Panasonic A1WX - Looking for info

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Par Pentarou

Champion (506)

Portrait de Pentarou

25-11-2008, 00:32

Hello,
Are there schematics that can be downloaded for the A1WX or A1WSX?

By looking at the circuit board I've found a lot of things I'm curious about, having a schematic could provide a few answers...
For example:

In the lower right there are 3 places where ICS can be placed, what were those ICs supposed to do?

What about the empty ROM space (IC15)? Can it be used for something useful? It's marked as "ROM 1M/512K" so 1Mbit, how would that be mapped?

There are 3 ROM ICs for a total of 12Mbit! How are those used and how are they mapped in memory?

Question

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Par LeoM

Master (229)

Portrait de LeoM

25-11-2008, 12:38

Maybe this will help??

Par Pentarou

Champion (506)

Portrait de Pentarou

25-11-2008, 18:59

Not quite Sad
Memory expansion is NOT the info I was looking for Crying

Par dhau

Paragon (1570)

Portrait de dhau

25-11-2008, 23:20

I only have WSX, but I suspect that FX, WX and WSX all share the same or very similar board layout. Ultimate MSX FAQ says WSX has more rom firmware then WX, and FX has less. So may be comparing boards could kind of give you the idea of what was in the missing chip. Mind you, if I remember right, even on WSX there are lots of free places for ROM chips, so who knows.

Par Pentarou

Champion (506)

Portrait de Pentarou

26-11-2008, 00:27

WSX and WX pcbs look almost the same, both have empty IC places and (AFAIK) they don't differ in firmware.
Maybe I could find out how the ROMs are mapped by looking at a configuration file from an emulator...
Still it would be nice to find a schematic Crying

Par dhau

Paragon (1570)

Portrait de dhau

28-11-2008, 19:07

I opened up my WSX. It has a 512Kbit masked rom chip soldered in IC15. So WSX has 64Kbytes of firmware more then WX.

WX roms for OpenMSX (fs-a1wx.zip) are probably just a copy of WSX dumps.

Pentarou, please make a photo of your motherboard, or at least post the PCB model number.

I just bought a broken MSX computer, which I suspect is a WX with WSX top cover, since it doesn't have S-Video out, but does have Tape I/O port. The PCB model number is DFUP0250ZAU1a (c) 1988 Matsushita. This computer have YM2413 chip (IC5) and two chips marked 8464A-15L (IC19 and IC20), so it's not FX. It doesn't have IC15 soldered in.

Par dhau

Paragon (1570)

Portrait de dhau

28-11-2008, 19:29

I made a photo of the suspected WX motherboard: tht.net/~aoboroc/

Par Pentarou

Champion (506)

Portrait de Pentarou

28-11-2008, 20:08

Motherboard is DFUP0250ZAUa and here's the pic: http://img142.imageshack.us/img142/3244/wsxqh2.jpg
As you can see there are some differences, mainly the TC40H004 chip at IC9, but besides that I would say the 2 boards are the same.

I opened up my WSX. It has a 512Kbit masked rom chip soldered in IC15. So WSX has 64Kbytes of firmware more then WX.
Strange, I've seen photos of WSX PCB (from the memory expansion tutorials) and IC15 is empty :-?
Can you post a pic of your WSX board?

Par Manuel

Ascended (19273)

Portrait de Manuel

28-11-2008, 20:41

WX roms for OpenMSX (fs-a1wx.zip) are probably just a copy of WSX dumps.

Of course they are NOT! They are dumped by owners of the machine and verified from the dumps originally made by Atarulum.

You offend me by making such remarks Sad

Par Jipe

Paragon (1594)

Portrait de Jipe

28-11-2008, 22:14

the chips 8464 are different package but is S-RAM 8k
other different are RAM 64k and 256k

Par Pentarou

Champion (506)

Portrait de Pentarou

28-11-2008, 22:32

the chips 8464 are different package but is S-RAM 8k
Yes, I know that, and the DRAM was originally 64Kb chips Wink

I've downloaded the fsa1wx.zip file and the "a1wxfira.rom" is 16 Mbit! (although there seem to be a 25% overdump at the end) is that the correct ROM image?

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