Two questions in two days! Sorry to be a pest
There are plenty of variations of the following code kicking around on the Internet which is described as performing a toggle function on a single bit of a specifiv byte in the CMOS to toggle the VIDC POST checks on and off.
Code:
REM Toggle state of power on self test bit in CMOS
REM Read byte
SYS "OS_Byte",161,&BC TO ,,byte%
REM EOR byte with mask for bit 1
byte% = byte% EOR 1<<7
REM Write byte back again
SYS "OS_Byte",162,&BC,byte%
END
REM Read byte
SYS "OS_Byte",161,&BC TO ,,byte%
REM EOR byte with mask for bit 1
byte% = byte% EOR 1<<7
REM Write byte back again
SYS "OS_Byte",162,&BC,byte%
END
The thing is, on my machine at least, it doesn't appear to work.
That is to say, it clearly toggles the relevant bit in the relevant byte in the CMOS and that value is carried over between power cycles. It doesn't however have any effect on whether or not the VIDC POST check is run. On the machine I've tested it on with RO3.11, the VIDC POST is always run regardless of the setting of the bit.
Does anyone know which versions of RISC OS this is meant to work with? Clearly as the POST was introduced with RISC OS 3.00 and the code being described as working with RISC OS 3, I thought it reasonable to assume that it would simply work on my machine. Sadly, that's not the case...
Paul