Parallel Port
Updated W95 Printer Driver
Direct Cable Connection
DMA Printer Port (Uncut!)
Checking for DMA Use
Two Parallel Ports under W98SE
Bidirectional Trivia
Boca Parallel Cards in Server 720
Parallel Port Pinout
Parallel Port Addresses vs. Modes
ADF Sections


95A Parallel Ports
  Port "A" (bottom parallel port) is an ExpressPrint Parallel Port that supports IEEE 1284 (P) compliant devices at up to 2MB/s.  Using vendor supplied multiplexer and software, users can attach up to four supported printers and output 300 dpi complex graphics at the rated speed of the printer and still have capacity left over. Compared to a direct LAN attachment, where data is sent over the LAN twice before being printed, the busmaster ExpressPrint Parallel Port not only reduces the load on the server processor, but prevents the LAN from being flooded with unnecessary printer traffic. 

Port "B" (top parallel port) is a standard parallel port. 

Note: If you experience a problem with a non-IBM device when attaching it to either the parallel port, you might need to go to the Change configuration screen of the system programs and set the port DMA (direct memory access) arbitration level to "Disabled." 



Updated W95 Printer Driver
Found this on Russ Wright's Cannon Support Pages
   Microsoft  released a newer version of the LPT.VXD file for Windows 95 the LPT.VXD is located in the SYSTEM directory 
    This LPT.VXD is to replace the version provided in the Windows 95 service pack #1 and is newer than the version provided with Windows 95 OEM or OSR2.x This latest LPT.VXD is version 4.00.955 

    Click here to download the file A5318.EXE this file contains PRNT5UPD.EXE and README.TXT 



Windows 95 Printing Extended Capabilities Port Support
(Ed. Applies ONLY to LPT A on 95A systems!)
   An ECP provides high-speed printing, and support for ECP and ECP devices is included in Windows 95. If you have an ECP, you can connect either ECP or non-ECP devices to the port. In either case, using an ECP will improve I/O performance, although ECP devices will show the greatest I/O gains. An ECP can be configured in five different ways (defined in the portís Resources properties), as shown in the following list.

Basic *.inf Configuration(s) Description
0  Standard I/O ranges for LPT ports only
1  Standard I/O ranges for LPT ports and any IRQ
2  Standard I/O ranges for LPT ports, IRQ, and any DMA 
3  Any I/O ranges for LPT ports only
4  Any I/O ranges for LPT ports and any IRQ setting

To enable ECP support in Windows 95
1. Consult your computer (or add-in card) manual to determine the IRQ and DMA settings selected for each of the ECP ports you want to use. Youíll need this information to enable ECP support.
2. In the System option in Control Panel, click the Device Manager tab.
3. Click Ports (COM & LPT), and then select the ECP device.
4. Click Properties, and then click the Resources tab. This dialog box shows an I/O range that has been detected automatically.
5. In the Settings Based On field, select Basic Configuration 2. (See the previous table for a description of possible settings for this field.) 
6. In the Resource Settings list, click Interrupt Request, and then click Change Settings.
7. In the Edit Interrupt Request dialog box, type the IRQ value you noted in step 1, and then click OK.
8. In the Resources properties, click Direct Memory Access.
9. In the Edit Direct Memory Access dialog box, type the DMA value you noted in step 1, and then click OK.
10. Reboot so the changes can take effect. After restarting, you can take advantage of fast I/O capabilities offered by the ECP.



Direct Cable Connection
  I've used DCC under W95 to hook up a 9533 to a 77s. A 76s to a 77s. Go to the very detailed Connect Pages at Kime.Net to find out how! Sure beats the hell out of SneakerNet for 70+MB! 


DMA Parallel Port (Uncut!)
  With apologies to "The Micro Channel Architecture Handbook" ISBN 0-13-583493-2, pages 99-100. Spelling mistakes are probably mine.

