Tandy 1000 Programmer's Reference Guide

Chapter 1 I System Calls
Example:
The following program prompts for a letter, converts the letter to
its alphabetic sequence (A = 1, B = 2, etc.), and then reads and
displays the corresponding record from
a file named ALPHA-
BET.DAT on the disk in Drive B. The file contains
26 records;
each record is 28 bytes long.
record-size
relative-record
fcb db
db
buffer db
prompt db
crlf db
equ 14 ;offset of Recordsize
equ
33 ;offset of RelativeRecord
;fieldof FCB
;fieldof FCB
2, "ALPHABETDAT"
25 dup (7)
34 dup(?),"$"
"Enter Letter:
$"
13,10,"$"
func-21H: set -d ta buffer
;see Function 1AH
open fcb ;seeFunctionBFH
mov fcb[record_size1,28 ;set recordsize
get-char: display prompt ;seeFunction 09H
read-kbd-and-echo ;seeFunction
01H
CmP a1,BDH ;justaCR7
le
a1 1-done ;yes, gohome
sub a1,41H ;convert ASCII code
mov fcb[relative-record1,al ;set relative
display crlf ;seeFunction 09H
read-ran
fcb ;THISFUNCTION
display buffer ;seeFunction 09H
display crlf ;seeFunction 09H
Imp get-char
;get another char
all-done: close fcb ;seeFunctionlBH
;to recorda
;record
70

Tandy 1000 Specifications

General

Processor	Intel 8088
Processor Speed	4.77 MHz
RAM	128 KB (expandable to 640 KB)
Operating System	MS-DOS 2.11
Manufacturer	Tandy Corporation
Release Year	1984
Storage	Single or double 5.25" floppy disk drive (360 KB), optional hard drive
Sound	Tandy 3-voice sound
Ports	Parallel, Serial
Graphics	CGA (Color Graphics Adapter)
Graphics Modes	320x200, 640x200