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 ## TODO
 
-- [ ] Notes on possible architecture extensions to add support for a 16-bit IP
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+- [ ] Notes on possible architecture extensions to add support for a 16-bit IP
+- [ ] add tape drive to mainframe
+
+- review 8080 style io ports
+    - works bc they have 2 operands per instruction, i think
+
+## Networking - first bits of research
+
+- [Bus network](https://en.m.wikipedia.org/wiki/Bus_network)
+- [Econet](https://en.m.wikipedia.org/wiki/Econet)
+- [Telnet](https://en.wikipedia.org/wiki/Telnet)
+- [Adding a serial port to my 6502 computer – Mike's Software Blog](https://mike42.me/blog/2021-07-adding-a-serial-port-to-my-6502-computer)
+
+- uxn networking — not helpful to me, i think
+    - https://github.com/klardotsh/uxnyap
+    - https://compudanzas.net/uxn_tutorial_day_7.html
+    - https://hacklab.nilfm.cc/xrxs/about/
+
+
+## 6502 vectors
+
+https://www.masswerk.at/6502/6502_instruction_set.html
+
+> System Vectors
+> 
+> $FFFA, $FFFB ... NMI (Non-Maskable Interrupt) vector, 16-bit (LB, HB)  
+> $FFFC, $FFFD ... RES (Reset) vector, 16-bit (LB, HB)  
+> $FFFE, $FFFF ... IRQ (Interrupt Request) vector, 16-bit (LB, HB)  
+
+## Docs leftovers: alternative table format for instructions
+
+| lo ↓ / hi → | 0 (G0, M0) |
+|-------------|------------|
+| **0**       | END        |
+| **1**       | NOP        |
+| **2**       |            |
+| **3**       |            |
+| **4**       |            |
+| **5**       |            |
+| **6**       |            |
+| **7**       |            |
+|             |            |
+| **8**       |            |
+| **9**       |            |
+| **A**       |            |
+| **B**       |            |
+| **C**       |            |
+| **D**       |            |
+| **E**       |            |
+| **F**       |            |
+
+| lo ↓ / hi → | 5 (G1, M1) | 6 (G1, M2) |
+|-------------|------------|------------|
+| **0**       | LDA #      | LDA ind    |
+| **1**       | STO #      | STO ind    |
+| **2**       | ADD #      | ADD ind    |
+| **3**       | SUB #      | SUB ind    |
+| **4**       | JMP #      | JMP ind    |
+| **5**       | JEQ #      | JEQ ind    |
+| **6**       | JFL #      | JFL ind    |
+| **7**       | FTG #      | FTG ind    |
+|             |            |            |
+| **8**       | MUL #      | MUL ind    |
+| **9**       | DIV #      | DIV ind    |
+| **A**       | JLT #      | JLT #      |
+| **B**       | JGT #      | JGT #      |
+| **C**       | NOT #      | NOT #      |
+| **D**       | AND #      | AND #      |
+| **E**       | OR  #      | OR  #      |
+| **F**       | XOR #      | XOR #      |
+
+| lo ↓ / hi → | 9 (G2, M1) | A (G2, M2) |
+|-------------|------------|------------|
+| **0**       | DEV #      | DEV ind    |
+| **1**       | INP #      | INP ind    |
+| **2**       | OUT #      | OUT ind    |
+| **3**       | FED        | FED        |
+| **4**       |            |            |
+| **5**       |            |            |
+| **6**       |            |            |
+| **7**       |            |            |
+|             |            |            |
+| **8**       |            |            |
+| **9**       |            |            |
+| **A**       |            |            |
+| **B**       |            |            |
+| **C**       |            |            |
+| **D**       |            |            |
+| **E**       |            |            |
+| **F**       |            |            |
+
+| lo ↓ / hi → | F (G3, M3) |
+|-------------|------------|
+| **0**       |            |
+| **1**       |            |
+| **2**       |            |
+| **3**       |            |
+| **4**       |            |
+| **5**       |            |
+| **6**       |            |
+| **7**       |            |
+|             |            |
+| **8**       | RSL A      |
+| **9**       | RSR A      |
+| **A**       | ASL A      |
+| **B**       | ASR A      |
+| **C**       |            |
+| **D**       |            |
+| **E**       |            |
+| **F**       |            |
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