Investigating Arduino rig to write flash contents, completing IOB6120 probing cable

VERIFYING SIGNAL OUTPUTS OF ARDUINO MEGA USED FOR FLASH WRITING

I whipped up a sketch to assert and turn off the key control signals allowing me to verify that they worked properly on the Arduino I used. All was good with them, except for the data lines that run to the chip. I read the port directly after loading it but got back nonsensical values. 

It turns out that I failed to initialize port A as output, instead it was acting as an input so that when I wrote a 1, it turned on an internal pullup and when I wrote a zero it had no pullup, but in neither case was it driving output to the chip. A simple correction and then all was well. 

TESTING MY SKETCHES TO ERASE SECTORS, WRITE DATA AND VERIFY THE FLASH

My program to write a small bit of the flash chip now worked perfectly. When I ran the dump sketch the data coming out was exactly the 256 bytes that I wrote. Now I had to erase it again in order to program it with the proper contents from the file. I ran the eraseflash sketch and it reported all were erased to xFF. The dumpflash verified this was true. 

HUNTING FOR A TERMINAL PROGRAM OR WRITING A PYTHON SCRIPT TO LOAD FLASH

Each block of 256 bytes involves sending 32 text lines followed by a checksum line - repeated for the total of 128,000 bytes to be written. It is wholly impossible to hand type all those lines without any errors - not even considering the time it would take to accomplish this. 

The proper method is to have a terminal program that waits for a prompt character from my Arduino, such as a '>' and then sends one line of the text file. It should loop through the entire text file loading it to the sketch as fast as the Arduino completes processing each block of the file. 

Not only do I have to send all those lines, roughly 16,500 lines including checksums, but I have to do it a second time for the verification program that reads the flash and compares the contents to the file results. This underscores the need for a programmatic or application that handles the prompt and file transmission.

FINISHING THE PROBING CABLE AND HOOKING UP LOGIC ANALYZER

I moved the gear over near the logic analyzer and set up everything - the FP6120/SBC6120, the IOB6120, the power supply and the Surface Pro with the USB serial terminal program - to begin the debugging process. 

Connecting the cabling is more troublesome than I expected. Some of the connector ends are rounded on the side and won't fit into a standard 2x25 socket. Often I have two female sockets that must be connected, requiring some form of gender adapter such as a two ended male header. It is frustrating but eventually should be ready to run some debugging sessions.

AIR CONDITIONING OUT, PLUS ASR-33 WORK THIS WEEKEND WILL DISPLACE MY WORK

The air condition on the roof of the workshop gave up the ghost last week. It reaches mid to high eighties inside the shop, bearable but not pleasant. The coil sprang a leak, can't be repaired and must be replaced, thus we need to wait on the parts to arrive before the shop goes back to normal temps.

From Friday through Sunday I will switch over to work on the ASR/33 teletypes with a friend, hopefully getting them working properly so he can take them back to his place and put them to good use. 

GLUING RUBBER SLEEVE ON 1130 EXPANDER BOX OPENING - ROUND TWO

I cut some heavy rubber to fit around the opening of the chassis where the many signal wires run out to the 160 pin connector. I bought fast setting epoxy which I expected to hold it in place but the darned glue never set properly nor held the rubber in place. The flaps of the rubber are bent over 180 degrees around the metal of the chassis opening, which results in a fair amount of unbending force from the rubber. Even with clamps holding it for a week, the epoxy is not doing the job.

I switched over to Gorilla Glue, attempting the first of the four flaps this afternoon. The box claims that it requires 1-2 hours with clamps - I will leave it on overnight and evaluate tomorrow. I sure hope that works as my progress is stalled waiting on this mechanical issue to be resolved.