Model 100 serial problem

[desiv]

Did you ever find out something isn't working on one of your old computers, and then you couldn't remember the last time that thing actually worked?

I was working on an Arduino/SD/Max3232 based storage device for my Model 100 (I found it online- MyTeSed), but it wasn't working.

I was thinking it must be the Max3232 device, because I know I have been sending programs over serial to my Model 100 off and on for years....

 

Well, turns out the issue is that my TRS80 Model 100 can't SEND data.

It can receive data fine.  And usually I just hook up the serial cables, type : load "com:58n1e" on the M100 and then go to Putty (used to be Hyperterm) and paste the BASIC program.

And that still works.

But my arduino based storage device will require the M100 to send data (such as the filename it wants) and that is when I realized that my Model 100 can't SEND.

And I have no idea when that started.  I can't remember the last time I tried to do anything other than send data from the PC to the M100.

<sigh>

And yes, I did spend hours and hours trying to figure out what was wrong with my Arduino project because I assumed the M100 was working... ;-(

 

I do have another M100 on the way and since that one looks to be much nicer, this was to be my backup/parts M100 maybe...

But still...

I suppose I can try to start tracing back the path for that PIN on the board.  Maybe it is just a bad solder joint or a resistor or a CAP...

Oh well...

Retro life..

As for the arduino based device, I don't think the guy is developing it any further.  Assuming I can get it to work with the other M100, the basic functionality he has is that you can load and save to the SD card.

One thing it doesn't have is way to get a directory of the files on the card.  As I have a Commodore background, I got an idea for expanding the arduino code.

I want to add the ability to request a directory, and then the arduinu will pull up a list of files, and build a BASIC program out of them and send that to the M100.

Kind of like the Commodore's load "$",8 command.

But I was thinking I might be able to have it build it as an actual BASIC program that is a list of the programs on the SD card and you can choose the program to load...

Getting ahead of myself as I don't have a working M100, but it sounds fun...

 

Now I have to wait for my new M100 to show up!!!

Oh well, I have a Mac Classic to reCap tomorrow (probably) anyway...

Edited March 7, 2020 by desiv

[MrDave]

It wouldn't  hurt to do a visual inspection.. but the coco computer won't  spit out data on the serial port if it does not get a ready signal of +5v on the rs232 in pin maybe check that.

 

 

Edited March 8, 2020 by MrDave

[desiv]

Good thought.

Maybe it needs a true null.

My rs232 is rusty... 

I put it away to recap the Mac Classic so I'll have to pull it back out to try that.

OT

Not sure yet on the Mac results. There was a lot of corrosion under/besides on of the caps. ?

tried to clean it up and replaced all the caps.

It was not happy when I first put it back together. Might have been the RAM card wasn't happy, because I pulled that and it seemed happier. Put it back and seemed happier.

Still a few glitches, but I can't remember if it did that before. Some of those old Mac games sometimes did quirky things.

I might have to pull the board back out and clean it some more.  I was just using isopropyl and swabs (and a bit of vinegar for the corroded area, followed by isopropyl).

I keep seeing people use their dishwasher, but I can't seem to get myself to do that. ?

[MrDave]

I think if i aquired a bunch if old computers the same .i would try the dishwasher lol it seems scarey but maybe..lol in the mean time some 99%alchool and a toothbrush wont hurt

 

[desiv]

Just an update..

Finally got around to poking at the serial on the Model 100 again and with a proper cable and connecting to my PC, it is working fine.

So something is up with the arduino/serial port stuff... (possibly the max232)

I'll poke at that later, but nice to know it is still happy.

And now I get to remember how slow 1200 baud really is.

(Also, on the Mac Classic.  I found some iffy soldering on one of the CAPs I replaced, so fixed that and really cleaned the board again.  Including putting the board in the dishwasher.  Working great now!  Whew!)