; JHA 7/29/2018
; ocr'ED an IMAGE of this, then cleaned it up a bunch
; from file IMSAI_CPM_System_Users_Guide_Version_1.31_Rev_2_Mar77.pdf
;EZEOOTS.ASM VERSION 1.0 10/27/75 JRB
;AUTOMATIC BOOTSTRAP SIMULATOR FOR STARTING CP/M
; IN SYSTEMS IN WHICH AUTOMATIC BOOTSTRAP DISK
; INTERFACE FIRMNARE HAS NOT YET BEEN INSTALLED.
;NOT NEEDED ONCE NEW PROM'S ARE INSTALLED IN FIF.
;THIS IS THE SHORT VERSION, SUITABLE FOR TOGGLINC IN.
;A SEPERATE VERSION, WITH ERROR RETRIES, IS
; RECOMMENDED IF YOU HAVE A WAY OP KEEPING IT RESIDENT.
BSBASE EQU 4000H ;YOU MAY CHANGE THIS TO ANY VALUE
;GREATER THAT 7FH.IF BELOW 4000H
;PROGRAM MUST BE RELOADED EACM
;TIME YOU WANT TO BOOT CP/M.
EXIT EQU O ;WHERE TMIS PROGRAM EXITS TO
DISK EQU 0FDH ;FLOPPY DISK COMMAND OUTPUT PORT
ORG BBASE ;THIS IS ALSO START ADDRESS
;SET DISK INTERFACE STRING POINTER
MVI A,10H ;"SET STRING POINTER 0" COMMAND
OUT DISK ;SEND COMMAND TD DISK INTERFACE
MVI A.BCMD AND 0FFH ;LO ORDER OF STRING LOC
OUT DISK ;SEND TO DISK
MVI A,BCMD SHR 8 AND 0FFM ;HI ORDER HALF OF SAME
OUT DISK
;READ SECTOR. ONE TRY ONLY.
LXI H,BSTAT ;POINT AT STATUS BYTE OF STRING
XRA A ; SET ZERO IN A
MOV M,A ;ZERO STATUS BYTE
; N. B. A=0 IS ALSO Disk COMMAND TO DO STRING 0
OUT DISK ;DO IT!
WAIT: ADD M ;LOOK FOR NON-0 STATUS
JZ WAIT ;KEEP LOOKING TILL IT COMES
;ALL THAT IS ABSOLUTELY ESSENTIAL AT THIS POINT IS TO JMP 0.
HANG: CPI 1 ; THIS CODE CAUSES A HAND HERE IF
JNZ HANG ;..DISK READ FAILED.
JMP EXIT ;READ WAS ok, GO TO ROUTINE READ IN.
;PRE-INITIALIZED COMMAND STRING FOR DISK (MUST BE IN RAM)
BCMD: DB 21H ;CONMAND BYTE: READ, UNIT 1
BSTAT: DB 0 ;STATUS BYTE, SET BY DISK WHEN DONE
DW 0 :TRACK 0 (2 BYTES)
DB 1 ;SECTOR 1
DW 0 ;BBUFFER ADDRESS: READ TO LOCATION 0
END DBASE
