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Tektronix 4052/4054 Multifunction modules available.

nikola-wan

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Just looked at my backpack documentation : bsx l/r are interchanged between the communications backpack and the firmware backpack. That is why the expander shows up in the wrong slots.....Clearly an implementation error from Tektronix.

Jos,

Thanks - that matches my test results.

You may want to put a note about that address swap of the RS-232 Printer Interface in your MFM document.

Monty
 

nikola-wan

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@jdreesen, I think we may have an RTC interrupt problem on your Tektronix 4052/4054 Multifunction Module.

I don't remember trying the TransEra 741-RTC test program on your MFM module.

Here is the listing for the test program:
https://forum.vcfed.org/index.php?threads/transera-741-rtc-real-time-clock-for-tektronix-4052-4054.70629/post-70629

The original TransEra 741-RTC ROM Pack passes all the tests in the test program.
For the 1 second timer interrupt test I see the program print an asterisk every second for 10 seconds, then the next test starts.


On the MFM, the tests work until the 1 second timer interrupt - and the program hangs until I cycle power (the BREAK key does not stop the program hang).

Your MFM schematic shows both the ACIA and RTC /irq signals are wire-ORed to the card-edge /irq signal and you also have R10 a 10K resistor pullup to Vcc.

Is there a chance the RTC can't share the /irq with the ACIA?
Answer is no - I just unplugged the ACIA from both your prototype MFM you sent me and the one that I assembled - and they both still hang on the timer interrupt test.

Can you try the RTC test program on your MFM?
 
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nikola-wan

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Testing update.

  1. I plugged the MFM in my 4052 and tried the RTC test program - and when it hung on the timer interrupt test I pressed BREAK once and after several seconds saw a BASIC message that the program was interrupted. Weird thing about this message was it printed very slowly on the display. When I tried typing anything - BASIC was still very slow to print to the display or run any command. In addition the cursor blink took seconds to blink. When I typed INIT, everything returned to normal! I then retested in my 4054A and single BREAK did NOT behave like the 4052. I attribute this to the completely different BASIC ROM code. My conclusion for this test was the interrupt software never saw what it was looking for - and in the case of the 4052 that interrupt software was still running in the background until I ran the INIT command.
  2. I then decided to test whether the RTC ROM actually supported being located in a 4050E01 ROM Expander slot which implies a different bankswitch register setting compared to being located in the left or right slots of the standard ROM backpack. Answer - yes, the original TransEra 741-RTC ROM Pack supports being in any 4050E01 ROM expander slot and the ROM expander being plugged into left or right backpack slots.

Now I wonder whether the difference between the TransEra 741-RTC hardware for the short timing interval versus the MFM use of a 74LS590 could be the source of the problem.

Jos, can you post the schematic you created for the TransEra 741-RTC?
 

jdreesen

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I appended the (partial !) schematic I created. IRQ is directly connected to the RTC chip only. Maybe you can check on you real Transera module if that is indeed the case. Then we will need to check if there are differences in IRQ behaviour between the Transera RTC chip and the one I used ( which has better availability and much better battery interface.)
 

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nikola-wan

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Jos,

My apologies - I have my MFM build and the assembled MFM you sent me both running the RTC test program successfully!

I went back through my notes, emails and finally found the answer I posted in this thread on Sept 27, 2020. I did have the RTCTEST program running back then:
https://forum.vcfed.org/index.php?threads/tektronix-4052-4054-multifunction-modules-available.76192/post-951075

The solution is to use your TEKMFM0903.JED file.

When I reprogrammed my Lattice 22V10 GALs with that JED file - the timer interrupt and other interrupt tests worked - just like they did in my post!

My notes showed that I had tried to create files to assemble your 0903 JED file a couple of weeks after my post - and I must have reprogrammed my 22V10 with my JED file which did NOT verify as the same as your JED file.

Sorry for the false alarm.

Monty
 

nikola-wan

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I removed the labels from one of my Tektronix 4051 ROM Packs and created and printed these labels for my assembly of @jdreesen's design - Multifunction ROM Pack. This assembly did not include the Tektronix RS-232 Printer ROM Pack hardware - or I would have had to cut a hole in the top of the ROM Pack cartridge for the DB-9 connector.

This MFM ROM Pack can hold up to 8 4052/4054 ROM images as it emulates the 8-slot Tektronix 4050E01 ROM Expander plus the board layout supports the TransEra 741-RTC Real-Time-Clock hardware and the Tektronix RS-232 Printer hardware.

The four ROMs that I programmed in the UV-erasable EPROM are ones that are used in programs I currently have in my GPIB Flash Drive image.

Thank you Jos for your MFM design!

My MFM Labels-small.jpg
 
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