I misunderstood the meaning of D2 on entry to the trap:
- If 1, preserve window contents;
- If zero, don't preserve.
I thought this meant CLS if zero! Silly me. However, in testing with non-zero values, I always get an "invalid parameter" error, only zero seems to work. For what it's worth, the code is running in a job, not as a CALLed routine or a S*BASIC extension.
I think it's D2, I'm typing this in the bath, but it's the register which does or doesn't preserve the contents.
Is this a known bug? Am I doing something wrong -- again! Am I talking bollox -- again.
This is using QPC2_5.02 (but not today's patched version), on Linux, under Wine. SMSQ/E is 3.38 as supplied with QPC.