MicroOffice Roadrunner Battery/Charger

[falter]

I got one of these things this weekend and did a cursory look. Unfortunately FedEx Hulk-smashed it. Not sure how with the keys covered by the lid and the unit packed in paper, but somehow they managed to slice off about 8 or 9 of the keys, breaking off their keystems. Guess they were mad about that last insurance claim. Anyway, that's fixable. But, I wanted to see if I could get it running. Specs are it's a Z80 compatible machine with some flavor of CP/M built in ROM, and then it has a bunch of carts it uses for storage and programs. 8 line LCD. The charger is a 7.2vdc wall wart, but curiously it's been split into 4 pins, per photos. The 4 pin connector plugs into the battery pack, which in turn plugs into the laptop. The connector between the battery and the computer internally is the same 4 pin arrangement as between the charger and battery. The laptop will not power up without good battery, and with the wall wart plugged in nothing happens either. Reading the manual it seems to expect to have some sort of charge before it will automatically beep and turn on. There's no power button.

I've done continuity tests and the pins seem to be 'straight through', ie "pin 1" on the charger header is pin 1 on the battery backside, pin 1 on the front side of the battery plugging into the laptop itself, and pin 1 on the laptop's receiver. I'm tempted to just plug the charger straight into the receiver inside the laptop to bypass the battery.

I was trying to figure out what pin delivered what, so far I can only see 3.2V on one pin. I'm wondering if they split the 7.2 in half. The battery pack, which is tiny by 80s standards, has NiCad batteries, and is sealed. There is no info either on the pack itself or in the manual about how many volts it puts out. I'm wondering if anyone here has experience with this sort of arrangement - would it be likely the battery pack sends out *more* voltage than the adapter? I'm wondering, if the pins all seem to be the same, if it'd be smart to just bypass the battery with the charger. I note they all have that weird looks-like-a-mouse marking where the pins are.

Thoughts?

 

[falter]

Just reviving this project for fun and a video.. so, I did end up getting this working, although by accident. I was confused because the power adapter has 4 pins, but after observing the wiring inside the battery pack I realized only two are connected. On each connector for power there is a little 'icon' that looks like a 2 button mouse.. the buttons are where voltage is.

The adapter says it puts out 7.2VDC, but on testing directly on the output pins I'm only getting 3.5VDC. I'm assuming that's just a dying AC adapter. What ended up happening last time I used this thing - I plugged in the battery pack and connected the ac adapter, and while I was looking at other stuff it started working. Remembering that, I plugged the adapter into the battery pack and then tested the outputs from the battery pack, and they gradually rose to 6.2V. After that, plugging the whole mess in yielded a working computer.

So I'm guessing the AC adapter is just hooped, and the batteries, which are starting to leak, have just enough wherewithal to store up enough voltage to work? ie. i should just replace the AC Adapter and ditch the batteries? Or is it possibly designed this way?

Another thing I'm trying to do replace the CR2430s that are installed in the 'RAM drives'. I don't want to break anything - there the lead that connects to the top of the battery - are these actually punched into place? Is replacement just simply bending the thing off carefully? I don't see any solder..

 

[modem7]

... there the lead that connects to the top of the battery - are these actually punched into place?

Spot welded.
E.g. Go to eBay and do a search using: battery spot welder

 

[Qbertnix]

They ar soldered into the pcb. Try searching for CR2430 tagged cells, Google only wants to show me uk suppliers but here's an example

6430401501 | Varta CR2430 Button Battery, 3V, 24.5mm Diameter | RS

uk.rs-online.com

 

[falter]

Thank you! Lacking options in town, I bought the watch battery version. I ended up prying off the battery tabs and then just barely was able to solder them back to the battery without it getting too hot. That seems to have worked for one cart but I think I'll wait and get what you posted above there to replace the other.

 

[falter]

I'm wondering if there is a way to shoehorn other 3rd party software onto this thing. I mean, you can download files via the built in terminal easily enough, and the manual claims the system is compatible with most CP/M software - but there's nothing I can find in any of the menus that gives you a way to actually run a CP/M program. You can list directory contents and format and such, but that's it.

I'm wondering if it'd be possible to take something like ZORK and burn it to the EPROMs the original software carts use, and then run it that way.

 

[modem7]

The adapter says it puts out 7.2VDC, but on testing directly on the output pins I'm only getting 3.5VDC. I'm assuming that's just a dying AC adapter.

To measure 'directly on the output pins', you must have had the AC adapter ("battery charger") disconnected from the computer. In which case, per [here], expected is about 7.2V if the adapter is regulated, or greater if unregulated.

 

[modem7]

... and the batteries, which are starting to leak, have just enough wherewithal to store up enough voltage to work?

Sounds right.

ie. i should just replace the AC Adapter and ditch the batteries? Or is it possibly designed this way?

The AC adapter is labelled "BATTERY CHARGER".
Its power rating indicates an intention to charge the batteries only: 7.2V x 0.12A = 0.9W

( Example: Adapter for Toshiba T1100 {80C88 based} is about 10W )
( Example: Maximum power draw of Toshiba T1000 is "9VDC 1.1A" = about 10W )

 

[falter]

Reviving this thread as I'm playing around with this machine again now that I've had a chance to really read the manual.

So what I'm trying to do is use the terminal program to transfer some basic CP/M programs to the machine's "NVRAM" cartridges and then see if I can run them by changing the file extension from .COM to .PGM. The manual seems to suggest that this is possible - in that it says explicitly the machine can run most common CP/M applications, and that the .PGM extension is their own made up one to tell the machine if a program can be placed in the main menu.

Now earlier in the post I mentioned the batteries were toast, and the 7.2vdc charger was marginal. It seems to be putting out +4vdc. So what I did was solder two wires to the two pins that carry current from the 'sockets' on either side of the cart, and then connected that to a +6V mini-switching power supply. And it seems to be happy with that, EXCEPT when I plug in the RS232 module. Then it starts complaining about 'low battery power' and a really nasty alarm goes off and can't be turned off.

So I'm wondering if in fact the 'charger' did more than just charge, if a bit extra voltage or such. I've looked at the specs of my charger vs the original - it is voltage selectable up to +12v and can do +6V and also +7.5v. It is 0.3a which should be more than enough, the original was 0.12a. Not sure on wattage as the new adapter doesn't mention that.

My question is - is it maybe not getting enough voltage? Would there be much harm if I increased to +7.5vdc?

 

[falter]

I got the Roadrunner to 'talk' to my Thinkpad properly, and was able to attempt to send and receive a file. But as always there was a hitch - it can only receive or send a 'TEXT' or 'IMAGE' file. I'm thinking IMAGE doesn't mean literally a picture since the Roadrunner can't display those.. but unfortunately when I go to try to send a file up from my Thinkpad as an 'image' it wants to select a protocol (Zmodem, Xmodem, etc), and Roadrunner seems to have no option for that.

Dang. This thing really feels like an unfinished pilot unit rather than a production machine. They advertise all these capabilities the user couldn't execute on.