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→Week 4
=== Week 4 - Class II ===
* Strings and System Routines
** Using The [6502 Emulator|emulator] has a Character Display80x25 character display mapped starting at location '''$f000'''. Writing to a byte to screen memory will cause that character to be displayed at the corresponding location on the screen, if the character is printable. If the high bit is set, the character will be displayed in <span style="background:black;colour:white;"> reverse video </span>.** A "ROM chip" is mapped into the emulator at the end of the memory space (at the time of writing, the current version of the ROM exists in pages $fe and $ff). Details of the available ROM routines can be viewed using the "Notes" button in the emulator or on the [[6502_Emulator#ROM_Routines|emulator page]] on this wiki.** Strings in assembler are stored as sequences of bytes. As always, memory management is left to the programmer. You can terminate strings with null bytes (C-style), which are easy to detect one some CPUs (e.g., <code>lda</code> followed by <code>bne / beq</code> on a 6502), or you can use character counts to track string lengths.
* Building Code
=== Week 4 Deliverables ===
* Blog your [[6502 Assembly Language Math Lab|Lab 3]] results.
* Blogs are due at the end of the month (Feb 2 - 11:59 pm), so proofread your posts, ensure that you have at least 1-2 per week, and make sure the link from the [[Winter 2020 SPO600 Participants|Participant's Page]] is accurate.
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