Mike's PCjr Page

alanh wrote:Yes, I'm going to order boards within the week. Will take 4+ weeks to arrive after that however. I'll be selling boards, connectors, and pre-programmed PLDs, and the rest of the parts kit ala-cart for at or near cost + shipping. I'm not sure exactly what those figures will be atm. Likley ~25 for boards, ~10 for new connectors, ~15 for pre-programmed PLDs, ~25-30 for rest of the parts kit (1/3 of that the RTC!), 5 for flat rate shipping. Unfortunately that totals up to about $85 for a full board parts minus hard drive. I wish it cost less. But the reality of it is you just can't build something like this in low quantity much cheaper. I'm going to comparison shop some this week and see if I can get a few dollars knocked off the parts kit and boards. Depending on the demand and pricing based on this estimate, I might do something like $100 for an assembled/soldered board tested and shipped.

Of course you also need the shell of an existing side-car. And the connector if you don't want to buy a $10 new one. They cost $10.25 from State and they are the only people left who apparently still have a lot of them.

By all means please put me down for a complete kit. This is great!

I'm finishing up the Rev A changes atm. I've also go a query out to DorkBot PDX on his medium run service. Pricing is competitive and extra flexibility is nice. So the final boards might be grape apes too.

Board order is in to Dorkbot PDX - 20 boards. Likely will take 3 weeks. ~$20 for raw PCB + S&H. I need to work on documentation and pricing information next.

Very cool.

Alan / Mike, can you re-cap the specs?

IDE adapter
512k RAM - how fast?
RTC

right?

Memory mapped IDE interface
1 MB RAM (only 657.5 usable atm - see below)
512 KB Flash ROM (16 for BIOS / 496 for future ROM disk / cartridge image storage)
RTC
And only for debugging (requires case off), POST display and CPU heartbeat monitor


So far I've been populating the two RAM sockets with 512KB parts. The lower memory is filled to 736 KB (+608KB). However the sidecar bus is gated off by the MB on access to the cartridge ROM areas (D0000 - EFFFFF) - which prevents use of UMB in those regions without taking a soldering iron to a decode ROM on the MB. The option ROM BIOS area (C0000 - CFFFF) could be RAM filled (minus the 16KB card BIOS itself) for +48 KB of UMB. Not sure how desirable that is. Currently IDE BIOS scratch RAM (1.5K) is stored in the ROM window as well. If we nixed the idea of UMB and separate scratch RAM (stealing 1 KB from 768 KB base), we could drop to a 128KB pin compatible part and save a few dollars. Not sure how to go on this one.

A few dollars could also be saved on swaping to a lower capacity pin-compatible flash part. However I like the idea of eventually adding a resident ROM disk for DOS, cartridge images, or both to the boot menu.

Both changes are purely bill of materials. And both could be easily detected in software.

I thought of a nice trick for getting the AMP connectors onto the card without resorting to a hammer. ; - 0

Two large C clamps work nicely. A small piece of metal across the empty plastic box on the one side would help to spread the force a little more. The idea is to slowly use the clamps to force the connector together. It works much better than the hammer and wood technique that I was using before.

Now we just need another source for the connectors. State couldn't fulfill my order - they've lost their stash in the warehouse somewhere. It might turn up, but until then we are stuck scavenging from existing cards.


Mike

My Zip drive is starting to show its age, and it's becoming a little erratic... I could buy another one on Ebay, or holdout for the IDE card. Is there a possibility the card will be available within the next 3-4 weeks by any chance? The only use I have for the Zip is as a pseudo-hard drive for my Jr...

3-4 weeks? Most likely. I'm expecting 20 PCBs any day now.

Great! I'll wait then

PCBs came in except the order was 8 short. I have 12 bare boards and Laen is looking into where the other 8 went.

I just have not had anytime to work on this at all. I need to get some form of documentation up. And there really isn't much of a BIOS for them yet aside from some basic test code supplied by Jeff. I promise to work on this during the week to try and get things into a distributable status by next weekend. Sorry for the delays.