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Replica PCjr

To answer your question brutman. Why not? I think it would be fun to do if it's possible, plus we could come up with a PCjr board that would fit in a standard AT style case, or ATX, admittedly that would be far off, but it is JUST an idea.
 
Rainbow ponies for everyone!

No seriously, I'm really confused here. It makes no sense to recreate something that is already in plentiful supply. There are so many other things to be working on that pass the sniff test:

  • An IDE controller that the Jr can boot from
  • A memory expansion card using an SRAM chip or two instead of DRAMs. This is faster, lower power, and gets rid of the DRAM controller.
  • An Ethernet card based on whatever the C64 and Apple ][ people are using. (Better, stronger, and faster than parallel port attach ones.)
  • Another run of PCjr bus to ISA adapters so people can experiment with ISA cards on their Jrs.
  • Updated BIOS or a BIOS ROM extension for 3.5" 720K floppy support.
  • An upgrade to a 16450 UART instead of the built in 8250 UART
  • A serial port card that goes in the modem slot
  • An XT or AT keyboard adapter


Jrs are unwanted, low dollar machines - go adopt one today. Save the recreation work for 50 years from now.
 
mbbrutman said:
An XT or AT keyboard adapter
Click to expand...

This is where I'd like to start. (ok, I want to do #'s 1,2,4,5 too, but this one is pretty low hanging fruit I think)
I would use my jr a lot more if I could use a normal keyboard attached to my KVM switch. We've already got the AT->XT keyboard converter project, all that needs to be done (I think) would be an rj-45 adapter instead of 5 pin DIN and some different decoding logic in the uC.
 
yes, you'd still use your existing PCjr keyboard cable.
The adapter would have a PS/2 connector on the AT side and an RJ45 socket on the other:

AT keyboard------>[ps/2 socket]:Adapter:[RJ 45 socket]----->pcjr cable----->PCjr

I could probably even rip apart an old telephone to get RJ45 socket and see if it can be bolted onto the existing at2xt keyboard PCB somehow (with a little duct tape I'm sure)
The real trickery is learning the code in the microcontroller, but I am pretty sure that's within my realm of understanding, since I already do x86 assembly for a living.

edit: oops. it's rj-11.(telephone connector) Too much time spent playing with ethernet.
 
mbbrutman said:
Rainbow ponies for everyone!

No seriously, I'm really confused here. It makes no sense to recreate something that is already in plentiful supply. There are so many other things to be working on that pass the sniff test:

  • An IDE controller that the Jr can boot from
  • A memory expansion card using an SRAM chip or two instead of DRAMs. This is faster, lower power, and gets rid of the DRAM controller.
  • An Ethernet card based on whatever the C64 and Apple ][ people are using. (Better, stronger, and faster than parallel port attach ones.)
  • Another run of PCjr bus to ISA adapters so people can experiment with ISA cards on their Jrs.
  • Updated BIOS or a BIOS ROM extension for 3.5" 720K floppy support.
  • An upgrade to a 16450 UART instead of the built in 8250 UART
  • A serial port card that goes in the modem slot
  • An XT or AT keyboard adapter


Jrs are unwanted, low dollar machines - go adopt one today. Save the recreation work for 50 years from now.
Click to expand...

If they're THAT plentiful feel free to ship me one, but I haven't seen for one go for too cheap. :p
 
<rant>

Gee, here is modified system on eBay right now: 250621775862

  • 512K
  • Modified floppy controller and an external floppy drive
  • Monitor
  • Printer port
  • PC Compact printer (the relatively uncommon thermal printer designed for the Jr) with paper
  • Three cartridges and other software
  • Probably the original owner ...

Let's see, one day to go and only $20 yet. I've been watching the eBay sales for years, and I have never seen a system go over $150 yet. And most are under $50. (And for $150 you got the extremely rare SCSI controller and hard drive system from PC Enterprises.)

Look people, forgive me for being blunt here, but you've got to put up or shut up ... After years of reading here I'm am amazing at the people who will:

  • Whine about the travesty of others discarding old computers
  • Complain that they can't get what they want for just about free
  • Suggest that the 'community' do something without ever lifting a finger to do something themselves

So here's a challenge .. if this machine sells for under $75 and it doesn't go to somebody here, then nobody has a right to bitch about not getting one anymore.


Mike

</rant>
 
$30 shipping, that's $50 and that's not so cheap. I wasn't trying to "bitch about not getting one", was just saying, they aren't as common as you're making them out to be - not any more common than a 5160 or what-have-you in my experience. I'd toy with one if I got my hands on one for $20-30 locally, but don't personally want one bad enough to pay shipping. If there were a tiny device capable of Tandy and PCjr functionality that would ship for $10 or less and take up much less space, using a standard monitor and such (a big problem for me, as I can't seem to get my hands on a working CGA monitor), I'd consider buying one.

My point is don't dismiss projects and discourage people just because you've got a pile of PCjrs and there are some for sale around - it doesn't mean someone wouldn't rather have a non-proprietary smaller version.
 
Raven said:
My point is don't dismiss projects and discourage people just because you've got a pile of PCjrs and there are some for sale around - it doesn't mean someone wouldn't rather have a non-proprietary smaller version.
Click to expand...


Like I said, I've been watching prices on and off eBay for years. There are at least two people on this forum who have gotten their machines for free, and one of them didn't even pay for shipping. They are out there, and they are cheap - not just in my basement. There are machines on eBay that languish for days and weeks with no bites.

People can do whatever projects they want to do - I'm just pointing out the logical fallacy in recreating something that already exists, and is in plentiful supply. Sorry, but not willing to make a one time investment of $50 to $100 to acquire a machine for your hobby just seems terribly cheap and unrealistic. Wait until you figure out what a round of golf/flying/sailing/<insert hobby here> costs ... In the grand scheme of things $100 for something you want is close to nothing.



Mike
 
Raven said:
If there were a tiny device capable of Tandy and PCjr functionality that would ship for $10 or less and take up much less space, using a standard monitor and such (a big problem for me, as I can't seem to get my hands on a working CGA monitor), I'd consider buying one.

My point is don't dismiss projects and discourage people just because you've got a pile of PCjrs and there are some for sale around - it doesn't mean someone wouldn't rather have a non-proprietary smaller version.
Click to expand...

This is pretty much in line with my way of thinking: a tiny, PC-compatible machine with around a $10-$15 price tag.

The inclusion of classic expansion features like ISA or the jr sidecar buses would make it anything other than tiny (or cheap), unfortunately..

I will agree with Mike Brutman in that USD$100 is on the low side of things as far as hobbies go.


mbbrutman said:
Rainbow ponies for everyone!
Click to expand...
In that case I'll have the one with the shiny silver tail, if you please.. :D


Regards,
Valentin
 
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mbbrutman said:
I'm confused here. Why would anybody want to replicate or recreate a PCjr when so many of them are still available, and they are so undervalued? Many of them that are on eBay at the moment have been there for months. A basic machine never sells for more than $50 ...
Click to expand...

I guess everybody has their own itch to scratch. I for one think it would be interesting and fun from a hobbiest perspective to replicate the unique features of a PcJr/Tandy 1000 in the form of either a complete reimplementation of a PCJr compatibe computer from the ground up, or in the form of add-on cards for common XT clones.

Don't take me wrong: preservation of original hardware is commendable and important, but there's nothing wrong with a little creative tinkering here and there. :)
 
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