RIP to BT Garner of MindRec.com... BT passed away early 2023 from health problems. He was one of the top PCE homebrew developers and founder of the OG Turbo List, then PCECP.com. Condolences to family and friends.
IMG
IMG
Main Menu

naked Memory Base 128

Started by wilykat, 01/02/2016, 10:41 PM

Previous topic - Next topic

0 Members and 2 Guests are viewing this topic.

wilykat

Didn't find this in Google search and the forum search is a bit dumb so I couldn't tell if anyone ever posted this before.

IMG

Uses Oki 128KBx1 serial RAM chip, a .047F cap as backup for when you change the batteries, and a NEC chip 65015 which looks like a small FPGA to me if the datasheet is correct.

There's not much one can do to hack this but it is useful as a 64x memory backup if you used certain game like Private Eye Dol (yes, dol not doll) to swap the entire 2k bank between the host system and one of the 64 blocks.  Sorry but Tennokoe card's only good for 4 banks and it's a bitch to replace the tiny battery plus no backup so if you take the battery out, the save's toast.

This seems like a better choice for when you have lots of saves to preserve and Tennokoe is not enough.  Memory Base 128 and one suitable CD game costs about the same as 2 working Tennokoe cards.

Pokun

Quote from: wilykat on 01/02/2016, 10:41 PMThis seems like a better choice for when you have lots of saves to preserve and Tennokoe is not enough.  Memory Base 128 and one suitable CD game costs about the same as 2 working Tennokoe cards.
Yup it is. I've been using the clone Save-kun (was cheaper) for a while and it's great. Save-kun and MB128 are fully cross-compatible.

wilykat

Right now Save-kun seems to be going for same price as MB128.  I did find an interesting page about accessing the save: http://pcedev.blockos.org/viewtopic.php?f=5&t=98

So it'd be possible to cook up a simple HuC ROM that can be used on Everdrive that checks for MB128 or SK, and if it's present and the BRAM is also present, then start up utility to copy from one to another or swap.  If either the BRAM (ie PC Engine, Coregrafx, and TG-16 without memory add on or CD system, and the portables) or if the device is not plugged in the controller port, put up a screen stating it can't run.

I don't know what games beside Private Eye Dol has easy to use bank swapping utility. Maybe it'd be possible to rip the code just for that section, maybe clarify a few points with help or tip, and make it work stand alone ROM?  The ROM would allow memory swapping on Turbobooster Plus, Memory Booster, and Tennokoe2 so those systems won't need to depend on CD-ROM system.

That page posted a few pictures of naked SK:
IMG
IMG
Other than the name of the logic chip and the board layout, it's the same.

A Black Falcon

Emerald Dragon and Private eye dol both have a memory-backup function.  The odd part is, the two are entirely incompatible with eachother -- system memory backups you make in Emerald Dragon can't be copied to and from the system in Private eye dol, and vice versa.  You're pretty much stuck with one or the other...

Emerald Dragon - You hold a button (or is it a d-pad direction?) when starting the game to boot in to the MB129 menu.  The game doesn't support saving to the MB128 for some stupid reason, but you can copy memory blocks back and forth between the system and backups you make on the MB128.  You cannot see files saved directly to the MB128 here, or Private eye dol memory backups, only ED's memory backups.  In Private eye dol, you see the sizes of these files on the MB128, but not what's in them.  The size is the total of all files in that block.

Private eye dol - This has a more comprehensive save backup program accessible from the menu.  You can make memory backups as in ED, though they're incompatible of course, and also view files on the system and MB128, with file sizes visible.  Private eye dol memory backups are all the maximum size of 2048, so they don't change in size based on the size actually used, unlike Emerald Dragon.

I haven't used the Private eye dol memory manager recently, I think it can do a few more things but had some limitations as well.  Maybe I'll go back to it and check that out.


As for the MB128 itself, I find it useful to use batteries wit ha tester, so I can check them every once in a while.  That onboard capacitor will not hold a charge for long, so if the batteries run out you probably will have lost your saves before you notice.  A set of good batteries should last 6+ months, though, so they do last a while.  And it DOES hold saves while the system is on (I presume it gets power from the system), so you can remove the battery box without worry, though that capacitor will hold them for a little while while you switch out batteries of course.

Pokun

#4
So Emerald Dragon is incompatible? Then I guess I'll stick with Private Eye Dol. So Emerald Dragon doesn't pad the the free space to 2048 byte in its backups, maybe that's why they are incompatible.

Quote from: wilykat on 01/06/2016, 08:32 PMI did find an interesting page about accessing the save: http://pcedev.blockos.org/viewtopic.php?f=5&t=98

So it'd be possible to cook up a simple HuC ROM that can be used on Everdrive that checks for MB128 or SK, and if it's present and the BRAM is also present, then start up utility to copy from one to another or swap.  If either the BRAM (ie PC Engine, Coregrafx, and TG-16 without memory add on or CD system, and the portables) or if the device is not plugged in the controller port, put up a screen stating it can't run.
Yeah MooZ is reverse engineering it so we can program it. It would be cool if there was a program like BRAM Tool that could read and write to the MB128. Here is his documents so far:
https://gist.githubusercontent.com/BlockoS/ad7098771aea4970886b/raw/6f5a58fb7555115a19e6a66c222fc4f716feef87/mb128.txt