NanoPeb questions

[RickyDean]

It was a good device till I accidently plugged a power adapter with to much voltage, into it, it killed it, as there guy that built them didn't include a regulator. I purchased from the creator, a replacement cpld chip and he sent one to me, but the 32k part never worked again. I think that he sent me a CLPD replacement for an earlier CF+ card that did not include a built in 32k. Anyhow it's with other parts waiting for me to try to get running properly again. Maybe I can get a binary image of the same chip from a working unit and reprogram this one or a new chip. 

[+OLD CS1]

14 minutes ago, RickyDean said:

I accidently plugged a power adapter with to much voltage, into it, it killed it, as there guy that built them didn't include a regulator.

Ooooh.  Good to know.  Generally I use a USB power source so I should not have to worry, under normal circumstances.  Maybe a 5V Zener across the power input would help that?

[RickyDean]

@newTIboyRob, it may interest you, but here at this github site is a project that builds a emulator that plugs into the side of the TI. Unknown if you may have an electronics friend that could help you build something like this, but could be a cheaper route. FYI:

ti994a-rom-grom-ram-and-floppy-emulator

ROM, GROM, 32K RAM expansion and FDC controller emulator for the TI99/4A computer using a stm32f407 board. Also can emulate the p-card.

More info at https://www.kernelcrash.com/blog/the-ti-99-4a

Heavily based on all the other rom/fdc emulators at https://www.kernelcrash.com

 

https://github.com/kernelcrash/ti994a-rom-grom-ram-and-floppy-emulator

[newTIboyRob]

Thank you @RickyDean   I clicked that larger link and read a bit. I continued with excitement until I came to the line that mentions that it needs to be wired directly to the IO connector on the right hand side, which means I would have to ship the TI out, and also since I myself wouldn't know how to do this and I have no TI electronics friend, the project looks like a dead end for me. Unless of course someone is feeling uber philanthropic here and we can work something out with all this.  Until then, I am just in a holding pattern with the Olympus tape recorder, NanoPeb or even tougher to find CF+7 situation, so it all just plods on here.

 

But I do appreciate all the input and help you have been trying to give me with trying to put this chapter to bed for me. Also good to know about frying gear due to incorrect voltages; I have always been very cautious, actually more like skitterish and leery, when it comes to finding correct voltages, power supplies, tips, etc. Quite an exacting situation.

 

Edited November 3, 2023 by newTIboyRob

[HOME AUTOMATION]

2 hours ago, newTIboyRob said:

...wired directly to the IO connector on the right hand side...

Given the context, I believe directly, probably refers to a lack of need for buffers, level convertors. 

[newTIboyRob]

Well, I saw it used the word "wire" so I naturally thought that was different from simply "connect"?  In other words, the TI would need work to be done on it, thus sent out, as I am not the tinkerer.

Edited November 3, 2023 by newTIboyRob

[RickyDean]

12 hours ago, HOME AUTOMATION said:

Given the context, I believe directly, probably refers to a lack of need for buffers, level convertors. 

I think this means to the connector on the proto board that would plug into the side of the ti99 to provide the data path to communicate between the two, not to the TI99 connector point to the STM unit. FYI. Understood about not having some help, this may not be a solution for you after all, though it is about as cheap as one can go, for a multiple use setup.

[+FarmerPotato]

Long ago I measured the CF7+ current (with 7805 regulator) using a bench supply. I saw a steady 173 mA.
 

 

I extrapolate that the NanoPEB (No regulator!) would surely work with a 5W charger.  Anyone use it from  a USB  port with 500 mA limit?
 

[Kchula-Rrit]

10 hours ago, FarmerPotato said:

Long ago I measured the CF7+ current (with 7805 regulator) using a bench supply. I saw a steady 173 mA.
 

I extrapolate that the NanoPEB (No regulator!) would surely work with a 5W charger.  Anyone use it from  a USB  port with 500 mA limit?
 

The "power brick" I received with my NanoPEB looked just like the brick the powers my parallel-port Zip-drive.  I seem to have misplaced the NanoPEB's brick, but I checked the Zip-drive's brick.  It is rated at 1 amp, so I would think one of those "double" USB chargers, with two connectors, would handle the load.  I have one that is rated for 2.4 amps.

The question is, are those USB chargers regulated 5V or not?

K-R.

[+OLD CS1]

3 hours ago, Kchula-Rrit said:

The question is, are those USB chargers regulated 5V or not?

Loosely.  Not 7805-type of regulation, and better devices had some kind of simple intelligence (usually a standard purpose-built chip) which monitors output and makes input adjustments accordingly.  I have seen plenty of them which run between 4.7V and 5.2V with no current draw.  Depending upon the build quality, most will hold the mid to high end of their voltage until you hit around 70% capacity (700mA from a 1A, 350mA for 500mA, &c.)  Some do better and will hold until around 80% before the voltage begins to fall precipitously.  As with everything, YMMV.

 

I have a well-built charger here rated at 1.5A which will hold 5V up until its cut off for over-draw.

 

Another grave issue with USB chargers (main powered) is how often they have a direct reference to the mains.  This can put mains potential into your device, and if it suddenly finds a return reference... zappo.

 

I test out my mains-powered USB before I use them for anything other than charging devices.  I like my battery packs more.  I have a nice 28Ah one (really not that much, but it does last forever,) and even little cheap-o 2.5Ah units can run a system for quite a while.  Obviously just be aware of usage so as not to get caught by a sudden shutdown (almost all of my packs have either a stay-on four dot meter or some indication of low power.)

[+arcadeshopper]

use a regulated supply.. period that's what the designer specifies .. doing anything else is going to blow up your nano/cf7 sometime..