Why are hobbyist 21st century 8-bit computers so constrained?

[liam_on_linux]

I learned about a new DIY machine to me, the Cody Computer. 

It looks kind of fun, but once again, it does make me wonder why it’s so constrained. Extremely low-res graphics, for instance. TBH I would have sneered at this for being low-end when I was about 13 years old. (Shortly before I got my first computer, a 48K ZX Spectrum.)

Why isn’t anyone trying to make an easy home-build high-end eight-bit? Something that really pushes the envelope right out there – the sort of dream machine I wanted by about the middle of the 1980s.

In 1987 I owned an Amstrad PCW9512:

• 4MHz Z80A
• 512 kB RAM, so 64kB CP/M 3 TPA plus something over 400kB RAMdisc as drive M:
• 720 x 256 monochrome screen resolution, 90 x 30 characters in text mode

Later in 1989 I bought an MGT SAM Coupé:

• 6MHz Z80B
• 256 kB RAM
• 256 x 192 or 512 x 192 graphics, with 1/2/4 bits per pixel

Both had graphics easily outdone by the MSX 2 and later Z80 machines, but those had a dedicated GPU. That might be a reach but then given the limits of a 64 kB memory map, maybe a good one.

Another aspirational machine was the BBC Micro: a expandable, modular OS called MOS; an excellent BASIC, BBC BASIC, with structured flow, named procedures, with local variables, enabling recursive programming, and inline assembly language so if you graduated to machine-code you could just enter and edit it in the BASIC line editor. (Which was weird, but powerful – for instance, 2 independent cursors, one source and one destination, eliminating the whole “clipboard” concept.) Resolution-independent graphics, and graphics modes that cheerfully used most of the RAM, leaving exploitation as an exercise for the developer. Which they rose to magnificently.

The BBC Micro supported dual processors over the Tube interface, so one 6502 could run the OS, the DOS, and the framebuffer, using most of its 64 kB, and Hi-BASIC could run on the 2nd 6502 (or Z80!) processor, therefore having most of 64 kB to itself.

In a 21st century 8-bit, I want something that comfortably exceeds a 1980s 8-bit, let alone a 1990s 8-bit.

(And yes, there were new 8-bit machines in the 1990s, such as the Amstrad CPC Plus range, or MSX Turbo R.)

So my wish list would include…

• At least 80-column legible text, ideally more. We can forget analog TVs and CRT limitations now. Aim to exceed VGA resolutions. 256 colours in some low resolutions but a high mono resolution is handy too.
• Lots of RAM with some bank-switching mechanism, plus mechanisms to make this useful to BASIC programmers not just machine code developers. A RAMdisc is easy. Beta BASIC on the ZX Spectrum 128 lets BASIC declare arrays kept in the RAMdisc, so while a BASIC program is limited to under 30 kB of RAM, it can manipulate 100-odd kB of data in arrays. That’s a simple, clever hack.
• A really world-class BASIC with structured programming support.
• A fast processor (double-digit megahertz doesn’t seem too much to ask).
• Some provision for 3rd party OSes. There are some impressive ones out there now, such as SymbOS, Contiki, and Fuzix. GEOS is open source now, too.

Comments

[blackmetalbuddha]

If you're looking for something that ticks off most of your wishlist, I'd say check out the ZX Spectrum Next.

It’s got modern graphics with up to 256 colors and high-res modes, with screen resolutions up to 640x256. Plus, you get hardware sprites, layers, and scrolling.

For memory, it has up to 2 MB, with bank-switching options, and you can easily work with large data in BASIC — kind of like how the ZX Spectrum 128 did with RAMdiscs.

The NextBASIC environment is actually really solid if you’re into structured programming. It’s a big step up from the original ZX Spectrum BASIC. As for speed, the top CPU speed is 14 MHz in turbo mode, which is much faster than the original.

It also supports SymbOS, so you can run something more like a modern OS if that’s what you’re into. It’s definitely a good balance between retro nostalgia and some of the stuff we expect from modern machines.

[liam_on_linux]

If you're looking for something that ticks off most of your wishlist, I'd say check out the ZX Spectrum Next.

Thanks for this!

In fact, I do have one. It's sitting right next to me at this second.

The snags for me are that NextBasic is rather weird and nonstandard, and classic Spectrum languages like BetaBasic can't access the new hardware.

I sort of wish they'd taken, say, SE BASIC or something and worked with that, rather than strange enhancements to Sinclair BASIC. A clean break and a cleaner language.