Last week I once again braved the streets of San Francisco to pick up an interesting bit of retrocomputing hardware - a Tandy Color Computer (CoCo) 3 for $20.
The lot came complete with a CoCo 3 console internally upgraded to 512K, a CRC Computers Inc. Disto Mini Controller 1 floppy interface, an external drive box with a 5.25” diskette drive, joystick, Metric Industries Model 104 serial/parallel interface, several ROM cartridges, diskettes and books.
I’ve never owned a CoCo personally, but I did have a lot of fun playing around with my uncle’s CoCo 2 system back in the eighties. Booting the machine evoked fond memories of keying in programs out of computer magazines and saving them on cassette, which is something I actually enjoyed doing back in the day.
However, I’d never actually used a CoCo with a floppy subsystem before and had to do a bit of Googling to unearth a few needed commands. I became a bit confounded at first, as none of the disk based commands I tried actually seemed to work.
I soon discovered that the switch on the Disto controller toggles between two different BASIC versions, and was initially set to standard Extended Color BASIC. Once the switch was in the correct position, Disk Extended Color BASIC became active and the commands I’d located online actually worked.
My attempts to boot Flight Simulator II still met with failure. Unlike some retro systems, the CoCo 3 does not perform a disk seek (autoboot) on power up - even with Disk BASIC active. So how to boot a piece of commercial software without a standard directory structure (the ‘DIR’ command returned gobbledygook)? Back to Google again, and this time came across a YouTube video of a chap booting up Flight Simulator II on a CoCo 3 emulator (linked below). Thankfully, he’d recorded the entire boot process, including the magic boot command - “DOS”. Once this arcane word of power was entered the drive sprang to life, booted OS-9 and finally Flight Simulator II.
I haven’t done much more with the machine just yet though I did boot up the original Flight Simulator I diskette just to see the difference. One thing I’d like to mess around with a bit is OS-9/NitrOS-9 itself. I actually owned an OS-9 based MM/1 tower about a decade ago, but at the time was less into the retro scene and wound up passing it on without really diving into it. The CoCo is quite interesting in that it’s default OS is a real-time, process-based, multitasking, multi-user, Unix-like operating system.