Editing Amiga 500 (section)

=== Memory ===
Using various expansion techniques, the A500's total RAM can reach up to 138&nbsp;MB – 2&nbsp;MB Chip RAM, 8&nbsp;MB 16-bit Fast RAM, and 128&nbsp;MB 32-bit Fast RAM.{{efn|name=binpre}}

==== Chip RAM ====
The stock 512&nbsp;KB Chip RAM can be complemented by 512&nbsp;KB using a "trapdoor" expansion (Commodore A501 or compatible).{{efn|name=binpre}} While that expansion memory is connected to the chip bus, hardware limitations of early stock Agnus chip revisions prevent its use as Chip RAM, only the CPU can access it. Suffering from the same contention limitations as Chip RAM, that memory is known as "Slow RAM" or "Pseudo-fast RAM". Agnus revisions shipped with late A500 are [[Amiga Enhanced Chip Set|ECS]] and allow use of trapdoor RAM as real Chip RAM for a total 1&nbsp;MB.{{efn|name=binpre}} 

Additionally, several third-party expansions exist with up to 2&nbsp;MB{{efn|name=binpre}} on the trapdoor board. Using a [[Amiga custom chips#Gary|Gary]] adapter, that memory will be mapped as either split on Chip RAM and Slow RAM or fully as Slow RAM, depending on configuration.

Furthermore, using an [[Amiga 3000|A3000]] Agnus on an adapter board, it is possible to expand the Chip RAM to 2&nbsp;MB, matching the A500+.{{efn|name=binpre}}

==== Fast RAM ====
"Fast" RAM is located on the CPU-side bus. Its access is exclusive to the CPU and not slowed by any chipset access. The side expansion port allows for up to 8&nbsp;MB{{efn|name=binpre}} of [[Zorro II|Zorro-style]] expansion RAM. Alternatively, a CPU adapter allows for internal expansion.

==== Accelerator RAM ====
Internal or external CPU accelerators often include their own expansion memory. 16-bit CPUs are limited by the 24-bit address space but they can repurpose otherwise unused memory space for their included RAM. 32-bit CPU accelerators aren't limited by 24-bit addressing and can include up to 128&nbsp;MB{{efn|name=binpre}} of Fast RAM (and potentially more).

==== Memory map ====
{| class="wikitable"
|+Amiga system memory map{{Sfn|Greenley|Green|Baker|1991|p=314}}<ref>{{cite web | url=http://oscomp.hu/depot/amiga_memory_map.html | title=Amiga memory map | access-date=August 12, 2023 | archive-date=August 12, 2023 | archive-url=https://web.archive.org/web/20230812110419/http://oscomp.hu/depot/amiga_memory_map.html | url-status=live }}</ref>
|-
! Address    || Size in KB{{efn|name=binpre}} || Description
|-
|align="right"| 0x00 0000 <!--0x0003FFFF-->
|align="right"| 256 || Chip RAM
|-
|align="right"| 0x04 0000 <!--0x0007FFFF-->
|align="right"| 256 || Chip RAM ([[Amiga 1000|A1000]] option card)
|-
|align="right"| 0x08 0000 <!--0x000FFFFF-->
|align="right"| 512 || Chip RAM expansion
|-
|align="right"| 0x10 0000 <!--0x001FFFFF-->
|align="right"| 1024 || Extended Chip RAM for [[Amiga Enhanced Chip Set|ECS]]/[[Amiga Advanced Graphics Architecture|AGA]]
|-
|align="right"| 0x20 0000 <!--0x009FFFFF-->
|align="right"| 8192 || Primary auto-config space (Fast RAM)
|-
|align="right"| 0xA0 0000 <!--0x00BEFFFF-->
|align="right"| 1984 || Reserved
|-
|align="right"| 0xBF D000 <!--0x00BFDF00-->
|align="right"| 3.8 || [[MOS Technology CIA|8520-B]] (even-byte addresses)
|-
|align="right"| 0xBF E001 <!--0x00BFEF01-->
|align="right"| 3.8 || 8520-A (odd-byte addresses)
|-
|align="right"| 0xC0 0000 <!--0x00D7FFFF-->
|align="right"| 1536 || Internal expansion memory (pseudo-fast, "slow" RAM on Amiga 500)
|-
|align="right"| 0xD8 0000 <!--0x00DBFFFF-->
|align="right"| 256 || Reserved
|-
|align="right"| 0xDC 0000 <!--0x00DCFFFF-->
|align="right"| 64 || [[Real-time clock|Real time clock]]
|-
|align="right"| 0xDD 0000 <!--0x00DFEFFF-->
|align="right"| 188 || Reserved
|-
|align="right"| 0xDF F000 <!--0x00DFFFFF-->
|align="right"| 4 || Custom chip registers
|-
|align="right"| 0xE0 0000 <!--0x00E7FFFF-->
|align="right"| 512 || Reserved
|-
|align="right"| 0xE8 0000 <!--0x00E8FFFF-->
|align="right"| 64 || [[Amiga Zorro II|Zorro II]] auto-config space (before relocation)
|-
|align="right"| 0xE9 0000 <!--0x00EFFFFF-->
|align="right"| 448 || Secondary auto-config space (usually 64K I/O boards)
|-
|align="right"| 0xF0 0000 <!--0x00F7FFFF-->
|align="right"| 512 || 512K System ROM (reserved for extended ROM image e.g. CDTV or CD<sup>32</sup>)
|-
|align="right"| 0xF8 0000 <!--0x00FBFFFF-->
|align="right"| 256 || 256K System ROM ([[Kickstart (Amiga)|Kickstart]] 2.04 or higher)<!-- According to the linked wikipage, contradicts "ntrautanen_fi-amiga_memory" -->
|-
|align="right"| 0xFC 0000 <!--0x00FFFFFF-->
|align="right"| 256 || 256K System ROM
|}