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Monday, March 15, 2021

TRS-80 emulator

Let's go back to the days of Starsky & Hutch and Asteroids!

Most people might think it's pretty stupid to emulate a retro computer using a retro computer? Thankfully, not me because I've found something rather incredible called 2nd Life. It's a TRS-80 Model III emulator by Sander Berents and is something I stumbled on purely by chance so figured I should give it a playtest.

Now, I've never actually used a TRS-80 so I imagine not many made it outside of the US? Anyhow, Tandy and RadioShack released the first model in 1977 and it was a huge hit for those wealthy enough to have lots of spare cash. Back then, I would have been six years old and too young to care about something like this :-)

It's sadly-impressive that something this good was released when most of us had left the Atari world!

What's a RadioShack?

Like you, I love my Atari ST, even when it pretends to be something else, be that a Sinclair, Commodore or even a peculiar clunk of hardware by RadioShack (I used to love the Tandy stores). Anyhow, a TRS-80 emulator sounded far too tempting not to boot up so I read the docs and hit the web to learn how to operate this ancient beast.

First things first, do read the docs and take a look at the FAQ text file to understand which options to enable/disable for the best performance and compatibility settings. You will also find two more disk images with compiled and BASIC games but you'll be best with a 16MHz computer to enjoy something close to native speeds.

2nd Life requires ST High resolution and is very easy to use. Along the bottom of the screen, are four floppy disk drive icons - click to highlight Drive 0 and use that as the TRS operating system boot drive. The second drive icon can be used for anything like games or other images that you may have downloaded from the net.

One of the first things I booted up was Donkey Kong. Okay, it looks terrible but plays well.

Old but not that much different...

Using the TRS-80's DOS commands feels a little quirky but is fairly easy to learn. For example, DIR will display the directory of a disk and it can be expanded with extra options and filters, as you'll see in the video:

DIR 0 - will produce the contents of Drive 0
DIR 1 - will produce the contents of Drive 1. Easy, right?
DIR 1,/BAS - this displays the same list but filters for BAS files.
CAT 1 - this provides an alternative way to load programs!

We're gonna get a little more complex now but it's worth it to watch the dancing alien:


The command looks worse than it actually is. Breaking it down, this simply instructs the computer to load up the BASIC program. Then that will load/run the file "DANCING/BAS" which is stored on Drive 1. Easy!

Sea Dragon is a terrible mess of ZX81 blockiness but it is a brilliant shoot 'em up!

Get to the games already!

Ultimately, we're here to play some TRS-80 games and I gotta tip my hat to this old piece of 70s kit. There are some great games in its library and there's a good reason I chose Sea Dragon as the video thumbnail. Like any old computer, there's a wealth of vintage games from the era: Pacman, Invaders, Frogger, and so on. I'm a geek, so I enjoyed the thrill of playing with something that's almost as old as me. No rude comments, please!

Performance-wise, the humble 8MHZ Atari ST will successfully emulate and run everything you throw at it. However, it's going to struggle with the games as it's simply not fast enough. Personally, my Mega STe is the basic and minimum requirement and produces near-perfect speeds, generally speaking. So, 8MHz will be fine but 16MHz will get you gaming. Hardly a shock and just the same as with other emulators we have within our library...

Don't forget to read the docs as README.TXT is there for a reason... Okay, I'll nag no more!

Yes, this really is Frogger. Hopper has awful collision detection but is a pretty good game.

Games! Give me games!

One of the best games I played was Sea Dragon, which is a fantastic scramble through watery canyons. Sadly, I wasn't impressed with Penetrator that struggled with jerky graphics and twitchy controls. It was a shock to see a chunky version of Donkey Kong with huge black and white blocks but the gameplay is superb and that's what matters. However, the blocks worked great for Armored Patrol and the wealth of PacMan games!

There are a few games bundled with 2nd Life and many are great but sooner or later you will want more. Thankfully, there are some great websites with disk images stuffed full of games and I managed to find racers, lots of different Space Invaders, Zork and even Temple of Apshai - which is nothing at all like the Atari ST version and its "turn-based" element caught me off-guard, in a nice way. But boy, is it slow - even on a real TRS-80. Yikes!

Most (all?) disk images found on the internet won't be compatible with the Atari ST. Thankfully, Sander has a utility to convert these for 2nd Life and it works a treat from what I've seen so far. Hence, how I got to play Hamburger Sam, Berserk, erm Robot Attack and the sluggish Temple of Apshai.

He might not be yellow but he's on the TRS-80 as Gobbler!

The CryptO'pinion?

I initially expected the TRS-80 to be nothing more than a cumbersome piece of ancient hardware that I wouldn't particularly enjoy. I couldn't be more wrong, this is a machine that appears to have more power and versatility than I would ever imagine. It's a great computer and it's no wonder those plucky Americans snapped it up!

2nd Life is an equally fantastic piece of software and I'm impressed how well it runs in terms of its speed and compatibility. The inclusion of a utility to convert disk images into a format that 2nd Life can recognise is a wonderful addition and opens up the possibility of playing everything there is. Techies can go further: font editor, altering the keyboard layout, linking computers via parallel ports and even tinker with a disassembler debugger...

The TRS-80 is a great machine and it is so impressive to see the Atari ST flip back in time so easily and reliably. This is a fantastic emulator - however - you will need a >16Mhz computer to start gaming like its 1977 and my Mega STe felt close to the speed of a real TRS-80 (from what I've seen online). I have really enjoyed using 2nd Life and I'd love to hear what hardware and performance you guys are getting, so let me know in the comments below.

GitHub has the download which includes the source code for those uber-geeks amongst us :-)


Look what I found and it's quite different to the Atari ST game. Quick, kill the Ant Man!!

This is Astro and it's a BASIC game. No, I mean it's written in BASIC and it's good.

Hamburger Sam, based on BurgerTime but felt more like Mr Wimpy to me. Love it.

This is Speedway and it's kinda like an early Spy Hunter or Major Motion. Hmm...

Runner demands quick control action - you'll regret not reading the FAQ text file!

I only ever played Penetrator on the ZX Spectrum... and this isn't as good!

Hang on, is that Berserk? No, it's Robot Attack and completely different. Honest.

Limit Zero is absolutely superb and something you should play!!

ScarfMan? Okay, it's getting silly now...

Lunar Lander is a cracking conversion but too slow for an 8MHz ST to handle.


  1. Thanks for the great review! I bought a 520ST soon after it launched. It turned out to be a lemon that broke down every three months, and I replaced it with a 1040ST two years later. 2nd Life was the last application I wrote on it. Unless they have hardware issues, I tend to use my computers for a long time, as I type this on a 2013 MacBook Pro :-). Before the ST I obviously owned a TRS-80 Model III, which although primitive compared to later machines like the C64, was a great reliable machine. Initially with 16KB RAM and cassette tapes, and later with 3 disk drives, 48RAM and a daisy wheel printer, it was a wonderful machine to code for. "Speedway" is actually a clone of the 1978 Philips Videopac "Race" I wrote many years later. I still have the ST and the Model III, but haven't turned them on since.

    The emulator consists of around 10,000 lines of 68000 assembler for Z-80 and disk controller emulation, and several thousand lines of C code for the GEM shell.

    One of my more recent applications is for macOS. It's called "Observatory", and you can find it in the Mac App Store.

    1. It's superb that you have seen this!! :)
      Marvellous emulator and I really enjoyed tinkering with something I never used before. The computer is actually really good all things considered. Thanks for popping by :)