M1000 appears to be working correctly now; x235 P390 server assembled and looking good so far

 VERIFIED STOB SIGNAL WORKING

I set up the oscilloscope to capture ST0B, a phase B signal gated by the sync logic that matches the cards movement through the reader. Indeed, as I had listed as one of the reasons it wasn't in the analyzer capture, it occurs once before the card edge reaches the phototransistors to signal OneDark. It was there on the scope!

VERIFIED IM SIGNALS PRESENTED TO EXTERNAL INTERFACE

The scope was hooked to the IM line on the external interface and showed me the clean pulses that signify that data is latched into the 12 row lines and ready to be sampled. Another great sign!

BUSY AND STOP STATUS, COLUMN 81 AND COLUMN 84 VERIFIED

I triggered the logic analyzer on the occurrence of the 81 CR signal that means we have completed reading the 80 columns of the card and have now moved to the next column position where no holes should exist. Later the counter gets to 84, which is the point when the trailing edge of the card should have moved past the LEDs and all 12 rows should be illuminated. Those signals were there and the error checking successfully varified that no light was seen at 81CR and that no dark was present at 84CR time.

The reader then turned off the BUSY signal since the card had finished passing through the system. Error logic then looks at the state of the microswitch on the input hopper to see if there are more cards to read or the hopper is empty. Since I was reading a single card, the hopper was indeed empty and the error logic raised the condition HOCK for hopper empty check. That turned off the blower motor and switched on the STOP status exactly as it should have.

At this point, it appears the M1000 reader is working properly. I have to get my interface hooked and up and see if it extracts the proper data from some cards. I will leave that for another day. What I can do is see if the external interface is properly reporting card column data. I hooked up the logic analyzer to rows 12, 11, 0, 1, 2, 4, 5, 6, 7, 8, and 9, also watching CSDS whose edge clears the register to enable it to latch in the next card column.

The run worked perfectly. I saw exactly the correct contents matching the physical card I had read. Astute readers will notice that I didn't capture row 3 - purely a result of the limited number of grabbers I had on hand, which allowed me to only capture 12 signals and one had to be a trigger such as CSDS to be sure I was starting the analyzer capture at the correct time.

It is my working assumption that the M1000 card reader is working perfectly now. I only need to re-insert my internal interface board inside and test to determine whether the link to the PC works properly and I can now read and archive cards successfully. That will take place on the next session in the workshop.

ASSEMBLY OF x235 SERVER FOR P390 CONTINUES

I put everything together except for most of the PCI cards which I am leaving out since several of them are essentially unobtanium and can't be jeopardized if the server has issues. 

x235 server begins testing

I was able to bring up the server but received two error notifications. First, the CMOS battery is bad, something that is certain to be true given the age of the system. Second, the fan light is lit on an internal error status panel. 

Dead CMOS battery

An issue with one or more fans

I have ordered a replacement CR2032 battery and will have it in time for my next shop session. Tomorrow we are driving over to Orlando to pick up our new Florida Resident Annual Passes to Disneyworld with lunch in EPCOT for a short day before we return home. Saturday we are driving to meet relatives in Mt Dora and Sunday we are visiting my real estate agents since one of them is still recovering from a breakthrough COVID 19 instance of Pneumonia that had him in the hospital for 30 days and still recovering, requiring supplemental oxygen while at home. Monday should be clear for some time.

The FAN LED should be matched to a fan with a glowing LED but none of the six fans are showing a light. It appears that the bottom fan which cools the disk drive cage is not spinning, in spite of the lack of an error light. This can be caused by an incorrectly mated connector behind the fan, or the power cable poorly mated to the planar (motherboard), or some other issue.

I removed the bottom fan and found that the power connector was out of position and not mating with the fan. It took only a moment to insert it properly, after which powering up the server gave no FAN error LED. One problem down and with the CMOS battery replaced in the next session I should be able to slowly add in the PCI cards and eventually try to boot OS/2 and then run the P390 system.