Hello, for now i could made some updates to the HB-F5, roms to MSX2+, VDP to V9958, Z80 CPU 8Mhz, redirect internal RAM from SLOT 0-X to SLOT 3-X, also planning to install 512K SRAM external memory mapper LPE-512KBSRAM-V3 into MSX like expanded to future free use of SLOT1&SLOT2, L.Padial told me that this SRAM memory mapper supports 8Mhz OK or more; but first i´ll prefer to install the MSX SUPER TURBO because once placed the memory mapper into the MSX probably could hinder the location and installation of MSX SUPER TURBO. Ok, based on the installation made in the HB-F9S I have begun to locate points on the hb-f5 possibly related to the MSX SUPER TURBO installation, the HB-F5 has no service manual, i had to make this searching testing point by point into HB-F5 motherboard, for now i get this info:

Regards.
Thanks a lot for help.

FWIW: with no schematic and no way to check the machine myself, I don't think I'll help you here - good luck...
Why exactly would you want to expand a rare/collector machine like this with everything & the kitchen sink, again?
