Coming soon: RISCYFORTH


When I was much younger FORTH fascinated me as an alternative interpreted language for the Z80 eight-bit processor machines I was typically using.

Compared to BASIC – the language that the Sinclair ZX80, ZX81 and Spectrum came with – FORTH was reputedly lightening fast and very powerful.

My brother and I even obtained a tape copy of somebody’s FORTH for the ZX80 and we ran it – and it certainly was fast. But it also lacked the simplicity of BASIC and the tape was soon handed back.

But I’m back on the case again, inspired by this (long out of print but widely available on the web) book – Threaded Interpretive Languages – and by the prospect of a single board RISC-V computer – the BeagleV – coming out this year.

Currently I am targeting the PK proxy kernel on the Spike Risc-V emulator for RISCYFORTH but if and when I get a real BeagleV I’ll immediately switch to that (I applied to be an early user but have heard nothing so while the signs are that the project itself is making good progress it looks like I’ll have to wait to get my hands on one.)

I struggled with getting the mechanics of RISCYFORTH right for a long time but in the last week I’ve finally started to make serious progress and it actually does things (only in immediate mode for now). The picture shows my very first success with a multi-token command line from a couple of evenings ago and it’s come on a fair bit since then.

It’s nowhere near a releasable state but it’s rapidly improving.

Why bother? Well I think it’s important that RISC-V succeeds as a disruptor of what is starting to look like an ARM monopoly and so contributing to the ecosystem of the first single board seriously affordable RISC-V device matters. And, of course, because it’s there.

Always yield to the hands-on imperative (from this classic).

Update: My brother actually thinks we borrowed somebody’s Jupiter Ace which was a Z80-based FORTH computer of a very similar size to a ZX81 – and I think he might be right.

Trying to work out why some people think Kevin Mitnick is a hero


Free Kevin bumper sticker, advocating release ...
Free Kevin bumper sticker, advocating release of Kevin Mitnick (Photo credit: Wikipedia)

For the last six months I have been spending a fair bit of time in the gym – I am getting older and I need to lose weight and increase fitness.

In truth, I quite enjoy it in general, but there are moments when I want to stop just because running on the same spot on a treadmill is essentially not that exciting. And recently I have been upping my endurance and pace (from walking to slow running, that is), and the biggest challenge to keeping that up and extending it can feel like beating the boredom, not passing through any physical barrier.

So, I thought I’d try an audio book as a way of overcoming the running-in-one-spot-blues. The one I wanted –The Idea Factory: Bell Labs and the Great Age of American Innovation – exists but I am banned from buying in the UK (so much for the free market), so I decided to try Ghost In The WiresKevin Mitnick‘s (ghost written) autobiography.

Now, I have listened to about an hour of this and I am really struggling to understand why so many people see Mitnick as a hero. So far he’s only 17 but has already described his engagement in sexual harassment, behaviour which got his mother’s phone cut off and general all-round anti-social unpleasantness.

I am not into lcoking people up and throwing away the key, especially for crimes against property which have minimal impact (after all if you steal a piece of software source code you don’t automatically diminish the utility of the code to the original user). But I think I would find it hard to be angry on Mitnick’s behalf. Perhaps greater injustice will be revealed as the book goes on, but so far Mitnick just sounds like a poorly socialised boor.

No (well, not much) kernel hacking on a Sunday


These days it is possible to host the Linux kernel on GitHub and their tools reveal some interesting things about the pattern of kernel hacking (or at least of kernel committing.)

The “punchcard” tool shows what times commits are made. And here it is for the Linux kernel:

GitHub punchcard for the Linux kernelIt seems that kernel hacking is pretty much a 9 – 5 week-a-day task, though with a bit of extra stuff in the evenings – pretty much what one would expect from a team of office workers.

With more and more additions to the kernel coming straight off git pulls, this pattern must reflect rather more than Linus Torvalds‘ own office habits.

It looks like the image of kernel hackers as nerds pulling all-nighters with the help of “rotary debuggers” (see Hackers: Heroes of the Computer Revolution for more of that) is well past its use-by date: building Linux is just a job.

Breadboard 81


Benkid77 ZX80 Factorial
Image via Wikipedia

Not everything about computing is on the internet.

Sometime around this point thirty years ago my brother and I went to a computer exhibition in London – “Breadboard 81”

There are a couple of references to it findable through Google. But not much.

It was a fantastic experience – but perhaps also the end of an era: the computer that feature most of all was the “UK 101” – a kit based effort with a real keyboard (unlike the ZX80 Conor and I were using).

It is impossible to describe the thrill one could get from being able to see, use and program (in either BASIC or assembler/machine code) any of these devices: everyone was a pioneer and everyone was equal. (Though this book this book captures the feel of the era that was dying even as it peaked.)

Perhaps there are others who will read this who were also there and who can share their memories of this moment… reminding me of where it even was would be a start? Olympia?

Coming up… the lambda calculus


An example of a DFA state diagram
Image via Wikipedia

Another thing that The Annotated Turing taught me is what all those lambdas that I have seen over the last 25 years were about, or at least it introduced me to what they were about.

So I have just ordered a copy of Structure and Interpretation of Computer Programs: and I can guess that some blog posts will eventually follow.

Oh no. Maybe I am turning into a LISP hacker – having finally reached the age that all these guys were when I first became aware of them (older, actually).