   "A practical application of Micro Channel technology that breaks the microprocessor bottleneck in printing is making the printer port into a DMA that uses a Direct Memory Access controller to move the data. During a print job, the DMA printer port would briefly take control of the bus, shuttle the data across, and step out of the way.
   The load on the bus itself would immediately be reduced by this technology, but that's only of the tiniest benefit to system performance. This sort of advanced printer port trims the overhead on the bus because it requires only the equivalent of 68,000 characters per second in bus time to support the same 100,000 characters per second data rate. Fewer instructions than characters are required because a 16-bit DMA bus master would be able to move two characters at a time to the printer port instead of the single character permitted by most printer ports in classic bus systems. (Overhead mitigates the two-to-one theoretical advantage of the double-width bus.) Of course, this increase in bus width and consequent bandwidth saving is only an implementation issue more significant with multitasking.
   The important increase in performance to the single-tasking system comes from savings in microprocessor useage. Nearly all of the millions of instructions per second used in the classic bus scenario could be freed up from the microprocessor by the bus master DMA printer port. The microprocessor would need to do nothing but spend a few thousand cycles to set up the DMA transfer, rather than continuously churning through millions of instructions every second. The DMA controller itself would do all the dirty work. The instructions it races through would not impact system performance at all.
   All the time that the adapter and DMA controller are not putting data on the bus most of the time, considering that less than 1/10th (in truth, closer to 1/20th) of the bus bandwidth is used for actual transfer of characters per task. Instead of being fully loaded and unable to perform other tasks with any speed at all, the system with a DMA printer port would have more than 90 percent of it's potential available while the printer is running full speed. If the microprocessor has it's own cache memory, the impact on system performance would be even less, potentially zero.
   The economics of adding a DMA printer port to a high-performance Micro Channel computer are astounding. The parts required to make a DMA printer port are insignificant compared to the cost of an 80386-based computer. As a result, in practical terma a DMA printer adapter could buy back most of that system's performance for less than one percent of the total system cost. In effect, DMA buys you the performance of another 80386-based computer for pratically nothing.
   A true bus master printer port would save more bus cycles and might be easily justified in a multitasking or multiuser system where bus cycles are at a premium. Remember that as earlier stated I/O transfers can take 5 or perhaps 10 percent of the bus bandwidth per task. This means that 5 or 10 tasks might consume a sizeable portion of bus bandwidth at the expense of performance overall. In the single-tasking system, however, the delays introduced by the processor-dependent I/O adapters can be cost-effectively overcome by DMA.



Checking for Parallel DMA Use
Q. I know that the 56/57/76/77/85/90/95 systems use serial and parallel ports capable of high-speed DMA transfers, but how do I know if my system is set up to use DMA? 

A. Simple.  Start the System Program (either from the System Partition on your hard disk drive, or the Refdisk), and look at the Arbitration Level for the serial and parallel ports. The parallel port should be set to Shared 7, and the serial port should be set to Shared 4 for Transmit Arb Level, and Shared 3 for Receive Arb Level.  If your system has two DMA serial ports, the second serial port should be set to Shared 6 for Transmit Arb Level, and Shared 5 for Receive Arb Level.  These are the defaults.  If the ports are set this way, they are using DMA. 

Two Parallel Ports under W98SE
How do I ensure both my parallel ports are enabled on a 95A? 

Dr. Jim Shorney (on sabbatical) 
   Actually, use of the LPT interrupts is software dependent.  Windows' 'standard parallel port', by default, is PIO and does not use interrupts.   Just set one up last night while trying to help Art, and I was able to install both parallel ports as 'standard' with no exclamation points. 

Art Reid 
   I got it using Jim's procedure with a few twists... I made the port setting changes in system setup but left DMA turned on because video manufacturer says I need ECP through DMA on the port for best performance. Next I booted system, went in ControlPanel and added a new ECP port. However, when checking the port in ControlPanel/System I did have an exclamation point on the new ECP port. 
  I had to then change the ECP port @ manually under the resources tab to 278-27A. (No more conflicts). Both the printer and video camera are working fine. Printer on plain LPT port and camera on LPT2 (ECP) with DMA. 



