Umbrella is new replacement of original HAL10H8(PAL10H8) chip used in ZX Spectrum 128 and +2(grey). New is used chip GAL16V8 with unrainer effect and disable read port #7FFD. For this new GAL16V8 you must connect pin 11 of GAL with signal RFSH (pin 28 on Z80CPU). In other GAL/HAL/PAL versions pin 11 is not used).