Lee Hart's 1802-Based Mini-Microcomputer: The Membership Card.
Retrocomputing in Your Pocket.
Lee Hart's Membership Card computer. It's based on the RCA 1802 microprocessor, and it's a close cousin to the COSMAC Elf computer (Google it, if you don't know about it!)
Meanwhile, I'm trying to fit my Membership Card into its tin. I think my switches are too tall, so I'm going to have to make some other accomodations.
The tin doesn't quite close up. My interconnect between the PCBs may be too tall, or my switches aren't laying as low as Lee's did. It's only about 1.5mm, but it's enough. I'm working on Plan B now.
My 8085 Handheld Single Board Computer Project
My first shot at a front panel layout for my 8085 computer, laid out on acrylic sheet to make it easy to see what's where.
Each step of the project adds just one to three new pieces to the computer. The complete computer is only twelve integrated circuits, plus resistors, capacitors, and other small parts. It can be built with only eight ICs, if you want a simpler version that gives up a couple of extras. These can always be added in later, if desired. The real key to the project is that it provides a complete, functional 8085 system similar to the SDK-85 development system that can be built up from simple parts that are easy to understand and use in programs.
Most of my work lately, other than playing with software and deciding how I want the programmer's interface to work in its operating system, has been on the front panel of the computer and its enclosure. I want it to be something that someone with minimal tools, and even without power tools, can build from common materials available at an ordinary hardware store. I also want it to be attractive enough to show off after it's built, not something that looks like it belongs in a junkpile.
The partially-complete Masonite face panel of my 8085 computer.
Since posting details on the 8085 construction project takes about 3 times as long as doing it, I've been holding off on doing an update of the project on its site until I have the enclosure complete. Now I'm almost done, so an update will probably occupy the later part of my summer.
Ampro Little Board Plus Z-80
My Ampro Little Board Plus, in its original incarnation. A pile of parts on a kitchen table.
I got a pair of system boards for these from Dave Baldwin when he was cleaning out some old computers prior to a move. One night, I really wanted to get one of the many systems up and running that Dave had given me, and since these seemed like they'd be the easiest to get running I grabbed one and got it going.
A complete computer, with Z-80 CPU at 4MHz, Floppy Disk Drive Controller, Serial and Parallel I/O, and SCSI all on one small card--in 1984!
Honey, how about we eat dinner on the patio tonight?
Then Vic Maris of StellarVue Telescopes offered me an old desk he didn't need at his offices any more. He said it was large. It is. I had to do some major work to get it into my office. But once there, I put my usual computers on it (an iMac 20" and a Beige G3 PowerPC Mac), and had enough room for one more computer!
My new desk, with Three full size computers.
I put the Ampro's current box (a PC's beige box) under the desk. I've got another enclosure for it that'll be much more attractive and interesting--but that's another project yet to come. On top, I had plenty of room for my ADDS 2020 terminal, which is the user interface for the Ampro. Unlike the original Big Board computer (the "Ferguson"), the Ampro uses a terminal, whereas the Big Board has a built in CRT and keyboard interface.
Once I got everything in place, I started working with my ADDS terminal to try to get the best image out of it. I originally used this terminal with the Ampro because it's the smallest full terminal I've got. I took a look at all the space on my new desk, and realized...I could use a better terminal. So I pulled out my VT-102, which has a very nice white on black character display and is very sharp.
The Beige G3 runs Lemmings and Warcraft, the iMac is my interwebs machine, it's desktop background is an image of the Big Board computer PCB, and to the right is my Ampro's terminal, here showing the utilities menu.
The VT-102 wasn't perfect, though. So, thanks to some help from fellow retrocomputerists I was able to find the technical info I needed to adjust the character height on the display (it was a little taller in one part than another when it came out of the garage.) Now it's perfect.
Now I'm happily writing games in Turbo Pascal at my desk, and the space next to my easy chair is waiting for another project to move in while my wife's back is turned.
Getting the new desk in meant moving some stuff out.
Since this picture was taken I've cleaned up. Really.
The breadboard version of my 8085 computer, the MAG-85 is still in use, by the way. That's where I've been doing my OS development while I finish the permanent version of the hardware. That way I don't have to worry if I've got the permanent one's keyboard and display off for work on the face panel if I want to sit down and code some 8080/8085 assembly.