The Hunt for Red ExpressPrint
From: James P. Ward     982-6044   Dept. W13A ,1715, Boca Raton Fl 
   ExpressPrint hardware shipped with all Vizcaya (and later... ) based systems.  The 4-way printer support is achieved  thru a printshare box from Far Point Communications in San Jose.  I believe there is a NetWare and OS /2 driver for this function (Howard Greenberg or Mike Derwin should know).  The planner for all of this was Lew Miller. Hope this gets the wheel rolling...  Jim 

F/MUX Information
   The lone existing F/Mux is all I know to be in existence. I'm not sure if Warp Nine Engineering will ever produce it. Now that USB is out, there is less reason than ever to do so. For more info on the F/Mux, go HERE



Parallel Resistor Networks on 95A
  Bourns 4816P-001 -330  (isolated 33 ohm) and 4816P-002 -472 (bussed 4.7K ohm) for each parallel port. Pdf for the 4800P familyHERE


Bidirectional Trivia
> Peter, is there a patch that allows the reconfiguration of the parallel port  to bidirectional? 

Err ... PS/2 sysboard LPT are bidirectional by nature. There are 3 registers used on LPT ports: 
- data register (LPT-I/O +0) 
- status register (LPT-I/O +1) 
- control register (LPT-I/O +2) 

   The I/O port adress for LPT1 is usually 03BCh on PS/2, the control register is then 03BEh. (You can determine the adress with reading the bytes at 0000:0408 and 0000:0409 in the Bios adress space - the LSB is first, it will read BC 03). 
   If you set bit 5 (direction) of the control register to 1 you can read from the bytes present at the data-register. To permanently read from the LPT-port you need to set the bit 0 (strobe) to 1 you get the bit pattern changes on the port. I use that for the little program that reads the CP codes from another machine. 
   A proper handshake signalling between two computers using the bidirectional mode will most likely work over reading the BUSY lines from one computer to the ACK signal on the other ... you need to read the status of the two lines to determine, which of the two is the sender and which receives data. This is a bit tricky ... but some other software does that already and uses this feature. 
   The PS/2 parallelport is a great device to be used as e.g. input from a Analog-to-Digital converter (however: only 8 bit resolution). For many simple purposes this is truely great. I used the parallel port to control the functions of my AKAI tape-machine ... or used it for some other weird stuff. 
   The system board provides two 25-pin D-shell connectors to the parallel port controllers on the system board. The drivers to the data lines can source up to 15 milliamps and sink up to 24 milliamps. 



Boca Parallel Card on 720
>On another subject, would you have any idea why a Boca parallel port card won't work properly in a server 720?  I tested it in my 95, and it passed wrap tests under DOS, but my friend can't print to it from OS/2 in his 720. 

   Ahem ... I would say the BOCA is too slow.  Remember that the "target" machines for these cards were the Mod. 50 - 80 with the MCA Stage 1 / Stage 2 layout. The 720 is not even "real MCA" but a Corollary system, which uses 80MB/s data streaming mode on all MCA-slots. Therefore only a very limited  number of adapters has ever been announced for it. The "normal" adapters *may* work in the 720 ... or may not. Most worked though - but there was a number of adapters that did not. The Boca cards use very large, very cheap ASICS -as the most of the Multi-I/O card do- which are known to be slow and I got reports that they even fail on faster Mod. 80 (and 76/77, 85, 90 and 95 as well). 
  The Mod. 95 also may handle them good or not - but the "True MCA" machines have a slightly different mechanism / arbitration to handle slower cards than the Corollary MCA bridge - obviously this implementation is not 100% compatible with the MCA Stage 4 of the Mod. 9595 or the Stage 3 of the older 8595-machines. 

>Unfortunately, the instructions warn not to use it in a 32 bit slot as damage might result to card or machine. 
    This card is rather old and originally designed for the slow 10MHz-80286 machines like Mod. 50 and 60, but will also run in 16-bit slots in a 16 or 20MHz Mod. 80. 
    The "Full 32-bit" machines, like 85 / 90 / 95 run on a later and much  faster MCA-specification and therefore *might* cause damage to the card buffering chips (those which connect the card to the bus) due to a much to short cycle speed. 
    The manufacturer - aware on possible problems and upcoming warranty issues - wrote this note in the manual to free himself from  possible loss. Logically. All in all I would say it is not specified and not certified to be used in a Mod. 95. 
     The first thing to be damaged is the card itself - but there is the risk of getting a sort of secondary impact on the machines' systembus drivers, which might get permanently damaged because of overload due to short-circuits in the adaptercard. 
     In case of doubt: I would not use it. Only the manufacturer knows what might happen, and they don't write such a (negative) passage in the manuals just to tease the users. 



