Progress on Loading FLEX from SD Card

Thursday, October 16th, 2014

…and other stuff.

I’ve got Michael Evenson’s SWTPC emulator up and running, so now I’m slowly working from the top down (writing FLEX drivers) and the bottom up (drivers in EPROM to do SD disk reads/writes).  More and more of the disk logic is going into EPROM as it’s being properly tested and debugged.  Maybe by next weekend I’ll have something running.  The actual board hasn’t been designed yet but it’ll be easy to lay it out once the software is working.

The other big project is my son’s Eagle Scout project in a couple weeks, so that is high priority for now and consumes a fair amount of time.

I’ve also been using the 3D printer a lot more recently.  There are some vintage computer pieces that just aren’t made anymore and hopefully I can fabricate them myself.


Real SWTPC Memory Board

Friday, September 26th, 2014

For fun, I put a real MP-8M memory board into our test motherboard and ran memory tests:


You can see the power supply above the board in the background… 1.03 amps!  That’s with only 4K populated, versus our 64K board that draws about 100 ma.

Memory tests ran for a couple hours without a hitch, so this shows our CPU and motherboard will work properly with vintage boards.


Fun at VCF MW 9.0

Saturday, September 20th, 2014

I took a lot of photos, but these are a few of the more interesting exhibits, in my opinion.

The Corsham Tech display of a 6800 CPU system (left) and a KIM-1 with our expander boards:


A few of my Franklin Computer systems.  A CX portable and the lowest numbered ACE-100 found so far:


Jack Rubin’s PDP-8.  I gave him a USB thumb drive and joked that I loaded it with the latest PDP-8 malware I could find, but didn’t see where to plug the USB drive in.  He removed the covered an showed me that he has a USB interface in his PDP-8!


There’s always at least one PDP-11 at every VCF:


And a VAX 11/780 stood guard by the door into the exhibit area:


For some reason I never took a picture of the Alphas right next to me.  Someone had some DECstations for sale but I didn’t ask for prices.

There was an impressive collection of 1802 machines as well:





I had a fun time out in Lombard, IL at VCF MW and will probably go again next year.  I keep telling people it was like the old days at the Trenton Computer Fest where lots of smart people gathered, exchanged ideas, showed off what they had, discussed future plans, and everyone was willing to help each other.  There were people with soldering irons turned on, scopes, logic analyzers, collections of tools and other things needed if someone wanted to try building or repairing something,

It was definitely a fun weekend.