VDU command crashes hard on VDU 23 & VDU 25

[ukscone]

1 parameter VDU functions such as CLS seem to be fine but errors in the VDU 23 & VDU 25 (think it's the ;'s) cause the Agon to freeze up such that a warm boot doesn't work and needs to be power cycled either by pulling the plug or pressing the reset button. Sometime it seems that correct VDU 23 & VDU 25 also freeze up too but can't confirm that 100% yet

[breakintoprogram]

No safeguards on badly formed VDU commands.
To replicate:

• Type VDU 23 or VDU 25 either in BASIC or MOS

[breakintoprogram]

OK, getting stuck waiting for a VDP protocol that may not come back

// Get the current screen dimensions from the VDU
//
void getModeInformation() {
	vpd_protocol_flags &= 0xEF;					// Clear the semaphore flag
	putch(23);
	putch(0);
	putch(VDP_mode);
	while((vpd_protocol_flags & 0x10) == 0);	// Wait until the semaphore has been set
}

It's the last while that's the problem. Need to put a timeout in there as a minimum, possibly a retrry.

[breakintoprogram]

Added timeout to MOS - just need to add timeouts to VDP now.

[breakintoprogram]

All possible interactive VDU statements in VDP now timeout if incomplete data is sent to them.