vanaards@p4.cs.man.ac.uk (Steven van Aardt) (03/08/91)
PLEASE DON'T REPLY TO ME - I'M ONLY FORWARDING THIS MESSAGE
From R.Reeves@cs.ucl.ac.uk Fri Mar 8 11:12:36 1991
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To: vanaards <(Steven van Aardt) vanaards%t7@cs.man.ac.uk>
Subject: Crashing
Date: Fri, 08 Mar 91 11:13:48 +0000
From: Rick Reeves <R.Reeves@cs.ucl.ac.uk>
Status: R
I don't know whether this is related at all, but with my old BBC B (and
apparently all other BBC Bs), if you type "G.0:G.0:G.0: ..." until the
buffer fills up, and then press return (assuming you don't have a program
in memory) Then the computer crashes, and makes strange non-terminating
sounds and puts occasional characters onto the screen.
This might be linked to your problem, but I don't know. You might like to
send this tidbit to the bulletin board (I can't) just for the interest of
BBC B users.
Bye,
Rick Reeves
,----------------------------------------------------------------------------.
|Beeep. My brain is currently not available, so any opinions expressed herein|
|should not be attributed to myself or my organisation, only to the motor |
|neurons that are currently driving each of my digits to stike the keyboard. |
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- JANET E-mail : vanaards@uk.ac.man.cs.p4 (Steven van Aardt) --
-- Warning this user has been designated for termination on the 21.6.91 --
---------------------------------------------------------------------------kvj@rhi.hi.is (Kristjan Valur Jonsson) (03/14/91)
In <vanaards.668436483@p4.cs.man.ac.uk> vanaards@p4.cs.man.ac.uk (Steven van Aardt) writes: > PLEASE DON'T REPLY TO ME - I'M ONLY FORWARDING THIS MESSAGE >I don't know whether this is related at all, but with my old BBC B (and >apparently all other BBC Bs), if you type "G.0:G.0:G.0: ..." until the >buffer fills up, and then press return (assuming you don't have a program >in memory) Then the computer crashes, and makes strange non-terminating >sounds and puts occasional characters onto the screen. >This might be linked to your problem, but I don't know. You might like to >send this tidbit to the bulletin board (I can't) just for the interest of >BBC B users. This is an old brainteaser from the good old BBC days. Now, why should the micro do this? The reason is that when all the G.0: 's are expanded into GOTO0: 's, the input buffer overflows into other buffers down in the OS's workspace (below &E00), and mainly into the sound buffer. Kristjan
gpvos@cs.vu.nl (Gerben 'P' Vos) (03/15/91)
kvj@rhi.hi.is (Kristjan Valur Jonsson) writes: >The reason is that when all the G.0: 's are expanded into GOTO0: 's, the input >buffer overflows into other buffers down in the OS's workspace (below &E00), >and mainly into the sound buffer. No. The G. gets compressed to a single token, just like a GOTO would. The 0 expands, because line numbers after a GOTO (or RESTORE, or THEN <line>) are encoded, so BASIC doesn't have to parse the decimal number, which would be slow compared to just decoding the binary bytes. A line number is expanded to a token (&8D, from the top of my head) and three bytes (it could have been two, but that has some complications when one of them would be a CR or even an ELSE token). So "G.0:" expands from 4 bytes to 5, which causes the mentioned effects. - Gerben -- --- Gerben Vos - Aconet: BIGBEN!Gerben Vos - Internet: gpvos@cs.vu.nl <>< ---- The question if a computer can think is as interesting as the question if ----- a submarine can swim. -- E. Dijkstra