|
DataMuseum.dkPresents historical artifacts from the history of: CR80 Hard and Floppy Disks |
This is an automatic "excavation" of a thematic subset of
See our Wiki for more about CR80 Hard and Floppy Disks Excavated with: AutoArchaeologist - Free & Open Source Software. |
top - download
Length: 957 (0x3bd)
Types: TextFile
Names: »IOREAD.SRC«
└─⟦b678e5579⟧ Bits:30005502 8" CR80 Floppy CR80FD_0031 ( TELECINE BACKUP )
└─⟦b678e5579⟧ Intel_ISIS_II
└─ ⟦this⟧ »IOREAD.SRC«
IOREAD: LD HL,IOADDR\r ADD HL,BC\r LD D,B\r LD E,C\r LD C,(HL) ; (C):= PORTNUMBER\r IN A,(C)\r \r LD HL,IOVALU\r SLA E\r ADD HL,DE\r \r LD D,(HL)\r LD (HL),A ; X(N-1) := X(N)\r INC HL\r LD E,(HL) ; (D):= X(N-1) , (E):= X(N-2)\r \r LD C,A\r XOR E\r ;---------------------------------------\r ; I F ( X(N-2) <> X(N) )\r ; T H E N NO CHANGE\r ; RETURN\r ; E L S E POSSIBLE CHANGE\r ;-----------------------------------------\r \r NOCHANGE:\r RET Z\r \r POSSCH: LD B,A\r LD A,E\r XOR D\r AND B ; (A):= X(N) XOR X(N-2) AND\r ; X(N-1) XOR X(N-2)\r ; :- CHANGE\r RET Z ; EXIT IF NO STATIONARY CHANGE\r \r LD B,A ; (B):= CHANGE\r AND D ; (A):= CHANGE AND X(N-1)\r \r LD C,A\r LD A,B\r CPL\r AND E\r OR C ; (A):= (NOT CHANGE AND X(N-2)) OR\r ; (CHANGE AND X(N-1))\r ; :- STATIONARY VALUE\r LD (HL),A ; X(N-2):= STATIONARY VALUE\r \r LD C,A ; (C):= STATIONARY VALUE\r LD A,B\r OR A ; OPDATE Z-FLAG\r \r RET\r