EGFX · FUNCTION 43ALPHA · USE AT YOUR OWN RISK

EGOV_VALIDATE

Validate a machine-code overlay.

It checks a machine-code overlay that you have already loaded into the Master’s &2C00–&7BFF window, for example with *LOAD name 2C00. The image must start with EGOV, then a 16-bit code length and two reserved bytes, with code from &2C08 (the entry point). The call makes no OS calls and changes nothing on rejection. A valid overlay replies 0 at byte 8 and its length at bytes 9–10; 3 means a bad signature and 4 too large, and PROCegcall stops with EG ERROR. There is no tested example because no sample overlay ships yet.

Parameters

Name	Bytes	Description
`REPLY`	8	0 valid, 3 bad signature, 4 too large
`LENGTH`	9–10	code length (reply)

Assembly

        LDA #43 : STA block+5      ; function
        LDA #0  : STA block+7      ; clear ACK
        LDA #&C0 : LDX #block MOD 256 : LDY #block DIV 256
        JSR &FFF1                  ; OSWORD &C0; block+7 = &A5 on success

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