83Plus:BCALLs:4F54

Synopsis

Unofficial Name: GetBytePaged

BCALL Address: 4F54

Gets a byte from a specific page and address.

Inputs

• HL = offset into page where byte is located (4000h-7FFFh).
• A = page where byte is located.

Outputs

• B = byte.

Destroys

• A, C

Notes

Registers A and C are destroyed to restore the page located in bank A after this call completes.

In theory, it works for any ROM or RAM page, but the OS uses it to quickly read a byte from Flash ROM.

Example

Get first byte of page 03h:

 ld a,03h
 ld hl,4000h
 B_CALL GetBytePaged
 ;B contains byte