Specifications

TABLE I 1/0 ADDRESSES AND FUNCTIONS FOR THE QUARK
I/O DEVICE &
ADDRESS REGISTER
FUNCTION (READ I WRITE)
--------------------------------"--------------------,----,---------------------
00-3F Character generator
Special procedure must be
invoked to write
40-SE 1/0 alias
Not recommended for use
SF Parallel printer output port
-VIA CA1: parallel printer Acknowledge input
-VIA CA2: parallel printer Data Strobe output
----_. ---------------------
60
VIA ORBIIRS
61
"
ORA/IRA
62
"
DDRB
63
"
DDRA
64
"
T1C-L
65
"
T1C-H
66
"
T1L-L
67
"
T1L-H
68
"
T2C-L
69
"
T2C-H
6A
"
SR
6B
"
ACR
6C
II
PCR
6D
"
IFR
6E
II
IER
6F
II
ORAIIRA
--- -
-
70-73·
1/0 alias
Output register B / Input Register 8
-PBD-S: General-purpose I/O lines
PBO configured for bell output
-PB6: Simplex port protocol/data input
-PB7: ACIA transmitter/transmitter & receiver
clock output
Output register A / Input Register A
-PAD-7: General-purpose I/O lines
Data direction register 8
Data direction register A
T1 low-order counter / T1 low-order latch
T1 high-order cntr / T1 high-order latch/cntr
T1 low-order latch
T1 high-order latch
-T1 counter used as ACIA baud rate generator
T2 low-order counter / T2 low-order latch
T2 high-order counter
-T2 counter used as baud rate generator for
VIA Shift Register (simplex serial port),
or for full-duplex serial port transmitter
with split baud rates, or as a timer
Shift register for simplex serial port
-CB1: SR clock from PB7 if J3 & J4 installed
-CB2: Tx DATA output for simplex serial port
Auxiliary control register
Peripheral control register
-CA1: Parallel printer acknowledge input
-CA2: Parallel printer data strobe output
Interrupt flag register
Interrupt enable register
Same as address 61 except no "handshake"
--------
Not recommended for use
Megatel Computer Technologies Toronto, Canada
Appendix
Page A-2