the plastic around it is broken and warped, making most cartridges a really snug fit -- this MSX2+ works great, but it's clear it took quite a beating at some point in its life, as the chassy has most definitely seen better days).

It could also simply be that the battery inside the PAC is dead, which wouldn't be too surprising for a nearly 30-year-old cartridge. So I'll probably get the battery swapped out this weekend and see if that does the trick -- assuming it is indeed as simple a task to swap out the battery in this thing as it was in Xanadu, anyway.

-Tom

By wyrdwad

Paladin (931)

28-10-2015, 09:15

Man... I do feel like an idiot now.

I finagled the PAC into my second cartridge slot, and it's now working like a charm. It... kind of stands to reason that the thing is probably meant to be plugged into the off-slot rather than the main slot, since it's designed to work with cartridge games and disk games alike -- I just never really thought of that previously, and was only bothering to test it in my main cartridge slot.

So I've now at least confirmed that the thing is fully functional! The question is, if I wanted to replace the internal battery as a precaution, would it be a simple task, or would it be more complex than I'm anticipating?

(Thanks, BTW, to all of you who've responded thus far! Sorry to be such a dimwit about this. Heh.)

-Tom

By NYYRIKKI

Enlighted (5923)

28-10-2015, 09:38

Ok, at this point I would dig up some proper tools to investigate the problem...

Here is one way how you can test this:

- Download my favorite übertool Super-X
- Plug PAC in slot 1
- Type following:
BLOAD"SUPER-X.LDR",R
_@
M5FFE#1
:694D
(Press CTRL+STOP)
D4000

... you have now HEX-dump of the SRAM memory content on your screen. Try writing something by using number keys and see if the memory on screen changes.

By NYYRIKKI

Enlighted (5923)

28-10-2015, 09:39

Oh, you got it working already... nice to hear. Sorry, I have no idea about PAC battery.

By Jipe

Paragon (1551)

28-10-2015, 11:18

in the PAC the battery is a Matsushita BR2325 3V
same : http://www.alliedelec.com/images/products/Small/70196842.jpg

By o.geerdink

Hero (585)

28-10-2015, 15:04

I don't think the slot should matter.