 36 pin MDR36 female connector at the computer?? |
| Pin |
Signal |
Abbr. |
Source |
| 1 |
Busy (high) |
BUSY |
Printer |
| 2 |
Select (active high) |
SEL |
Printer |
| 3 |
Acknowledge (active low) |
ACK |
Printer |
| 4 |
Error (Fault- active low) |
ERROR |
Printer |
| 5 |
Paper Error (active high |
PE |
Printer |
| 6 |
Data Bit 0 (LSB) |
D0 |
Computer |
| 7 |
Data Bit 1 |
D1 |
Computer/Printer |
| 8 |
Data Bit 2 |
D2 |
Computer/Printer |
| 9 |
Data Bit 3 |
D3 |
Computer/Printer |
| 10 |
Data Bit 4 |
D4 |
Computer/Printer |
| 11 |
Data Bit 5 |
D5 |
Computer/Printer |
| 12 |
Data Bit 6 |
D6 |
Computer/Printer |
| 13 |
Data Bit 7 (MSB) |
D7 |
Computer/Printer |
| 14 |
Initial |
INIT |
|
| 15 |
Data Strobe (low) |
STROBE |
Computer |
| 16 |
Select Input (active low) |
SI |
|
| 17 |
Auto Line Feed (active low) |
ALF |
|
| 18 |
Host Logic High |
HLH |
Computer |
| 19 |
Return/Ground |
RGND |
|
| 20 |
Return/Ground |
RGND |
|
| 21 |
Return/Ground |
RGND |
|
| 22 |
Return/Ground |
RGND |
|
| 23 |
Return/Ground |
RGND |
|
| 24 |
Return/Ground |
RGND |
|
| 25 |
Return/Ground |
RGND |
|
| 26 |
Return/Ground |
RGND |
|
| 27 |
Return/Ground |
RGND |
|
| 28 |
Return/Ground |
RGND |
|
| 29 |
Return/Ground |
RGND |
|
| 30 |
Return/Ground |
RGND |
|
| 31 |
Return/Ground |
RGND |
|
| 32 |
Return/Ground |
RGND |
|
| 33 |
Return/Ground |
RGND |
|
| 34 |
Return/Ground |
RGND |
|
| 35 |
Return/Ground |
RGND |
|
| 36 |
Peripheral Logic High |
PLH |
Printer |
IEEE-1284 (officially known as 1284-1994, Standard Signaling Method for a Bidirectional
Parallel Peripheral Interface for PCs) refers to a standard set by the Institute
of Electrical and Electronic Engineers. It specifies, among other things, five
modes of data transfer: standard (legacy style), reverse (nibble and byte modes),
and half-duplex or bidirectional (EPP and ECP). It also details cable properties
and connector types. The 1284 standard is an innovation that allows parallel printer
ports to transfer data at many times the standard speed, and also allows for an
array of bidirectional communications and longer cable runs. The Enhanced Parallel
Port (EPP) and Extended Capabilities Port (ECP) both follow 1284 standards, although
EPP was developed prior to 1284"s release. The primary advantage of this technology
is the ability to use devices on a PC"s parallel port that were previously unable
to be used because of communication limitations. However, printers have also benefited
and Hewlett-Packard"s Bitronix protocol, introduced with their LasetJet 4, is
proof. Bitronix takes advantage of 1284"s nibble mode, and allows data to be sent
from the printer to the computer quickly in this manner.
What is the difference between an IEEE-1284 cable and a standard one?
This is often a misunderstood concept. First, let"s make the distinction between
bidirectional and 1284-compliant cables. Applying the 1284 standard to cables,
the IEEE-compliance primarily means speed, and these cables are precisely manufactured
for that purpose. The 1284 standard sets exacting specifications on cable impedance,
shielding, length, and connector styles to insure that they will be up to the
task. Bidirectional cables must simply be able to transfer data in both directions,
and your everyday 25-wire printer cables (and all straight-thru 25 wire cables)
are capable of this; they are not, however, capable of the speed required by
1284-compliant peripherals. Peripherals which are IEEE-1284 compliant (such
as many newer printers) require the use of a high-speed cable, as do most of
the devices that connect to an EPP or ECP.
Describe the connectors that are used on these cables.
There are three official types of connectors: they are termed "A," "B," and
"C." The "A" type is a standard DB25 and the "B" type is your typical Centronics
36 connector. The "C" type is exclusive to 1284, and is intended to be used
on new equipment which conforms to the standard; it is called a half-pitch Centronics
36 connector (HPCN36).
What devices require IEEE-1284 cables?
As a rule of thumb, any device that requires your computer"s parallel port to
be set to EPP/ECP mode is worthy of a 1284-compliant cable. Specifically, most
newer printers, backup devices, scanners, and the like require these cables.
In addition, any parallel device with an HPCN36 connector requires a 1284 cable.
If in question, refer to the user"s manual of that specific device.
Can I use a non-1284 compliant cable instead of one that is?
It is possible, but not recommended. Results can range from limited success
to complete lack of operation.
What are the length restrictions on cables? Do I need to terminate the end
of the chain?
In order to maintain peak performance, the total distance from computer to the
last device should be no more than about 35 feet. Longer runs may be utilized
with a possible drop in overall performance. No external termination is required;
peripherals already come with the necessary termination. At PC Cables and Parts,
you"ll discover an easy to use, information packed web site. Click here to learn
more about Printer Cables. Note: Direction is Computer relative Device. |  36 pin MDR36 male connector at the device?? |
