Sunday, November 21, 2021

Continuing the card archiving, finished retro chip tester pro, wiring internal Documation controller

 THREE MORE BOXES OF CARDS READ AND ARCHIVED

The number of reading errors varies dramatically from box to box of card and I don't yet see a pattern to warn me of troublesome decks. A two box set of cards that load DMS V2 M11 (the disk monitor system, compilers and utilities that are the equivalent of the operating system for the IBM 1130) read so smoothly that I only had three cards fail to verify, two of them were errors in the verify pass and one was an error when reading a card on the first pass. A box of contributed programs from COMMON, the IBM users group, on the other hand, was a nightmare where a hundred card deck might require ten or twenty passes to get the data read and verified. 

With the card contents captured, I could move on to phase 2 of the archiving. That is an examination of the decks to understand what they are, which guides me to further work. Sometimes I realize I have two more more logical items in one marked deck and split them up.

I want to end up with a folder for each deck with a descriptive name. In it there will be a text file where I describe what this deck represents and highlights any errors or missing elements. In many cases I run the code on the IBM 1130 simulator to make sure I understand it properly. Where it makes particular sense, I include a text file that is the printer listing output. 

The files I captured include printer art, games, utility programs and the disk monitor. As an example of a very useful utility, I came across programs that write various pause and error conditions to the console printer. In normal practice, a program issuing a PAUSE command will display four hexadecimal digits in the accumulator, visible only on the lights. There is no hard copy evidence of this, so that once you push Start and move past the pause, all record is gone. 

Other conditions produce monitor errors as four hex digits in the accumulator. This utility will type ERROR xxxx on the console, drawing more attention to the issue and making a hard copy. This was handy when I was trying to run a printer art program, because it had a defect that lead to the monitor detecting error F001 and pausing execution. It was helpful to see ERROR F001 printed because you might miss the error otherwise. 

When the card reader runs out of cards, the system waits with a particular address displayed in the console lights - one is accustomed to the monitor waiting and may not carefully examine the lights to distinguish an error from a normal end of job stop. 

I wrote up the order of the decks for someone who wanted to run a fresh install of DMS V2 M11 on a blank disk cartridge - along with the decks themselves. This makes the archived decks more useful than an assemblage of randomly named deck images. 

FLASHED FIRMWARE FOR RETRO CHIP TESTER PRO, FINISHING ASSEMBLY

The last step in building the chip tester designed by Stephan at 8bit-museum.de is to load the code onto the Atmel 2560 chip. The PCB he provides comes with the Atmel soldered on, but not programmed. I picked up a suitable programmer, hooked up and flashed the chip.

I brought it up. All lights were good and the menu system works on the LCD display. I started in testing some chips that weren't covered by the other testers I own, such as the 7475 and CD4050. However, some other chips that are supported came up with errors upon test. More worrisome, either the 12V or the -5V power supply LEDs blinked off during these failed tests. 

I suspect that something is not working properly, applying the wrong rail voltages or hooking more than one supply voltage to the same pin. A construction error undoubtedly. There is a diagnostic firmware load that will selectively apply the rails and signals to each pin, letting me track down the issue.

INTERNAL CONTROLLER FOR M1000 READER GETTING WIRED UP

I removed the old socket from my previous controller and moved the wires over one by one to the Arduino shield that will connect a Mega2560 with my controller sketch. I finished all the signals that were used by Brian Knittel's controller but two additional lines from the reader are used by my controller - Motion Check (MOCK) and Busy. I have to identify the wires for these two and hook them up, along with the LED and pushbutton. 

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