I have a GQ-4X programmer with a 12v/1.5ma external power supply. Has worked well when burning the game roms (27c040, 27c4001), but I want to update the sound roms for my Demolition Man (specifically the Williams_1994_Demolition_Man_Home_ROMs_H_6_Set_Sound_And_Game_Swear_ROMs set).

U6 and SU2 are both UV erasable 27c4001 chips. The other, original sound chips (SU3-SU9) in the game are 27c4000, without the UV window.

I get errors when trying to write the 27c4000 chips - fails immediately at X address. Trying to erase these initially gives a message that they can't, or don't need to be erased.

Does anyone have any guidance on this? Thanks in advance!

Post last edited 6 years ago: “corrected game rom chip as U6, not U2”

#2 6 years ago

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ForceFlow

Pinside Moderator

9y 238K 31,333 268 14

OP
Quoted from mack505:
The other, original sound chips (SU3-SU9) in the game are 27c4000, without the UV window.

Did you remove the paper labels to expose the windows?

#3 6 years ago

F X

Coyote

Pinside member

9y 107K 8,986

You cannot re-program 27C4000 - those are OTP, one-time-programming. You will need to buy new, empty chips.

It's very likely you don't even need to do that - updates never include those chips, they're ''fixed'', so to speak, though I'm not 100% about that DemoMan set.

#4 6 years ago

MAP

mack505

Pinside member

Lorton, VA

8y 47,300 162 15

Quoted from ForceFlow:
Did you remove the paper labels to expose the windows?

Yes, the 27c4000 do not have the UV window

#5 6 years ago

MAP

mack505

Pinside member

Lorton, VA

8y 47,300 162 15

Quoted from Coyote:
You cannot re-program 27C4000 - those are OTP, one-time-programming. You will need to buy new, empty chips.
It's very likely you don't even need to do that - updates never include those chips, they're ''fixed'', so to speak, though I'm not 100% about that DemoMan set.

Ah, ok, that would be great if that is the case. I will give that a shot.

#6 6 years ago

MAP

mack505

Pinside member

Lorton, VA

8y 47,300 162 15

Quoted from Coyote:
You cannot re-program 27C4000 - those are OTP, one-time-programming. You will need to buy new, empty chips.
It's very likely you don't even need to do that - updates never include those chips, they're ''fixed'', so to speak, though I'm not 100% about that DemoMan set.

If I do need to write new chips for SU3-SU9, what would be the recommended replacement for the 27C4000?

#7 6 years ago

F X

Coyote

Pinside member

9y 107K 8,986

OP
Quoted from mack505:
If I do need to write new chips for SU3-SU9, what would be the recommended replacement for the 27C4000?

Load up the given files in the ZIp file, and verify against what's on the chips already. If it matches, then no need to replace and reprogram them.

27C4001 can be used in 27C4000's place, no problem.

#8 6 years ago

MAP

mack505

Pinside member

Lorton, VA

8y 47,300 162 15

Quoted from Coyote:
Load up the given files in the ZIp file, and verify against what's on the chips already. If it matches, then no need to replace and reprogram them.
27C4001 can be used in 27C4000's place, no problem.

Awesome, thank you!

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