Tandy 1000 Technical Reference Manual

Tandy 1000
4-4-8. Check of Read Level
(Al Equipment
Technical Reference Manual
(1) Level disk
(2) SKA or user's system
(3) Oscilloscope (not required when the SKA is used)
(B) Check procedure
(1) General method
(a) Use two channels of an oscilloscope and connect them to TP9 and TPIO
(Differentiation amp.) on the PCBA MFD control.
Oscilloscope range
Set both channels,
AC mode, 0.5V
and 2 to the above range. Set either of the
channels to Invert mode and ADD both channels.
(b) Start the spindle motor and install a level disk.
(c) Make the head move to the innermost track.
(d) Execute 2F write operation for one rotation of the disk (250KHz of
WRITE DATA frequency).
(e) Measure the average amplitude (Vp-p) of the read waveform as in
Fig.423.
(f) Calculate the read level by substituting the following expression
with the measured value in item (e) and READ LEVEL calibration
value (see level disk label).
Read level (true value) = Measured value x 100
Calibration value
- 4060 -

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