First impressions: THEA500 Mini

▼ On friday, I received my preordered THEA500 Mini. This is smaller and modern version of the Commodore Amiga 500 computer from 1987. By the same company that makes a similar version of the Commodore 64.

After exploring the A500 Mini for a few days, I can't really make up my mind on whether I like it, or it's too limited. So here some first impressions, I'll probably do a more complete review later.

The hardware

The hardware looks really nice, and is quite small. The C64 Mini was right about half the size of an actual C64, but the A500 Mini is more like 44% the size of an Amiga 500. The included mouse is fine but not great, the included gamepad is a departure from the joysticks we used with the Amiga back in the day, but so far I'm not hating it and having the extra buttons is sometimes useful. You can also use the THEC64 joysticks, but a different one didn't work.

The A500 Mini is 130 euros with 25 games included, compared to the C64 Mini at 80 euros and 64 games included. Could they have made the A500 Mini a bit cheaper by leaving out the mouse? Most of the games don't use the mouse, most people will already have a USB mouse and they could of course sell an appropriate mouse separately.

The included games

Unlike the C64 Mini, which has my all-time favorite game Boulder Dash included, the A500 Mini doesn't come with any games that I really played in the past. Sure, I played Stunt Car Racer sometimes, but I wasn't any good at it. (In that regard, nothing has changed.)

The point of the A500 Mini is to play games, so the quality of the included games is important. I guess that means I'll have to give all 25 a try! However, so far I'm having some trouble figuring out how to play the games, as this is often not obvious and there is no documentation on the included games, just an overview of the button mapping on the gamepad, mouse or joystick.

WHDLoad

If you want to go beyond the included games, you can load additional ones with WHDLoad. I had quite mixed success with that: some load quickly and run without trouble, for others Amiberry fires up to set up a bunch of things and then the game never starts.

The problem with WHDLoad is that regular users can't make existing software run under it; you'll have to wait for people with the right skills to create a WHDLoad "slave". This severely limits what you can do with the A500 Mini. It would be so much better if we could also run software off of ADF disk images. (However, WHDLoad is the better option for most games.)

So at this point I'm frustrated by being limited to WHDLoad images, and then having a good number of those not work with no clues on how to solve the issue. However, with such an obvious target, it's very like the Amiga community will make sure as much Amiga software as possible will run under the A500 Mini's flavor of WHDLoad. I've already seen a few examples of this in Youtube videos, but nothing I could try myself just yet.

So more later.

Permalink - posted 2022-04-10

The Battle Royale: benchmarking old computers

▼ On his Youtube channel, Matt Heffernan has a series of 8-bit Battle Royale videos to see which 8-bit computer is fastest. For this, he uses a simple program to calculate the world's lowest resolution mandelbrot set. Still, the Commodore 64 and ZX Spectrum take minutes to do this in BASIC. It's much faster in assembly.

(Aside: I do believe the Z80 CPU has some advantages over the 6502 due to all the arithmetic. I'd expect in a sort test like the one I did some time ago, the 6502 would do better relative to the Z80. I'd probably stick to just the insertion sort, as it's so simple to implement: something like 20 lines of BASIC should do it. The prime calculation test that I used to see which programming language is fastest is even shorter and simpler, but again math-heavy.)

Watching the videos, I started wondering how 16 or 32 bit computers like the Amiga would perform. Or even the C64 with a C version of the same program. So I made a C version, taking advantage of the fact that you can change text colors with ANSI escape codes, so no need to work with real graphics.

Just like the BASIC version, the initial version of the C code used floating point math. I added an 8.8-bit fixed point version to match the 6502 and Z80 assembly versions, but I'm not sure if I got that completely right as the output looks noticeably different.

This is the code. I compiled two Amiga versions that use the ixemul.library: floating point and fixed point as well as a version that doesn't require ixemul.library. That last one won't report its run time, so it's less useful on very fast systems where a stopwatch won't provide accurate results.

On my Amiga 1200 with its 50 MHz 68060 accelerator, the floating point version runs in 0.74 seconds and the fixed point version in 0.64 seconds. With the accelerator disabled so using the stock 14 MHz 68EC020 and just chip RAM, it's 4.4 and 2.04 seconds, respectively. On my Amiga 3000 with its 25 MHz 68030 the results are 2.12 and 1.4 seconds.

If you try this on any other machines, I'd love to hear your results. I'm especially interested in results from 7 MHz 68000 Amigas and the C64.

Permalink - posted 2022-03-29