Games with problems

feedback, questions and discussion relating to www.bbcmicro.co.uk
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sweh
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Re: Games with problems

Post by sweh » Thu May 07, 2020 1:10 am

vanekp wrote:
Wed May 06, 2020 8:45 pm
160*LOAD HELL1
170*TAPE
180CALL&4A72
which probably then makes the BASIC ROM the default ROM fixing the problem mentioned by Sarah.
You probably don't need *TAPE because BASIC will already be paged back in to run the CALL command. Unless the program makes a filesystem call before reading &8000...

A simple test:

Code: Select all

   10FOR A=0 TO 2 STEP 2
   20P%=&2000
   30[OPT A
   40LDX #0
   50.LP
   60LDA &8000,X
   70STA &3000,X
   80INX
   90BNE LP
  100LDA &F4
  110STA &3100
  120RTS
  130]
  140NEXT
  150*SAVE BAR 2000+100
If you "*RUN BAR" then it will put the DFS ROM contents into &3000. But if you "*LOAD BAR" then "CALL &2000" then the BASIC ROM contents are at &3000.

Funky!
Rgds
Stephen

Michael Brown
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Re: Games with problems

Post by Michael Brown » Thu May 07, 2020 8:41 am

Hi All,

The main reason why I did not add *TAPE originally is because there is a machine code LDA#&8C at &4A26 in HELL1.
So would simply...
160 *LOAD HELL1
170 call&4A72
...do the job?

regards,
Mick.

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vanekp
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Re: Games with problems

Post by vanekp » Thu May 07, 2020 11:00 am

oh there is I did not see that when I looked in the code, so I must have missed that but yes then the *TAPE is not required.
it also will do no harm but just be careful as there is code sitting above the basic program hell-ho.
Peter.

Michael Brown
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Re: Games with problems

Post by Michael Brown » Thu May 07, 2020 2:06 pm

Now amended the copy on my D041.
Thanks
Mick.

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