Help with replacing the secondary rom with a reprogrammed one on MSX-1

Door bazabaza

Expert (70)

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30-04-2015, 04:04

I bought an MSX-1 but seems the secondary bios (where MSX animation is stored) has a bug. and I was wondering what it entails to replace it with a one I reprogram. can anyone please guide me to the right way to do that?

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Van bazabaza

Expert (70)

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30-04-2015, 05:49

What I understood so far, it seems it is an eprom. but not sure which one. though I suspect one of them with IC8 written under it and it has exposed UV window. maybe the bug is due to accidental erasing or damage?
This one is
B8752
nmc27c256q 250

Is replacing it with a reprogrammed nmc27c256q 20 would work? what's the 250 or 20 means?

Van Manuel

Ascended (18958)

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30-04-2015, 07:32

There is no real animation on MSX1... Just two lines of text

Van bazabaza

Expert (70)

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30-04-2015, 07:39

This is a localized version. It is Arabic version called (Perfect) made by Daewoo. it has a long animation.

Van mohai

Paladin (978)

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30-04-2015, 09:54

Any EPROM (or flash) chip such as 27256, 27c256 or so will be OK for replacement.
You will have to get proper ROM file for your MSX, burn it and replace.

20, 250, 150, 15 .... means chip speed.
200 or 20 = 200 milisec // 15 or 150 = 150 milisec

For an MSX-1 speed is not critical, but try not to use any slower chip.

B8752 is manufacrure year and week.

Van bazabaza

Expert (70)

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30-04-2015, 10:17

Thanks, I will try to do that. I found a cheap service here to write eprom Big smile . hope it works well.