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Atom Appendices05

Appendix 5 — Limits and Capacities

The native image and Mac proof map establish the current measured limits.

Resident image

ItemBytes
Z80 code and immutable tables11,648
Fixed non-reentrant workspace453
Linked resident extent12,101
Margin below 16 KiB4,283

Caller-owned source, symbol, pending, descriptor, and stack storage are outside the resident image account.

Native source and output

LimitValue
Ordered source parts1 through 16
Bytes in one Mac source page24,576
Output banksOne, bank zero
Encoded instruction length1 through 4 bytes
Build descriptor15 bytes
Complete 16-part descriptor array80 bytes
One INCBIN input0 through 65,535 bytes

The target is a non-wrapping half-open 16-bit range whose mathematical end is at most $FFFF. Starting at zero therefore permits a maximum capacity of 65,535 bytes, covering $0000 through $FFFE.

Symbols and pending references

RecordBytes
Exact symbol8
Pending reference6

A symbol name contains one through eight significant RADIX-40 characters. A private name has a separate leading period. Globals remain for the complete build; private records remain only in the current global scope.

The Mac proof map assigns 13,312 bytes to symbols, holding 1,664 simultaneous records, and 2,560 bytes to pending references, holding 426 complete records.

Expressions and values

LimitValue
Value-stack entries16
Operator-stack entries16
Concrete final word domain−32,768 through 65,535
Shift count0 through 23
Forward affine addend−128 through 127
Relative displacement−128 through 127
Immediate byte and port0 through 255
IX/IY displacement−128 through 127

Host graph

Preparation limitDefault
General graph parts255; lowered to 16 for native Atom
Dependency depth including entry64
Logical path255 ASCII bytes
Retained logical paths65,536 bytes
SP1 bank ordinal0 through 255; zero for native Atom

The default Mac execution budgets are 200,000,000 native instructions and 2,000,000,000 T-states. The current measured self-build uses 163,392,529 instructions and 1,492,523,777 T-states.

These Mac capacities are not a TEC-1 RAM map. Fixed workspace, maximum Mac symbol and pending arenas, descriptors, and a 256-byte stack consume 16,774 bytes before a source buffer or operating adapter is added.