DOS: a single call to INPUT causes a GPF with CWSDPMI

```
dim i as string
input "?", i
end
```
That's all you need to reproduce this issue. Extraordinarily catastrophic failure. Happens with an old version of CWSDPMI I had, and the new r7. Happens with every version of FB I have including 1.20 beta.

Does not happen with HDPMI32.