; entry b.flgs, b.size, b.fcb, b.cnt entry b.rptr, b.wptr, b.body, b.ohead entry .inrdy, .ordy, b.eof, b.wflg, b.wrt ; ; Standard bit definitions .inrdy equ 1; with respect to caller .ordy equ 4 b.eof equ 080h b.wrt equ 040h; mark write access file b.wflg equ b.eof+b.wrt ; ; structure of a buffer. High flag byte available for user. aseg org 0 b.flgs: ds 2; gp flags. eof/wflg/user in lo byte b.size: ds 2; allocated space b.fcb: ds 2; attached fcb, if any b.cnt: ds 2; bytes currently in buffer b.rptr: ds 2; NEXT byte to read from buffer b.wptr: ds 2; NEXT byte to write to buffer b.body: ds 0; Actually b.size bytes b.ohead equ b.body; Extra storage needed for control ; end