DIGITAL-LOGIC MICROSPACE MSM286 Series Technical User's Manual page 20

DIGITAL-LOGIC AG
4.11 Serial Port
The serial channels are fully compatible with 16C4/550 UARTS. COM1 is the primary serial port, and
is supported by the board's ROM-BIOS as the PC-DOS 'COM1' device. The secondary serial port is
COM2; it is supported as the 'COM2' device. However, it is possible to disable either or both serial
ports using the Digital-Logic AG BMP utility. (Note: if you disable the primary port and enable the
secondary port, then the secondary port is installed as COM1 by DOS.)
Standard: 82C721 (C&T):
Serial Ports Connectors
Pin Signal
Name
COM1
1 DCD
2 DSR
3 RXD
4 RTS
5 TXD
6 CTS
7 DTR
8 RI
9 GND
COM2
1 DCD
2 DSR
3 RXD
4 RTS
5 TXD
6 CTS
7 DTR
8 RI
9 GND
4.12 Floppy disk interface
The onboard floppy disk controller and ROM-BIOS support one or two floppydisk drives in any of the
standard PC-DOS and MS-DOS formats shown in the table .
Supported floppy formats
Capacity Drive size
360 K 5-1/4"
1.2 MB 5-1/4"
720 K 3-1/2"
1.44 M 3-1/2"
Floppy interface configuration
2 x 16C450 compatible serial interfaces
Function
Data carrier detect
Data set ready
Receive data
Request to send
Transmit data
Clear to send
Data terminal ready
Ring indicator
Signal ground
Data carrier detect
Data set ready
Receive data
Request to send
Transmit data
Clear to send
Data terminal ready
Ring indicator
Signal ground
Tracks Data rate
40 250 KHz
80 500 KHz
80 250 KHz
80 500 KHz
in/out DB25 Pin
in 8
in 6
in 3
out 4
out 2
in 5
out 20
in 22
7
in 8
in 6
in 3
out 4
out 2
in 5
out 20
in 22
7
DOS version
2.1 +
3.0 +
3.2 +
3.3 +
20
MSM286 Manual V6.4
DB9 Pin
1
6
2
7
3
8
4
9
5
1
6
2
7
3
8
4
9
5