Mike's PCjr Page

EDIT: All units are gone now! Stand by for an announcement about availability of a new kit.

Hey everyone!

Just a reminder that I still have four of the ten PS/2 to PCjr keyboard converters I made available for sale. Two have what I consider 'good' cables, made after I got the assembly technique correct, and two have what I consider 'iffy' cables, which are missing a layer of electrical tape insulation inside the connector shielding. Both will work, but you will have to be careful how you position the 'iffy' cable models in order to avoid causing interruptions to the data signal. 'Good' units are $25, 'iffy' units are $20 (plus shipping). All units are assembled now and are just waiting on me to finish programming the microcontrollers and do some testing.

Also, as a reminder to those of you who already purchased one, I did adjust the output timing in my code from 40 cycles between level changes to 42 cycles between level changes because, even though 40 cycles should be correct mathematically, my PCjr misses fewer keystrokes with the slightly longer time between transitions. If any of you are having trouble with your adapters and would like an update, please send me a PM.

EDIT: I have installed plastic shims in the 'iffy' units and they are now operating reliably, at least according to my test (which was to plug it in, boot up the PCjr, and type on it while grabbing the connector at the back of the PCjr and wiggling it around -- I didn't count any missed keystrokes for the duration of the test). They should be just as reliable as the 'good' units now, although they still don't look as nice, so I'm still offering them for $20 each.

Also, I've decided to offer USPS Priority Flat Rate small boxes as my default shipping method, which should be $6.80 anywhere in the US, making the total for a 'good' unit $31.80 and for an 'iffy' unit $26.80. I have sold both remaining 'good' units already, though, so the only option for now would be one of the shimmed 'iffy' units until I can get some more parts in.

EDIT 2: I'm down to just one 'iffy' unit with shims left. I will likely keep it as my back-up unit if it goes unclaimed, and I plan on ordering parts for another 10 units as soon as I get word that my PCBs are on the way.

How much effort is it to correct the "iffy" ones ?

Do you have a web page that details all of the project? This was one of the projects that I am pretty clueless about because I spent the last 2.75 years in relocation and new job turmoil.


Mike

Brutman wrote:How much effort is it to correct the "iffy" ones ?

Do you have a web page that details all of the project? This was one of the projects that I am pretty clueless about because I spent the last 2.75 years in relocation and new job turmoil.


Mike

They can't really be 'corrected' properly without ordering more parts (I'd have to cut off the original connectors and put new ones on that were assembled properly). An alternative to that to make them more reliable and less prone to interruption from bad positioning might be to cut some thin plastic shims and shove them underneath the connector shielding above and below the actual connector, but I don't have any material I can try that with yet.

I don't really have a webpage for the project, just an SVN with the source and schematic.

https://www.assembla.com/spaces/ps2pcjr ... ion/source

I have another thread in this forum with more development details, though.

I'd suggest two things:

• Rebuild the flakey ones so that nobody has to worry about it when you sell them. The addition cost is part of the learning curve; but it into the price of all of them if you don't want to eat it. It's going to be hard to unload something that is dodgy.
• Make a dedicated web page that summarizes the result of the thread, kind of what I did for jrIDE back when we got it working. (Alan since has a more complete page.)

I might be interested in obtaining one, but I might want to build it from scratch. I like using my PC 5150 keyboard on my Jr, but being able to use newer PS/2 keyboards might come in handy sometime.

Brutman wrote:Rebuild the flakey ones so that nobody has to worry about it when you sell them. The addition cost is part of the learning curve; but it into the price of all of them if you don't want to eat it. It's going to be hard to unload something that is dodgy.

It'd be easier to do if the only place I've found the connector housings didn't have a minimum order. I might try shimming them first to see how well that helps. I can probably find some scrap plastic around that will do the job, and if it works, I wouldn't have to increase the cost on anything.

Is there any downside to using the PS/2 keyboard on the Jr? Are there games that won't work with the new keyboard or are difficult to play because of the different layout?

Brutman wrote:I like using my PC 5150 keyboard on my Jr, but being able to use newer PS/2 keyboards might come in handy sometime.

Specifically, it would allow (with the use of a CGA TTL-to-VGA converter) hooking a PCjr up to a KVM.

I'm interested in a working one (I don't have the skills to repair one), so please PM me with where I should throw my money and how hard.

Tempest wrote:Is there any downside to using the PS/2 keyboard on the Jr? Are there games that won't work with the new keyboard or are difficult to play because of the different layout?

I don't really know, because I don't have any PCjr-specific games. It works great with Paku Paku, though.

Trixter wrote:

Brutman wrote:I like using my PC 5150 keyboard on my Jr, but being able to use newer PS/2 keyboards might come in handy sometime.

Specifically, it would allow (with the use of a CGA TTL-to-VGA converter) hooking a PCjr up to a KVM.

I'm interested in a working one (I don't have the skills to repair one), so please PM me with where I should throw my money and how hard.

Alright, I'll PM you after work. That takes care of both if the 'good' ones (got a PM for one this morning), and I'll work on the 'iffy' ones this evening to see whether I really need to replace the connectors.

If more people are interested in having one of these, I can price out an order for another 10 soon.

Eh, I decided to go ahead and order some more PCBs for these. I have another project I need PCBs for currently and PCBs this small are really cheap from the company I order from, so it made sense to just go ahead and get them so I could combine shipping. I'll hold off on other parts until I see how much more interest there is.