M5b BIOS v3.16 FUNCTIONS

                     INTERFACE SPECIFICATION

                           May 1,1992


                             REV. NC
                             

                         GRH Enterprises
                        1129 Stonylake Ct
                          Sunnyvale, CA

.PA
Š.HE                        REVISION HISTORY

REV  DATE      COMMENT
NC   5-1-92   Initial release.



.PA
Š.HE                      FUNCTION DEFINITIONS

     Thå M5â BIOÓ functionó allo÷ programó tï modifù BIOÓ privatå �
datá  withouô knowinç wherå thå datá ió locateä withiî thå  BIOS® �
Theså  functionó  arå accesseä viá thå RESTARÔ 28È vectoò iî  lo÷ �
memorù (0028H)®  Thió vectoò ió initializeä tï á Jumð instructioî �
bù thå BIOÓ Warí Booô code® Thå functionó arå useä bù puttinç thå �
functioî  numbeò iî thå A-register¬  anù otheò requireä argumentó �
iî  thå specifieä registers¬  anä executinç eitheò á RESTARÔ  28È �
instructioî  oò Callinç (executing© thå locatioî  aô  0028H®  Alì �
functionó returî á valuå iî thå A-registeò anä flags® Iæ thå Zerï �
flaç ió set¬  theî nï erroò haó occured»  iæ cleared¬ theî thå A-�
registeò  containó aî erroò code®  Iæ thå erroò codå ió  -1¬  thå �
functioî  ió  noô implementeä (illegal© Iæ thå erroò codå  ió  -² �
theî onå oò morå argumentó arå iî error.


No.  Description     

0    Return BIOS Version Number
     Entry-    A= 0
     Exit -    HL= Version Number in hundredths {0.00 to 655.35}


1    Return Monitor Drive Number for CP/M Drive Number
     Entry-    A= 1
               C= CP/M drive number {0..15}
     Exit -    A= {0..254}: Monitor drive number
                    -2: Drive error
               BC,DE,HL= ?


2    Disable Logon
     Entry-    A= 2
               C= CP/M drive number {0..15}
     Exit -    A= 0: Ok, /0: Illegal drive
               BC,DE,HL= ?


3    Enable Logon
     Entry-    A= 3
               C= CP/M drive number {0..15}
     Exit -    A= 0: Ok, /0: Illegal drive
               BC,DE,HL= ?


4    Set Disk Format
     Entry-    A= 4
               C= CP/M drive number {0..15}
               E:HL= Disk descriptor sector image ptr
     Exit -    A= 0: Ok, /0: Illegal drive
               BC,DE,HL= ?