Parallel Port Connector Pinout
PIN SIGNAL NAME PIN SIGNAL NAME
1 -Strobe 14 -Auto FD XT
2 Data 0 15 -Error
3 Data 1 16 -Init
4 Data 2 17 -Select in
5 Data 3 18 Ground
6 Data 4 19 Ground
7 Data 5 20 Ground
8 Data 6 21 Ground
9 Data 7 22 Ground
10 -ACK 23 Ground
11 Busy 24 Ground
12 PE 25 Data parity***
13 Select  

*** Data parity is a function of parallel port A only). 



Parallel Port Addresses vs. Modes
Parallel Port
Address
Parallel Port
Address
Parallel 1 Parallel 3
Compatible
03BC-03BF
Compatible 0278-027B
Enhanced
1278-127D
Enhanced 0278-027D
Extended
1278-127F
Extended 0278-027F
Parallel 2 Parallel 4
Compatible
0378-037B
Compatible 1378-137B
Enhanced
0378-037D
Enhanced 1378-137D
Extended
0378-037F
Extended 1378-137F

Notes:
   Many software drivers cannot handle addresses outside of 278-3BF. Parallel 4 (all modes) and the enhanced/extended Parallel 1 addresses are probably NOT supported unless you use OS/2 or a *nix. 
   Parallel 1 has a primary address of 3BC-3BF. IBM says that the DMA controller does NOT support that address, so that's where the odd 1278-127F come from. 

Compatible is the old-styled unidirectional printer port 
Enhanced is what? 
Extended is bidirectional mode. 
Enhanced/Extended ports use DMA. I don't know what the other difference is. Note that the enhanced port is one bit more than a standard port. Extended ports are two bits wider. 

W95 Trivia
   I have installed an ECP Printer Port under "Add New Hardware". Go to the ECP Port's Resources and select the correct address and DMA Channel. It appears that DMA Channel 1 is used by DMA Arbitration Level 1. Am unsure if that's true, but it still works. I don't have a parallel port device yet to verify this other than my digital camera. 
   I also hacked msports.inf in the [1aaa] section so that I had the extended port address. Dunno if that works better than the Compatible address, but it "looks" faster. Odd, but the IBM manual lists the enhanced mode, not the extended mode. The addresses in the adf for the planar are the ones ending with a "d". Does this mean compatible mode only? Or does it just show the non-DMA ports? Help! 



ADF Settings for Parallel Ports
Not all systems support these settings, nor will they be in the same order. 

Parallel Port x
     The  parallel port x  can be set as Parallel 1 through 4 or the port can be disabled. 
   <Parallel 1 ( io 03bch-03bfh 1278h-127fh int 7)>, Parallel 2"  (io 0378h-037fh int 7), Parallel 3 ( io 0278h-027fh int 7), Parallel 4 ( io 1378h-137fh int 7), Disabled 

Parallel Port x DMA Arbitration Level
      The parallel port x connector can be set to any one of the available DMA arbitration levels.  If the level selected is shared then other devices can be set at the same level.  If the level selected is dedicated then only this device can be set to that  level. 
     <Shared level 7>, Shared level 6, Shared level 5, Shared level 4, Shared level 3, Shared level 1, Shared level 0, Level 7, Level 6, Level 5, Level 4, Level 3, Level 1, Level 0, Disabled" 

Parallel Port x SCB I/O Address
   The parallel port x connector can be set to any one of the available SCB I/O addresses. 
        <8100-8102>, 8900-8902, 9100-9102, 9500-9502, A100-A102, A900-A902, B100-B102, B900-B902, C100-C102, C900-C902, D100-D102, D900-D902, E100-E102, E900-E902, F100-F102, "Disabled 

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