* '''Board: 2700-017P-3, MC0123B, Copyright 1990, K1'''
* R153 installed (near SCART connector)
* handmade NR2 (between CPU and PSG)
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* '''Board: 2700-017P-4, MC0123C, Copyright 1990, K1''' ([[Media:Terje GX4000-MC0123C-K1 unrotated.jpg|other picture]])
* R153 not installed (near SCART connector)
* R135D135-R142 D142 instead of NR2, R1/R2/C2 rearranged (between CPU and PSG)* bigger R181(3 Watts), D180/R181 rearranged (near RGB monitor connector)
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