Yamaha AX350(II) possible ram upgrade?

Resident (62)

05-09-2015, 23:15

Is this four free chip slots for adding more ram?

The chips around the free chip slots are Sharp LH2464-12, which are 32kb ram chips.

Could I solder on more ram in these free slots? The ram type is still available locally, so it would be really neat for me.

Here are the specs for the LH2464-12: http://www.datasheets360.com/part/detail/lh2464-12/-38641981...

High resolution pictures here on this album on imgur, also showing full motherboard front and back: http://imgur.com/a/mzEpK

Aangemeld of registreer om reacties te plaatsen

Van mister.phr0zen

Expert (103)

05-09-2015, 23:29

These are all for RAM, not VRAM.

The VRAM is near the VDP, as you can see here:

Van msxski

Resident (62)

05-09-2015, 23:36

Thanks!

Van msxski

Resident (62)

08-09-2015, 17:46

No one knows? I'm tempted to solder in chips and see what happens.

Van mars2000you

Enlighted (6402)

08-09-2015, 18:22

Probably more RAM can be added. The "ultimate" Al Alamiah, the until now not dumped AX-500 has 256 Kb RAM.

You can find the service manual on the Hans Otten website : http://msx.hansotten.com/uploads/msxdocs/ax500servicemanual.pdf

Van Jipe

Paragon (1586)

08-09-2015, 18:33

the LH2464-12 are 64K x 4 bits
2 X memory make 64K x 8 bits
with 4 memory you have 128K X 8 bits
the 74LS670 can adress 256K
i think you can added 4 X LH2464-12 for obtain a total of 256K

Van msxski

Resident (62)

11-09-2015, 18:03

Ram ordered. Easier than desoldering from donor boards. Wish me luck.

Van mister.phr0zen

Expert (103)

11-09-2015, 18:18

As we can see in this picture, you can safely add the RAM ICs and double the memory on your MSX

let us know, good luck!

Van Jipe

Paragon (1586)

11-09-2015, 18:19

use DIL IC-Socket Tulip for best

Van msxski

Resident (62)

11-09-2015, 23:41

THNX Phrozen!

Van mister.phr0zen

Expert (103)

13-09-2015, 18:00

If you have good soldering skills you can easily do a 512KB mapper upgrade, like this one (in Sony HB-F1 XV) :
Tabajara labs Sony HB-F1 XV 512KB mapper upgrade

If needed, I can help in translating to English some parts of the tutorial.