Poor Man's TPDD - Raspberry Pi Zero

[dgrissom]

Poor Man’s TPDD

 

I previously started this as a post on the  "TRS-80 Model 100/102/200, NEC 8201A/8300, Kyocera KC-85"  Facebook page.

I've decided to upload the instructions as single PDF file on this forum as it is a better platform to share this information and files.

 

Note:  There is at least one other example of this on the net.  However, I found it after I made my prototype. 

 

Being retired and on a strict hobby budget, I decided that it would be great to have Portable Disk Drive to go with my TRS-80 Model 100.  Unfortunately, most solutions were way over my current budget of zero dollars ($0.00).  

 

I rummaged through my inventory of items on hand and created a modern drive using a $10 Raspberry Pi Zero W (a gift) , a very old USB Serial Cable (thrift store), a “lipstick” style phone USB/recharge battery (another gift) , and a few other small items.

Since, I already owned everything; I figured that a “headless” Pi should work. 

 

I set up the Pi using a fresh Raspberry Pi OS (no desktop).  After enabling SSH, I created a share (TPDD) and passed over mComm (python version) from Kurt McCullum’s Club 100 Member Upload Library.  I was able to easily get it running on the on the Pi using a TPDD shared folder.

 

I added a switch to shut down the Pi when I didn’t need it.   Next, I plugged in the USB Serial Cable and battery.  It worked!

mComm automatically starts when the Pi is turned on.   I pass the M100 files to my Pi through the shared directory on my PC.  The Pi’s microSD card will hold almost all the Model 100 files in the known universe.

 

This works better than I could have imagined and meets my current budget of nearly 0(zero) dollars.

I am compiling I've compiled the steps needed to set this up and will post them if there is an interest?

If you don’t have the materials, this should set you back around $50 or less.

 

(Note:  I am not selling this item.  I hope others may enjoy it as much as I have!

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Attachments: The build guide:  PoorMansTPDD.pdf 

Also: A ready to use collection of Club100 files (public domain files in the correct format for "mComm") for folks to test.  

 

TPDD.zip

Poor Mans TPDD.pdf

Edited December 5, 2020 by dgrissom
Links not working in Poor Mans TPDD.pdf

[dgrissom]

-----

Attachments: The build guide:  PoorMansTPDD.pdf 

Also: A ready to use collection of Club100 files (public domain files in the correct format for "mComm") for folks to test.  

 

In reviewing the TPDD.zip (after posting it), I found a few files that slipped through the cracks.  ?

If your PMTPDD appears to hang while listing a directory (fixed by a simple "reset"), then most likely you've found one of the missed files.   It will be lowercase format.   Most of the files were ".do" moved back to the main directory after I converted the ".ba" files.

 

To fix the files, simply open the "TPDD" share you created, navigate to the the CLUB10 folders and rename them to UPPERCASE(6.2) format and you should be good to go.  I may update the original TPDD.zip at a later time.  I am converting a few additional files to add to it and my personal collection.

 

Also, I have not tested most of the programs; I just converted them, so your mileage may vary...  ?

 

David G

[Airshack]

Thanks David!

[hwrd]

This is great, thanks!

[dgrissom]

Just now, hwrd said:

This is great, thanks!

Glad you like it.

 

It is working great for me.   I am no longer tethered to a PC (just a tiny Raspberry Pi)!

 

My only improvement I am contemplating is locating a small protective plastic case for it.  

 

[Omega-TI]

Hope you don't mind, but I felt the need to rotate the image for a better view, then I decided to enhance and dress it up a little for online viewing...

 

[dgrissom]

2 minutes ago, Omega-TI said:

Hope you don't mind, but I felt the need to rotate the image for a better view, then I decided to enhance and dress it up a little for online viewing...

 

snip.

No, that's fine. ? 

