Anachronaut
87d819847e
SWI osExit takes a status in A, and the shell keeps it. Fifty eight exits across twenty three programs now say deliberately whether they worked: 25 did what they were asked, 24 did not, 9 were asked wrongly. Compare is the exception and says so - one there means the files differ, which is a result rather than a failure, the way diff has always had it. IN A RATHER THAN Q, which is not a departure from the rule that a service answers in Q. This one takes an ARGUMENT, the way osPrintNumber takes A and B, and it never returns to answer anything. A is free precisely because a return would have put it back - and Q is the ALU's output, so a small number costs four instructions there against one in A. The shell does not print it. A program that failed has already said so in words and a number beside that is noise, so osLastStatus hands it back and Status is the program that shows it. That indirection is the point: the number exists for the thing that cannot read words. MARKING THE EXITS FOUND A DEFECT ON THE FIRST RUN. Type and More printed why they had failed and then fell through into the success exit, reporting that all was well. Nobody had noticed, because while the only reader was a person, the person could see both the complaint and the claim. Two smaller things. Snake sets the console to line mode and then exits with zero, and the linter flagged the second RSTA as redundant - an exit status and a console mode, equal by accident, which is the class that must never be collapsed. And the README still taught answering by writing into the frame, three months of habit that SRET replaced yesterday; that section is gone and the one describing SRET stands in its place.
32 lines
1.1 KiB
NASM
32 lines
1.1 KiB
NASM
; This is a basic hello world program for the SplitBit CPU.
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; We'll create a loop that outputs each byte of our string to Output 0, the text console.
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; Include the system services so we can return.
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#Include services.asm
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#Program
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#Base 0x4000 ; Change two:
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SETD hello ; Change three
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Start:
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LDA ; Load a byte of the string into A.
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BRA End ; If A is zero, branch out of the loop.
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OUTA 0x00 ; Output the value in A to Port 0, the text console.
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INCD ; Increment the Data Pointer to the next byte of the string.
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BRI Start ; Branch immediately to the start of the loop.
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End:
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INIA 0x0A ; We'll load a linefeed into A and output it to make it look nice.
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OUTA 0x00 ; Output it to the text console.
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;HALT ; Terminate the program.
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; Instead, let's call osExit to return the system nicely. Fourth change.
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RSTA
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SWI osExit
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#Data
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#Base 0x2000 ; Five, adjust the base of the data segment.
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hello: ; Throw a label here so we can explicitly point at this data. Six, actually.
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"Hello, World!"
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