Tandy 1000 Technical Reference Manual

Tandy 1000
inter
A.C. CHARACTERISTICS (Continued)
WRITE CYCLE
825318253·5
Technical Reference Manual
8253
8253·5
Symbol
Parameter
Min.
Max. Min. Max.
Unit
tAW
Address Stable Before
WR ITE
50
3C ns
tWA
Address
Hold Time for WR ITE
30
30
ns
tww
WR ITE Pulse Width 400 300 ns
tow
Data Set Up Time for WR ITE 300 250
ns
two
Data Hold Time for WR ITE 40
30
ns
tRV
Recovery Time Between WRITE
1 1
IlS
and Any Other Control Signal
CLOCK AND GATE TIMING
8253
8253·5
Symbol
Parameter
Min.
Max.
Min. Max.
telK
Clock Per iod 380
de
380
de
tPWH
High Pulse Width 230
230
tPWl
low Pulse Width
150
150
IGW
Gate
Width High 150 150
tGL
Gate
Width low 100 100
tGS
Gate Set Up Time to ClK1 100 100
~~-----
tGH
Gate
Hold Time After ClK1 50
50
------~-- --
c--
too
Output Delay From ClKtl
4
j 400
400
tOOG
Out~t-D~F;~~'G-;;teI'('-T--
300
300
twe Write to ClK Set Up 450
350
-------------
---~
NOTES:
1. IOL ~ 2.2 mA
2. IOH ~ -400 /LA.
3. AC timings measured at VO
H
2.2, VOL ~ 0.8
4. C
L
~ 150pF
• For Extended Temperature EXPRESS, use M8253 electrical parameters
Unit
ns
ns
A.C. TESTING INPUT, OUTPUT WAVEFORM
2.2V 2.2V
> TEST POINTS <
08
AC HSflNG INPUTS ARE DRIVEN AT 24VFORA,LOGIC I AND04SVFQR
~~ggl~v ~O~I~:~GG~E~SUREMENTS ARE: MADE AT 2 ov FOR A LOGIC 1
A.C. TESTING LOAD CIRCUI7
C
L
INCLUOES JIG CAPACITANCE
6-148

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