The original images were posted on Facebook.  For whatever reason,  I couldn't upload them and with the correct orientation.  I just pushed them here more or less intact.  Due to editing restrictions, I couldn't fix them later. (Too cheap to join AtariAge at this time.).

 

Omega-TI, do you own a M100,102,or 200?  Just curious?

[Omega-TI]

2 minutes ago, dgrissom said:

No, that's fine. ? 

The original images were posted on Facebook.  For whatever reason,  I couldn't upload them and with the correct orientation.  I just pushed them here more or less intact.  Due to editing restrictions, I couldn't fix them later. (Too cheap to join AtariAge at this time.).

 

Omega-TI, do you own a M100,102,or 200?  Just curious?

No, I used to own an NEC PC-8201A (as seen in the photo below).  However, I used to sell Model 100's!    If I could get something affordably like this pre-built and ready to go, in a case, I'd probably get a Model 100 for kicks.  I used mine quite extensively in college.  There is simply more out there for Model 100's than the old NEC.

 

[Omega-TI]

1 hour ago, dgrissom said:

It is working great for me.   I am no longer tethered to a PC (just a tiny Raspberry Pi)!

My only improvement I am contemplating is locating a small protective plastic case for it.  

 

Man, this is just BEGGIN for a 3D printed enclosure!

[dgrissom]

Just now, Omega-TI said:

 

Man, this is just BEGGIN for a 3D printed enclosure!

Don't own a 3D printer (it is on my wish list.) However, these look easy to adapt and seem pretty slick.

 

Amazon.com: Onwon 5Pcs Black Waterproof Plastic Electric Project Case Junction Box 3.94 x 2.36 x 0.98 inches(100x60x25mm).: Home Audio & Theater

[dgrissom]

Omega-TI

 

I don't know if you reviewed the PDF attachment.

 

I used to own a TPDD.  I never liked it.  This device, I like.  (Similar to jedimatt42's TIPI!)

 

Few parts are really needed.  Many you may already have?

Guide should be easy enough to follow.

 

Highest cost items are REXCPM ($60) or REX# (a little cheaper).

M100's are getting on the expensive side.  Fun, productive, and retro!  I know you like that! 

 

[Omega-TI]

Well, I have my fingers in too many hobby pies at the moment, and between work, family and chores I seriously don't have to time to build up yet another system.

[+jedimatt42]

This was a slick build. I strayed a little... I cut out the 'PM' and spent money... Already had the PI and cables and adapters... but after using an old charger that looks just like @dgrissom's, I saw this:

 

 https://www.tindie.com/products/pisugar/pisugar2-battery-for-raspberry-pi-zero/

 

And they have a ready to print case, that the printer is currently working on... 

 

The rechargeable battery device has a software suite that installs on the PI and provides a web interface to configure a few things...

1. there is a momentary switch, so you can choose press, double tap, or long press to trigger shutdown, or some other script... 

2. there is a RTC, so the PI can use the correct time when you take the model100 out without WIFI access. 

 

So, the only part of the software setup I changed, is to not add the config.txt entry for gpio-shutdown. 

 

---

I learned some cool things following these instructions.. lots of ways to accomplish similar tasks on linux... so @reboot entries in crontab were new to me. That one will stick with me. 

 

And BIG THANKS to @dgrissom for the guide! 

 

---

Now, if I could find a good USB -> 25 pin serial on a short 3 foot cable, I'd solder that sucker to the underside of the PI-Zero-W, and feel like it was really tidy... 

 

Edited December 18, 2020 by jedimatt42

[dgrissom]

10 hours ago, jedimatt42 said:

 

And BIG THANKS to @dgrissom for the guide! 

 

---

Now, if I could find a good USB -> 25 pin serial on a short 3 foot cable, I'd solder that sucker to the underside of the PI-Zero-W, and feel like it was really tidy... 

 

I love the power battery you've chosen, its so small!  I may save my pennies and get one after Christmas!

