diff --git a/presets/apple2/dos33bin.a b/presets/apple2/dos33bin.a index fb52ed75..40afabd2 100644 --- a/presets/apple2/dos33bin.a +++ b/presets/apple2/dos33bin.a @@ -9,7 +9,7 @@ ; -------------------------------------------------- ; Set PGM_START to desired start of program execution ; - PGM_START must be less than $C000 -; - PGM_START + SIZE must be less than $13000 +; - PGM_START + PGM_LENGTH must be less than $13000 ; -------------------------------------------------- PGM_START equ $2000 PGM_LENGTH equ PGM_END - PGM_START diff --git a/src/machine/apple2.ts b/src/machine/apple2.ts index 504fa7d1..e390ced5 100644 --- a/src/machine/apple2.ts +++ b/src/machine/apple2.ts @@ -195,8 +195,7 @@ export class AppleII extends BasicScanlineMachine implements AcceptsBIOS, Accept const hdrOrigin = this.rom[0] | (this.rom[1] << 8); const size = this.rom[2] | (this.rom[3] << 8); let isPlausible = hdrOrigin < 0xc000 - && hdrOrigin + size < 0x13000 - && (hdrOrigin == 0x803 || (hdrOrigin & 0xff) == 0); + && hdrOrigin + size < 0x13000; if (size == data.length - 4 && isPlausible) { this.LOAD_BASE = hdrOrigin; this.HDR_SIZE = 4;