AnachronautandClaude Opus 5
5fd995aa62
A breakpoint that shows every register as the program had them, waits for a key, and carries on. NOTHING IS OVERWRITTEN, and that is the design rather than a shortcut. A breakpoint poked into a running program has to replace an instruction, and putting that instruction back in order to continue is the same act as disarming the breakpoint; firing a second time would mean stepping over the restored instruction and putting the breakpoint back behind it, and this machine cannot step a single instruction. SWI is two bytes, dispatches through a vector, and its frame already holds the address after it, so RETI resumes at the next instruction with nothing to restore and nothing to re-arm. It fires every time it is reached. The price is that a breakpoint is part of the program: a build with them in has different addresses from a build without. That is the bargain every machine with a break instruction makes. Every value shown comes out of the frame rather than the registers, because by the time the handler runs the registers are the handler's. Apps/Break.asm stops twice so that the second stop is checked as well as the first. Also here, found by the test that came with it: the monitor's s wrote into whichever bank was selected, and bank 2 is the controller's own table, published read only. Writing to it was refused, and a refusal nobody catches stops the machine - so selecting the bank table to look at it and then typing s killed the session. bankPresent now keeps the whole flags byte and s declines. The recorded output of cosmosMonitor had contained that crash, having been blessed without being read. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
17 lines
320 B
Plaintext
17 lines
320 B
Plaintext
CosmOS
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> loaded, starting at 2000
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> two stops, and what the registers were at each
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break at 200E
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A 11 B 22 Q 00 S 00
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DP0 1030 DP1 05CC DP2 039A DP3 2000
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press a key
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break at 2018
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A 44 B 55 Q 00 S 00
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DP0 1000 DP1 05CC DP2 039A DP3 2000
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press a key
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carried on to the end
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finished
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> halted
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Execution halted.
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[exit 0]
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