fentonc

7 ms·

31.
by fentonc 5y ago
Thanks - I'm looking forward to going back to commuting someday, so I can actually use it!
32.
by fentonc 5y ago
Turbo Pascal also supports overlays, which allows you to chunk up your code and swap it into memory. I genuinely enjoy using the Turbo Pascal IDE on either my 1984 Kaypro or the monster 16-core “Zedripper” Z80 laptop I built. It’s great!
33.
by fentonc 5y ago
I had a much more recent update in this now decade-long adventure: http://www.chrisfenton.com/digital-archaeology-part-2/ Although this one was a lot less work than the first attempt. My original 1/10-scale Cray-1
34.
by fentonc 5y ago
It's as awesome as you imagine: http://www.chrisfenton.com/the-zedripper-part-1/
35.
by fentonc 5y ago
What type of Kintex-7 part were you thinking? This is a little more svelte than my 16-core Z80 "ZedRipper": http://www.chrisfenton.com/the-zedripper-part-1/
36.
by fentonc 6y ago
I’ve done it, and it’s great! http://www.chrisfenton.com/the-zedripper-part-1/
37.
by fentonc 6y ago
I made one of these about 8 years ago! https://www.thingiverse.com/thing:113044 Although theirs is a much better execution =)
38.
by fentonc 6y ago
I use Kermit 4.11, which is readily available and works fine with a Wifi232 (or a normal serial cable + null modem adapter) at up to 19.2 kbps. Turbo Pascal is super fun!
39.
by fentonc 6y ago
The '84 model Kaypros are surprisingly fun to write games for: http://www.chrisfenton.com/dd9-kaypro-edition/
40.
by fentonc 6y ago
I have a machine of similar vintage (A Kaypro 2/84), and I would highly recommend getting a copy of Turbo Pascal 3 to play around with. It looks like the Osborne has 4KB of video RAM - I bet you could make some fun demos for it. I mana
41.
by fentonc 6y ago
I agree! I'm a computer architect, and I love playing around with FPGAs for doing 'fantasy architecture' projects (like a 16-core Z80 laptop, or a USB adapter for an old nCube supercomputer). A modern FPGA is like being able
42.
by fentonc 6y ago
The actual logic requirements are pretty minimal (~1000 LUTs, maybe?), so it mostly depends on what kind of memory hierarchy you want. The ZedRipper relies entirely on internal BlockRAMs, which are a much more precious resource - I think I&
43.
by fentonc 6y ago
Oops, changed to 'horde'! The distinction is mostly architectural, in that the 'horde' is composed of an undifferentiated mass of CPUs (currently 8, could probably be expanded up to 128 with a cache-based memory hierarch
44.
by fentonc 6y ago
I have a real Kaypro 2 computer with a 4MHz Z80 in it, which I also use Turbo Pascal on - on the Kaypro, it's perfectly usable, but you get used to waiting a few seconds when you're loading files, compiling, etc. On the ZedRipper,
45.
by fentonc 6y ago
That's an interesting question that I haven't explored much - the network on the ZedRipper is a unidirectional synchronous ring operating at the full 140 MHz, with a round-trip latency of ~32 clocks or so, but the interface expose
46.
by fentonc 6y ago
Thanks! The actual logic required for the Z80 core is tiny - you could probably make a dual-core version with something like this: https://www.tindie.com/products/tinyvision_ai/upduino-v30-lo... FPGAs are super fu
47.
by fentonc 6y ago
If anyone's got questions about my extensive upgrades to the world's least useful laptop, fire away
48.
by fentonc 6y ago
Lol - the 'overkill' approach was mostly one of expediency, since I had spent most of the summer I had to work on this project just trying to get my hands on the disk drive and then powering it on without blowing a fuse. I only ha
49.
by fentonc 6y ago
The Cray vector processors had a set of 8 64-element x 64-bit 'vector' (V) registers, as well as 8 64-bit 'scalar' (S) and 8 24-bit 'address' (A) registers - so it would sort of be similar to 4096-bit wide SIMD
50.
by fentonc 6y ago
All of the early Cray mainframes (even the Cray-1 discussed here, although maybe only the somewhat later Cray-1/S) supported a "Solid State Disk" peripheral, which was basically a refrigerator full of RAM that was accessible
51.
by fentonc 6y ago
To create the 'programmable filament,' you only switch over to each color once as they generate the toolpath in such a way that the nozzle doesn't interfere with previously printed filament (and the printer resets the z-axis
52.
by fentonc 6y ago
A friend of mine wrote a simple program to try to evaluate the Collatz Conjecture on my electromechanical computer! http://www.chrisfenton.com/the-numbotron/
53.
by fentonc 7y ago
As a skill, I think it’s just called “engineering in a competitive market.” Anything you can do to make your chip more attractive to customers is a win, so designers go to great lengths to do so. Things like caches, pipelining, branch predi
54.
by fentonc 7y ago
I happen to be a computer architect both professionally and as a hobbyist, but the basics of it really aren't that complicated. All of the _hard_ parts are people being terribly clever to eek out the last bit of performance in a given
55.
by fentonc 7y ago
That's great! The idea of a cluster with a wireless interconnect is hilarious to me for some reason.
56.
by fentonc 7y ago
It's current manifestation is very much a 'good enough' solution. I just wanted a scheme for simple all-to-all connectivity to map the serial ports to, and the only traffic it carries at the moment is either terminal traffic
57.
by fentonc 7y ago
I love all of the weird computers that got built by academics in the 1980s! That sounds like such a cool machine.
58.
by fentonc 7y ago
Yeah, if you just replaced the 64KB of RAM with a 4KB cache backed by DRAM, you could probably fit 64 cores in one of those no problem, but 1) the performance wouldn't be quite as good, and 2) this project was mostly an exercise in exc
59.
by fentonc 7y ago
I had never heard of that machine until I posted this and someone sent me a link to it. The architecture of the ZedRipper is actually incredibly similar - each CPU has its own dedicated 64KB of memory and then an I/O mapped high-speed
60.
by fentonc 7y ago
I misremembered, I think the CTSS source was actually written in a language called LRLTRAN. I just remembered it was something obscure.

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