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+# Dev notes — 2023-08-15
+
+## Goals for today
+
+- [x] Review planned changes to simulator
+  - [x] 'opcodes' and 'operands'
+  - [x] fix $00 contains $20 bug
+
+- [ ] Review planned changes to the system
+  - [x] CHP, CFC -> FHP, FTG -- dev note 2023-08-07
+  - [ ] ? 5x5 display
+  - [ ] bank-switching flag in 0 page
+
+- [ ] Implement any changes necessary for writing a program?
+- [ ] Write a program
+  - [ ] LOGO turtle on 5x5?
+
+## Overflow flag
+
+Ken Shirriff, [The 6502 overflow flag explained mathematically](https://www.righto.com/2012/12/the-6502-overflow-flag-explained.html):
+
+> A common definition of overflow is `V = C6 xor C7`. That is, overflow happens if the carry into bit 7 is different from the carry out.
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