I think you need to start confirming that your memory systems are working. For the ram modules and main rom, check at the pins
All address lines can be observed to toggle All data lines similarly toggle Chip select lines toggle I've had 2 t200 with broken traces in the past. Ram is provided by that separate board which is connected via a cable. Worth a close look. Good luck Steve On Sunday, February 20, 2022, Gsvacances Free <[email protected]> wrote: > Hi everyone, > > Here is an update of the checking I've today. > > The LCDC HD61030 is held unselected since its /CS pin (labeled /LCD on the > schematics) is high all the time. > I guess that's why the LCD is black all the time. > > If I've read well the schematics, this signal /LCD comes from the > SLA5080FOU gate array and is the logic result > of the combination of signals ALE, /RESET and IO/M and AD04-AD7. > > On the CPU, there is a brief activity on AD6 and AD7 and then, they stay > high all the time. > > As for IO/M pin on the CPU, it is high when reset is active but then seems > to stay low all the time afterward. > > So, it seems the CPU never tries to access I/O and thus /LCD signal cannot > go low and activate the LCDC chip. > > Just to be sure, can someone confirm the chips on sockets M13, M14 and M15 > please ? > > Here's what I have: > > - M13 = 364E43-6A3 also written 10002 > - M14 = 3256S27-6H1 also written 10003 > - M15 = 3256S97-6H3 also written 10001 > > All 3 chips have "MICROSOFT" written on them. > > > Thanks in advance for your help ! > > > > Gilles >
