Radio Shack TRS-80 Model II Reference Manual page 13

MODEL II TRSDOS
Disk Swap Protection
The system now has the ability to detect when diskettes have been swapped
improperly, that is, while a file is open.
TRSDOS
will display an error message when
it detects this condition, and will cancel the read or write operation. See
VERIFY.
New or Changed Supervisor Calls (SVCs)
These are described in the new pages for Section 4.
Name
VDCHAR
PRINIT
PRCHAR
LOOKUP
HLDKEY
OPEN
RENAME
WILD
RAMDIR
SORT
FILPTR
CLRXIT
VIDRAM
PRCTRL
AlBRCV
AlBTX
AlBCTRL
46
Function
Output a character to video
Initialize printer-driver parameters
Output a character to printer
(New) Lookup in a table
(New) Process the (HOLD) key
OpenlCreate a Program or Data File
(New) Rename a file
(New) Process a wild-card specification
(New) Read the directory into a
RAM
buffer
(New) Sort items in
RAM
list
(New) Get information about a currently
open file
(New) Execute
CLEAR
command and jump
to
TRSDOS READY
(New) Transfer video to
RAM
or vice-versa
(New) Control printer operations
Receive character via Channel AlB
Transmit character via Channel AlB
(New) Control Channel AlB
Code
8
17
18
28
29
40
47
51
53
56
58
57
94
95
96/98
97/99
1001101