MDT info wanted

[kf4sqb]

This may have already been covered before, but I got tired of trying to read through all the posts and weed out the info I want. How, exactly, are MDTs "built"? In other words, are they all dumb terminals that require a radio link to a central system to work, or are some of them actually stand-alone 'computers'? Which ones are configured how? I guess what we really need is an 'updated' section on MDTs on Batlabs.

[ericw]

I have started writting info on the MDTs. This is what I have so far. FYI, if anyone knows how to contact the SysOps of BatLabs, let me know. I have sent several emails with no response.

REVISION 01/14/07 1600
DISCLAIMER:
The Motorola MDT products were all uniquely configured to meet the needs of each client. I am writing this using products that I purchased, so your mileage will vary. Please direct comments to Eric Willman at [email protected]

9100-11
The 9100-11 is an eprom based Mobile Data Terminal. The unit that I have is model D3003A (9100-11.) There is a wide access door on the bottom front that contains the eproms for the unit. The unit contains a basic operating system on U5 that appears to be a proprietary system. U7 on my unit is populated, but doesn’t have a label on it. U6 is labeled as the TX (transmit) eprom. U22 is also populated but is labeled as “blank.” There appears to be a custom “personality” prom in U206 that contains the programming for the specific functions of the unit. If you remove this personality prom the unit will function as a basic terminal. A quick glance will look as though the eproms are soldered in but are really pluggable onto the circuit board. Careful removal is required to not bend the pins on the bottom of the chip. There is a soldered in button type battery to the left of the eproms.
There is a flying pigtail power connector coming out of the radio PA deck. This powers the entire unit. If you remove the radio unit, the same connector type is used as the power feed to the terminal. That connector is plugged into the radio. The radio can be removed and the same power connector plugged directly into the terminal to use it without the radio.

The unit responds to simple 2 letter commands. Not all of them have been figured out, but the following is a list of ones I have found so far:
VErsion Displays version of unit
TIme Sets the time of unit
DAte Sets the data of unit
CH Toggles key beep of keyboard
CLr Clear screen
CS Clear system, resets unit
MEmory Shows memory usage
MOde Shows/sets status of serial ports
PRint ??Sends output to printer port
TE ??Returns an error
TX Exit terminal mode
BEep ?
CP ?
ERror ?
LOad ?
MD ?
MS ?
RC ?
TY ?
DElete ?
COpy ??Asks for a filename format
REad ??Asks for a filename format

