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Fixed formatting around memory locations #2

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Fixed formatting around memory locations #2

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36 changes: 19 additions & 17 deletions README.md
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Expand Up @@ -78,26 +78,28 @@ If your're connected to the emulated system the following commands can be used:

## 5.0 Memory Map

0x0000 - 0x00ff Zeropage
0x0100 - 0x01ff Stack
0x0200 - 0x03ff input buffer used only by VTL2
0x0400 start of program memroy for VTL2
0x0200 - 0x7ffb free memory (upper limit depends on Arduino RAM settings)
0x7ffc - 0x7ffd 16 bit address used as NMI vector from MIOS kernel (writeable)
0x7ffe - 0x7fff 16 bit address used as IRQ vector from MIOS kernel (writeable)
0xe000 - 0xffff ROM
| Range | Description |
| - | - |
| 0x0000 - 0x00ff | Zeropage
| 0x0100 - 0x01ff | Stack
| 0x0200 - 0x03ff | input buffer used only by VTL2
| 0x0400 | start of program memory for VTL2
| 0x0200 - 0x7ffb | free memory (upper limit depends on Arduino RAM settings)
| 0x7ffc - 0x7ffd | 16 bit address used as NMI vector from MIOS kernel (writeable)
| 0x7ffe - 0x7fff | 16 bit address used as IRQ vector from MIOS kernel (writeable)
| 0xe000 - 0xffff | ROM

## 6.0 Special Addresses

0x7ffc - 0x7ffd 16 bit address used as NMI vector from MIOS kernel (writeable)
0x7ffe - 0x7fff 16 bit address used as IRQ vector from MIOS kernel (writeable)

0xfff8 fake ACIA input register
0xfff9 fake ACIA output register

0xfffa - 0xfffb 6502 NMI vector
0xfffc - 0xfffd 6502 RESET vector
0xfffe - 0xffff 6502 IRQ vector
| Address | Description |
| - | - |
| 0x7ffc - 0x7ffd | 16 bit address used as NMI vector from MIOS kernel (writeable) |
| 0x7ffe - 0x7fff | 16 bit address used as IRQ vector from MIOS kernel (writeable) |
| 0xfff8 | fake ACIA input register |
| 0xfff9 | fake ACIA output register |
| 0xfffa - 0xfffb | 6502 NMI vector |
| 0xfffc - 0xfffd | 6502 RESET vector |
| 0xfffe - 0xffff | 6502 IRQ vector |

## 7.0 Using interrupts

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