robhagemans
Calculating PI with Nilakantha formula. *Bug*
A blue screen occur with the attachment sent.
I can confirm this issue.
The error is dereferencing a string at address &H1697 which isn't there anymore. That address is very close to the end of the program (&H1653) and there is a string at &HFDCB that's not bound to a variable name, so I guess what happened was that string is the first argument of MID$(), then the creation of the string involved in the third arguments expression triggered a garbage collection that moved the string data of the first argument from &H1697 to &HFDCB but the code still tries to access it at the old address.
That seems to be a bug in PC-BASIC because the programs runs without those problems in GW-BASIC.
Thank you! Happy to help and test.
Ron.
From: Marc Rintsch @.> Sent: Saturday, July 19, 2025 8:27 AM To: robhagemans/pcbasic @.> Cc: Ronald-Herrera @.>; Author @.> Subject: Re: [robhagemans/pcbasic] Calculating PI with Nilakantha formula. Bug (Issue #251)
[https://avatars.githubusercontent.com/u/2564163?s=20&v=4]Marrin left a comment (robhagemans/pcbasic#251)https://github.com/robhagemans/pcbasic/issues/251#issuecomment-3092325134
I can confirm this issue.
The error is dereferencing a string at address &H1697 which isn't there anymore. That address is very close to the end of the program (&H1653) and there is a string at &HFDCB that's not bound to a variable name, so I guess what happened was that string is the first argument of MID$(), then the creation of the string involved in the third arguments expression triggered a garbage collection that moved the string data of the first argument from &H1697 to &HFDCB but the code still tries to access it at the old address.
That seems to be a bug in PC-BASIC because the programs runs without those problems in GW-BASIC.
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