a2-memory-map v1.0.3

Apple II Memory Map

This is a database of Apple II special addresses intended to be used with language servers. The central element is the file map.json which maps addresses to a set of descriptive strings.

TypeScript Interface

There is a node package that can be used to access the data. The map records correspond to the interface

interface AddressInfo {
    brief: string | undefined,
    ctx: string | undefined,
    desc: string,
    label: string | undefined,
    note: string | undefined,
    subctx: string | undefined,
    type: string
}

The whole database is retrieved as a Map using

get_all() : Map<string,AddressInfo>

To get a single record use

get_one(addr: number): AddressInfo | undefined

The argument addr can range from -32767 to 65535. As an example get_info(0xfded) will give

{
  brief: 'Print character in A',
  desc: 'Invoke output routine whose address is in (56).  Usually prints character in A.',
  label: 'COUT',
  type: 'ROM routine'
}

AddressInfo Fields

• brief: short description suitable for display in a selection box
• ctx: notes on limiting context, such as hardware requirements, applicability to given language, etc.
• desc: long description suitable for hovers
• label: suggested assembler label
• note: any other notes
• subctx: notes on sub context, e.g., specific aspect of a language
• type: data type (e.g. word) or operation type (e.g. ROM routine, soft switch)

Multi-context Records

The map.json file uses logic expressions to delineate information by context, e.g., ctx might have the value "Applesoft | Integer BASIC". The TypeScript interface provides a function to parse the logic and produce an array of records, with each element corresponding to a given context:

get_one_and_split(addr: number): Array<AddressInfo> | undefined

If there is no splitting of the ctx field, no other fields will be split. It is not required to use this function. If get_one is used instead, downstream will receive the logic expressions, which can be parsed in any manner desired.

References

Apple's own documentation is a good starting point. The "Apple IIe Reference Manual" has low level information. The "Applesoft BASIC Programmer's Reference Manual" provides a chapter "Pokes, Peeks, and Calls" with information especially useful to BASIC programmers.

"All About Applesoft" from Call-A.P.P.L.E. has a more in depth treatment.

Sometimes an ambiguity is best resolved by studying the relevant disassembly.