Download ACC-9PN_____________________________PMAC 32

PComm32 Manual
a. X:$78A to X:$78C. For PC users the addresses are X:$786-X:$787. The Executive program
should take care of this for you, but you might want to check it by hand by issuing a read
command to PMAC (i.e. “rhx$783,10” or rhx$786,2”).
2.
Issue a save command.
3.
4.
Issue a $$$ command.
VME users additionally must write to the mailbox base plus 0x121 to (from the host computer)
completely setup the DPR address.
The most common problem: DPR is in a location that conflicts with other devices or programs in the host
computer’s system. The solution here is to either use a system utility to find a free location for the DPR
or trial and error (also see the application note “How to make sure your DPR is working via Brute Force
Methods”, DPRBRUTE.DOC). Furthermore, most often operating systems provide a means to reserve a
memory block that you specify. Below a remedy for both DOS/Windows 3.x and Windows 95/98 and
NT 4.0 are detailed.
DOS/Windows 3.x Users
DOS based users may use the MSD.EXE utility. You should also use the exclude switch with the
EMM386.EXE entry of the CONFIG.SYS file to tell the operating system to reserve a spot in memory for
the DPR. For example to exclude 16k of byte memory starting at physical address 0xD4000 the
following entry in the config.sys should help:
DEVICE = EMM386.EXE /X D400-D7FF
Use the PMAC Executive Program to test if the DPR is in a good location. Usually the Configure
Communications section has a test DPR feature.
Windows 95/98 & NT 4.0 Users
The “System Resources” dialog box enables you to view and reserve available memory. To get there
click on the “Control Panel” icon and then click on the “System” icon. From there you should see a
tabbed dialog box, click on the “Device Manager” tab. Here your computer resources are listed for you
using a tree view hierarchy. Select the “Computer” icon and then press the “Properties” button. Yet
another tabbed dialog comes up with two tabs, “View Resources”, and “Reserve Resources”. Use the
“View” to scope out available memory, and the “Reserve” to claim your memory. For example to reserve
physical address 000D4000-000D7FF0 click on the “Reserve Resources” tab and then press the “Add”
button, then enter the appropriate values.
1.
Shadow Ram has not been disabled in the computer BIOS. Shadow ram has been known to cause
problems with using PMAC’s DPR. Disable it by configuring your BIOS settings of your computer.
2.
The contents of DPR are not what the user was expecting. PLC’s may be writing to DPR or are
indirectly affecting the contents/enabling of DPR. Also, check that all DPR automatic features (see
DPR users manual) are disabled.
3.
DPR becomes inaccessible after setting I56=1. This is a firmware glitch that has been fixed. This
problem only occurred on PMAC2 for firmware versions 1.15G to 1.16A.
You don’t have DPR. Whatever the reason, you might not have the DPR. For PMAC and PMACLite the DPR is separate board that plugs in alongside the main PMAC board. For PMAC-VME and
versions of PMAC2, the DPR is located on the main board of the controller as a socketed chip.
PMAC-STD users simply can’t have DPR.
4.
Communication Application Notes
107