 

I've thought about disassembling one of my USB/RS232 cables to create a custom Model 100 cable.   (Slice open the cover, solder on a properly pinned out 25 pin connecter, and remount it in a D25 shell. 

Version 1 would have a shorter more flexible micro USB cable. 

Version 2 would mount directly to the PMTPDD and plug directly into my computer.  (No cable).

(I've thought about a number of variations on the RS232/Pi connection.)

 

Since you have REXCPM, you may want to try this.

• SSH into your RPi and download/install "minicom".
• Run it and set your parameters to 19200 8N1, terminal VT102, etc.  Save your settings. (use: CTRL-A, O to do this.)
• Once saved, you can restart minicom at any time in SSH by typing "minicom" after logging in with SSH.

 

 

After booting your PMTPDD and minicom is running:

Start a CP/M session on your M100/102 and use "F3" to redirect your session to "RS23". (Thanks to @arcadeshopperfor nudging me on this!)

Now the fun!  Instant 80-column wireless output to the host machine!

Best part is that it doesn't interfere with your "mcomm" connection,

(Just don't access your TPDD while running the minicom session.)

 

BTW, I can't wait to see what you do with this! ?

 

David G.

 

[Th3Tink3r3r]

Hi,

 

Could you share the pi image? I can put it on my dropbox if anyone is interested.

 

 

/Fredrik

[dgrissom]

On 1/20/2022 at 2:36 AM, Th3Tink3r3r said:

Hi,

 

Could you share the pi image? I can put it on my dropbox if anyone is interested.

 

 

/Fredrik

I really appreciate your interest in my Poor Man's TPDD project!  I enjoyed putting the project together and know of several folks that have successfully used it.

I can't upload an image on this site or directly to other users:

• Security - This is a priority as all of my personal card images have secure data that could be extracted to gain access to my Wi-Fi, etc.  Also, there is other personal data on the card.  I might be able to create a "sanitized" image.  However, I would not be able to validate whether or not the software still works.
• Personalization - I have personalized by TPDD to work with several local resources as well as working documents on the card that may not be useful/useable to other users.
• Compatibility - My current image is based on RPi's Buster and is set up for a specific Raspberry Pi model.  I set it up using a Raspberry Pi Zero W.  It probably won't work with any other Raspberry Pi's (including the newer Raspberry Pi Zero 2 W as well as other Pi units).
• Image Size - While I know that you have offered the use of your Drop Box, my current card's image size is 8gb. Even compressed /zipped this image is still quite large.  I've found that all 8gb devices are not the same and there is a chance it will not work with other 8gb micro-SD's.  Personally, I wish I had a 4gb card to work with as the 8gb is overkill for a Model 100/102.

With all that said, I would be more than glad to help you set up your own image using this forum. ? It only takes a few minutes with a computer and a few pieces of software.  This should help you and others to better understand what you need to do to maintain it.  In its simplest form, the device only requires a suitable Raspberry Pi, suitable SD card, RS232 adapter, and power source.  The pdf file, downloadable in the first post, will guide you through the process.  If at that point, you wish to share your image, have at it.

 

Thanks, DG

[waynel]

On 12/5/2020 at 2:25 PM, dgrissom said:

I previously started this as a post on the  "TRS-80 Model 100/102/200, NEC 8201A/8300, Kyocera KC-85"  Facebook page.

I've decided to upload the instructions as single PDF file on this forum as it is a better platform to share this information and files.

I know I'm two years late to this discussion, but I want to thank you for posting your information here. 

 

It's a real shame that so much Model 100 information is locked up in Facebook and other platforms where it is inaccessible to those of us who cannot (for various reasons), or choose not to (for many other reasons), patronize these mega platforms.  

 

Sure, this web forum may disappear one day, as well.  Even Club 100 is rife with dead ends.  So it's important for useful information like this to be shared in as many places as possible to make it durable for the future.

[dgrissom]

Thanks for your comment!  ?