9100-386
This unit is a PC wrapped up in a special package. It actually contains AMIbios (American Megatrends Inc) that can be accessed during boot-up. The units I have contain 4MB of RAM which operates as standard PC memory and 4MB of NOVRAM which operates as a flash type disk drive. This disk drive does not allow random access as a typical drive. There is a utility that allows for updates to the system. This makes the MDT exist with no moving parts. There isn’t any shock issues to be concerned about with a hard drive.
There is a rechargeable nicad battery pack on the bottom that maintains time/date and bios settings. The battery pack contains 6 cells and I have used 2 cordless phone battery packs in series to replace this unit.
The keyboard contains all the same keys as a standard AT computer keyboard. The F keys are located next to the display. These keys have custom backlighted legends depending on the software in use.
The display is a monochrome 80X25 screen that can be changed using DOS MODE commands. There are 2 PCMCIA slots on the right side of the unit.
I have seen several different configurations of connectors on the bottom of the unit. The units I have use 2 Dsub9 connectors for COM1 and COM2. These appear to be standard PC comm ports. A male DB-25 connector should be for the printer, but it is the opposite gender of typical printer ports. I believe there wasn’t truly a standard back when this was manufactured. A hard reset switch is also included. To my surprise, there is also a SCSI port. Toward the front is a docking port connector.
A 15 pin female connector is used for a radio interface. I currently don’t know any more info on this port. My units have a small 800Mhz exciter coupled to a Maxtrac style PA deck. The PA deck requires a separate source of 12VDC to operate. Under the radio is a multi-pin connector to interface to the radio.
The computer boots up with the DOS operating system and actually runs a stripped version of Windows 3.0. You need to be able to run the system without a mouse. I had to grab the old Win3 manual to remember everything. The only files that are on the system are those required to run Windows in this mode. There are no frills on this system because of the 4MB NOVRAM capacity.
START-UP
The system will prompt with the key (HOME) to enter the BIOS settings. Once inside, the system looks like any other computer BIOS setting. The default seems to work fine.
Also during boot-up a ton of options load and flash by on the screen. One of the options that is significant is the ability to press CTRL-SHIFT at the right point to enter a special system mode. The screen will prompt you to confirm that you want to continue. You need to answer Yes. This will run x:\dos\MIRROR_C.sys and loads the entire novram into the RAM as a form of a ramdrive. The novram can never be edited directly. The novram is always c: and the ramdrive is d:.
Once here, you will be able to make any changes that you wish in the ramdrive to be written to the novram image. After you are complete editing, you type SYNC and the system will write the entire new file structure from the revised ramdrive to the novram. This will make the files permanent.
During a normal system boot the computer will set-up an MS-DOS RAMdisk and copy several Windows files here for random access. There is what appears to be a rather convoluted system of boot-up procedures with the autoexec.bat and WINCPY.bat files. If you print out the files that are referenced, you can see the system that was intended. It is probably easier to simplify this whole copying of system files and replace with a simple command structure during boot-up.
EDITING THE SYSTEM
Getting files onto the system is a bit trickier. Since there is no floppy drive, you need to find an alternate method of moving files. Initially I didn’t have anything that I could use. I realized that there are several programs on the system to facilitate file transfer. In the old days of DOS, they used x:\dos\INTERLNK.exe and x:\dos\INTERSVR.exe as a dos version of LapLink ®. You use a standard LapLink serial cable and run intersvr on one machine and interlnk on the other. This basically maps all the drives between both machines. The system will tell you what drives are mapped to which drive letters. This is fairly straight forward and you can copy files from machine to machine using dos copy commands and the correct drive letters. The floppy, HD(s) and even the CD-ROM drives all get mapped to letters for transferring files.
One of the first files that need to be put on the system is EDIT.com or some other editor for text files. You will need this to edit autoexec.bat and config.sys to get the system customized. You can inhibit the starting of Windows by removing WIN from the autoexec.bat file on the D: drive. Remember, you will SYNC them later. If you want to run Windows, you will need to edit that startup.grp file to stop the auto execution of the MDT/radio programs. This will allow you to run File Manager or any of the other Windows functions.
You may find it necessary to delete the SYSSW and/or the TXWIN directories in order to free up some space on the drive. I don’t plan to use any of the system MDT or radio software so these are just in the way.
THE SYSTEM ENVIRONMENT
The x:\cardsoft directory contains several software items for operation of the PCMCIA slots. Several of these programs have not been fully explored as of yet, but here is a partial list of the ones I have used.
MEMCARD.exe is a program to set up and configure PCMCIA memory cards.
One (or several) of these files are used to read and write compact flash cards that can be used with a PCMCIA adapter in the slot. I have been able to use up to 16MB CF cards so far. 32MB and larger don’t seem to address properly.
I bought several 10MB flash disks on Ebay and had trouble getting them to work on the MDT. I needed to use the FLASHFMT.exe program in order to write the required signature on the card. These units now function just like a standard disk drive using the correct letter. The default drive letters are G: and H: depending on the slot the card is plugged into. The same cards can now also be plugged into WinXP. The S_IDE.exe driver program is started at boot to access those disk cards.
CS.exe is SystemSoft Card Services driver started at boot.
CIC.exe is SystemSoft Card Installation Client started during boot.

The x:\dos directory also contains some dos drivers such as HIMEM.sys and a small program called OFF.com. Typing OFF at a command prompt will turn off power of the system.

In the config.sys file is a number of utilities that are started to allow for many operations. A partial list is below.
x:\dos\SCSI.com starts a driver for scsi hard drives via the local connector.
x:\dos\interlnk.exe starts an interlink driver. I have rem-ed this one out.
All of the drivers for the card slots are loaded in config.sys.
The BUFFERS, FILES, and STACKS statements are included in config.sys.

Since this is a standard computer, you could load extended memory managers and any other TSR programs that you may desire to complete your system. You are of course limited to the capacity issues of the 4MB. I have found that you can add more ram using 2 internal 30 pin ram slots. I have not had time to disassemble a unit and try ram that I have lying around. More later…