In my last post, I mentioned that I had rearranged my basement computer room to make room for a new addition to the Byte Cellar. Well, my latest acquisition finally arrived: a TRS-80 Model 4, my first Tandy / Radio Shack computer.

My first memories of the Model 4 are from way back in the summer of ’83. There was a Radio Shack in the mall my mom used to frequently drag me to when I was but an 11 year old geek. This one day, this particular Radio Shack had setup a computer display in front of the store, out in the mall. I sat down at a Model III and fiddled with it a bit. I was using a TI-99/4A at the time and recall really liking that Model III. I asked the woman running the display all about it. She mentioned that the Model 4 was about to be released and that, if I was going to jump, it would be better to wait. Well, I wasn’t about to jump on anything, but it was the first time I’d heard mention of the Model 4.

A big part of why I wanted that TRS-80 is because its form-factor always, to me, represented the image of just what a computer should look like. Its design is perfect, for what it is — screen, drives, keyboard all in just the right place. I wanted to sit in its presence and feel its keyboard and bask in the glow of its 12-inch monochrome CRT. So I bid and won the eBay auction and in the mail it went. And that’s where the adventure began.

This unit was shipped to me by way of the U.S. Postal Service. I’ve often said that J. R. R. Tolkien’s immortal classic The Lord of the Rings could have been a lot shorter if it had simply been decided at the council of Elrond that the ring would be shipped to Morder by way of the USPS. There is no question that it would have been utterly destroyed. So, as you may have guessed, damage ensued.

Upon initial power-up, I discovered two problems: several keys were not registering and the system was not recognizing its floppy drives. Upon opening the case, the cause of the problems were quickly apparent. Jostling during shipping caused the floppy drive controller’s power cable to come loose. Quickly remedied. A look at the bottom of the keyboard, however, revealed a more complex problem. It seems that somewhere along the line a postal worker dropped the package from the top of a mail truck…or something like the same; something caused the TRSDOS document binders to impact the keyboard hard enough to thrust the mid-keyboard support peg through the keyboard’s PCB. It wasn’t pretty. Happily, soldering three bridge lines to the proper key contacts got the keyboard back in working order.

As regular readers will have already guessed, the first thing I did was to set up the Model 4 as a text terminal to my Mac Pro. Omniterm Plus, a hand-made null modem cable and a few magic words in the OS X terminal was all it took. Using vintage machines in this way gives me such a great excuse to finger their keyboards regularly. Some people are serial killers — I’m a serial terminaler, it seems, as this is my fourth such project (one, two, three).

That said, moving through the various TRSDOS and CP/M apps I’ve got on hand is most interesting. I’m expecting to have much fun with this machine in the coming months.

Have a look at my photo gallery as well as the “TRS-80 Love” Flickr group I setup.

Let me first say “no.” I am not in the process of transforming this retro computing blog of mine into Byte Cellar: All Things As Mac OS X Dumb Terminals. Honest!

But yes, I do seem to suffer from a woeful addiction. I admit it to you, my readers. (I can feel a weight lifted already.) And the undeniable evidence of this addiction? I’ve wired up yet another vintage system as a dumb terminal to Mac OS X. Hey — third time’s the charm, right?

First, a bit about the vintage system in question. Both of my regular readers may recall that about six months ago I was intrigued by what I heard of Earl Evans’ interest in and restoration efforts concerning one of the first laptop computers, the Epson PX-8 “Geneva” (circa 1984), on his Retrobits podcast. I remembered the unit well thanks to a review I read of it back in 1984 in an issue of Computers & Electronics magazine. In fact, I still had the magazine on hand so I dug it out and scanned in the review, along with a nice two-page Epson PX-8 advertisement. I was pleased to hear back from Earl who rather enjoyed having the review to read and let me know that new-in-box PX-8s were still available for purchase from Star Technology! And, of course, I did.

The PX-8 is a great little machine. It weighs 5 lbs, features an 80-character by 8-line LCD display with angle adjustment, is powered by a Z-80 compatible CMOS CPU, runs CP/M 2.2 out of ROM and runs for 15 hours per charge. It comes with several extremely basic apps on-board (including BASIC, actually), and additional programs can be added by way of pop-in ROM chips or via floppy, if you’re fortunate enough to have gotten your hands on an elusive FP-10 floppy drive. Epson sold the PX-8 for $999 back in its day.

I brought the unit in to the office some time ago to fiddle with occasionally during free time at lunch. I noticed it sitting there the other day, next to my Apple //c which acts as a dumb terminal tied to my MacBook Pro when it occurred to me that I had an oldschool Mac mini-DIN 8 serial cable tucked in a drawer here…and that the PX-8’s RS-232C port is likewise a mini-DIN 8…. After a few minutes of hunting down pinouts on the web and sketching out a crude null-modem signal mapping by hand I pulled out the Swiss Army knife and started stripping cable. I was at work and had no soldering iron on-hand, so it was twist, twist, twist and time to cross the fingers. I connected the PX-8 to my USB-to-serial converter, opened an 80×8 terminal window in Mac OS X, issued the magic commands and voila!

It’s not a particularly ideal terminal — I don’t believe the system’s terminal app is even VT-52 compliant. Like the eMate 300 I put through the same drill, I don’t picture the PX-8 being a permanent fixture in the office. But hey, it was a fun way to spend lunch!

I hope you enjoy the photos.