[BBC-Micro] Only one beep

info at sprow.co.uk info at sprow.co.uk
Fri Jun 26 19:52:46 BST 2009


> In article <4A44FFD0.4000008 at oview.co.uk>, Chris Long
> <chris at oview.co.uk> writes
>>
>>    Thanks for your suggestions.  I figured it must be very close to
>>    booting - do you know at what point in the boot sequence the second
>>    higher beep occurs?
>
> When the OS starts a language (Basic) I think.  It's the last thing it
> does in the boot sequence.

The low pitch "burr" is the unconfigured sound chip, ie. it'll make that
sound even if you unplug the 6502.
The OS silences this when the system 6522 is set up (since it hangs off
the slow bus side of the 6522).
The second "bip" sound is just a VDU 7 which is embedded in the string
reporting the RAM size ("16K<7>" or "32K<7>"), which is why there is no
"bip" on a soft break, because the RAM size is not printed.
Sprow.





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