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Thread: Tektronix 4052 File Manager and 4052 Advanced File Manager

  1. #1

    Default Tektronix 4052 File Manager and 4052 Advanced File Manager

    I just bought a Unipak 2B for my Data I/O 29B programmer. This Unipak 2B had been tested and calibrated in April 2019.

    I had damaged my Unipak 2 a month ago by trying to create a calibration cable - without the proper mating connector

    Now with my Unipak 2B I can capture several of the ROM cartridges that I had received a couple of months ago.

    First up - capturing the 4052 File Manager and 4052 Advanced File Manager ROM images from the cartridges I got from Bob Rosenbloom.

    The Unipak 2B quickly downloaded and verified the EPROMs in both cartridges.
    I transferred the files in Motorola S-record format to my laptop, and used HxD to import the files and view and save the binary images.

    Then I checked on and both of these cartridges had already been posted:

    I checked the bitsavers binary files against the ones I captured - and all the files matched.

    However, the Tektronix Tekniques_Vol_8_No_01_7.pdf indicates that the 4052R10 Advanced File Manager ROM Pack is for the 4909 Multi-User Management System (hard drive - not floppy drive).

    The 4052 File Manager ROM Pack is for use with the 4907 Floppy Drive - of which I now have two of these floppy drives in non-working condition. Both indicate memory issues, so I need to debug further. The 4907 Service Manual indicates there was a diagnostic ROM and cable to connect to the 4051 system tester to determine which memory IC was bad. I don't have a 4051, so I will have to try to debug with a logic analyzer.
    Last edited by nikola-wan; June 3rd, 2019 at 06:56 PM. Reason: typos

  2. #2

    Default 4907 File Manager booklet

    Here is a link to my scan of the Tektronix 4907 File Manager booklet - with the command summaries:

    Tektronix 4907 File Manager booklet

  3. #3

    Default Tektronix 4907 Floppy Drive power on errors fixed

    I hooked my HP 1630A logic analyzer to the ribbon cable connector from the mainboard to the ROM board - that the service manual indicates can be connected to the 4051 diagnostic box (that I don't have).

    I was able to get the logic analyzer to show the bus read and write cycles and find where the code would find a memory error and turn on the Fault LED with a write to address 4000 hex. The memory location that failed had incorrect data on the low nibble in the lowest 4KB of memory.

    I found replacement Mostek 4027-1 DRAMs from Unicorn Electronics on EBAY and ordered a set of DRAMs.

    One of the two 4907 mainboards had socketed DRAMs - which was the one I started my debug.

    I replaced all four DRAMs in the low nibble of the low bank of memory, powered on the 4907 and still had the Busy, Fault and Clock LEDs lit - but the Fault LED took a fraction of a second to light up.

    The logic analyzer showed the memory test completed on the low memory and now found a memory error in the second 4KB region - which according to the service manual starts at 8KB.

    It appeared this memory error was also in the low nibble of the second memory bank - so I replaced all four DRAMs in that bank, powered on the 4907 and the only front panel LED illuminated was the Clock LED!! Wow - no memory errors.

    I had been careful to put each removed DRAM in sequential locations. Now I began to replace one of the original DRAMs into its original location and do a quick power on - and found one bad memory DRAM in the upper bank and one in the lower bank. This gives me more DRAMs to use to fix the other 4907.

    I then moved the 4907 back near the 4054A to see if the drive worked. I plugged a GPIB cable from the 4054A to the 4907 and plugged in the 4052/4054 File Manager ROM cartridge into the 4054A and powered on the drive and computer - but now the 4054A failed to power on

    I removed the File Manager ROM pack and the 4054A powered on - so the issue was with the File Manager ROM pack. I had previously dumped the File Manager ROM pack - but that was when my Data I/O Unipak 2 was not verifying the EPROMs after the initial copy to RAM. I used HxD to compare my captured files against the oldest dump I had done on this ROM pack in January - and the third EPROM of the set miscompared with the January files. I burned a replacement EPROM from the January file and now the 4054A powered on with the File Manager ROM pack installed.

    Now I typed in the 4907 test program from the 4907 Operators Manual downloaded from I was able to get the Clock set and now all the front panel LEDs were off, and I could also read the incrementing clock time with CALL "TIME"!

    Next I inserted a NOS 3M 8" floppy disk purchased on EBAY and tried to get the test program to format the disk but now the 4054A reports an Error 16 - Device Not Ready. The service manual gives some simple things to check - but I think I need to debug the mainboard floppy interface ribbon cable connection to the drive. I see the floppy drive spindle motor is turning the disk, but I don't see the stepper motor moving the head - nor the head being loaded to the disk.

    I did remove the floppy drive from the second 4907 and plugged it into this one - no difference in behavior - which is why I suspect I need to continue the debug of signals to the drive.

    I'll start with rechecking the power signals - both DC and AC to the drive from the power supply board.


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