Tandy 1000 Programmer's Reference Guide

Chawter 6 I BIOS Services
Entry Conditions:
AH = 2
DL = drive number (0-1)
DH = head number (0-1)
CH = track number (0-39)
CL = sector number (1 to 9)
AL = sector count (1 to 9)
ES:BX = pointer to disk buffer
Exit Conditions:
See “Exits From All Calls” below.
AL
= number of sectors read
Write Sector(s) to Floppy Disk
Write the desired sector(s) from RAM to disk.
Entry Conditions:
AH = 3
DL = drive number (0-1)
DH = head number (0-1)
CH = track number (0-39)
CL = sector number (1 to 9)
AL = sector count (1 to 9)
ES:BX = pointer to disk buffer
Exit Conditions:
See “Exits From All Calls” below.
AL
= number of sectors written
Verify Sector(s) on Floppy Disk
Verify the desired sectorb).
En try Conditions:
AH=4
DL
= drive number (0-1)
DH = head number (0-1)
CH = track number (0-39)
CH = sector number (1 to 9)
AL = sector count (1 to 9)
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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