STM locked in 60 Hz PAL mode problem

[microman]

I have an old STM ( C070243 Rev H) that I have just upgraded to TOS 1.04 UK 6 x 27C256
roms.

However, when I try to switch the Video between 50 & 60 Hz it appears to be locked in 60 Hz PAL mode - a valid PAL mode but not in the UK.

I am trying to use the 'V' option in SYSINFO to change standards but both my Scan converter and SYSINFO show only 60 Hz PAL available.

Not sure if it had this issue before the TOS upgrade. Other than that it seems to be working fine.

The scan converter is happy with either input - My RM kit is PAL 50 Hz.


Any suggestions?

Thanks

Peter

[exxos]

Maybe check what oscillator it has in there ?

Capture.JPG (62.76 KiB) Viewed 1776 times

I am assume NTSC goes with 60hz, but don't remember off-hand.

[microman]

Thanks for the input. I have now discovered that my problem would appear to be due to the Diagnostics cartridge that I have. It would appear to initialize this mode. Now that I have 4 Mb RAM it would appear to allow switching into 50Hz PAL mode but always seems to start up in 60Hz PAL mode.

Peter