Tandy 1000 Technical Reference Manual

Tandy 1000 Technical Reference Manual
If the flag is set, the 8042 sends off a signal on the interrupt line to the 8088,
resets the timer, and returns to normal operation. The 8042 checks to see
if
it needs to send any more data. If it does, it moves the next data byte to the
output register, sends a signal on the interrupt
line, and returns to normal opera-
tions.
If the output buffer is empty, the 8042 simply returns to normal opera-
tion. Connected to the timer
is the timed data transfer interrupt. When the timer
interrupt
is enabled, the 8042 also checks to see if the timer has timed out.
If it has, then the 8042 transfers the mouse data from the working accumulators
to the output buffer behind the header byte and ships
it to the 8088. It then
clears the working accumulators and returns to the start of the cycle.
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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