My dad bought me one in 1981 or 1982. It set the direction of my life. Today I'm Director of Engineering in a software company.
The ZX81 Turns 40
71–80 of 84 posts
Re: The ZX81 Turns 40
#72Re: The ZX81 Turns 40
#73I loved this computer as a kid. It didn't have hires graphics, but some clever people figured out how to do fake hires graphics by timing tricks. It blew my 10 year old mind. The timing tricks seem to work in this Javascript emulator:
http://www.zx81stuff.org.uk/zx81/jtyone.html?track=RocketMan...
https://retroresolution.com/2015/09/07/rocket-man-sinclair-z...
Re: The ZX81 Turns 40
#74The ZX81 was an amazing machine. Long live the ZX81.
Re: The ZX81 Turns 40
#75If like me you have fond memories of the ZX81 (though not perhaps of the keyboard), then you might find this print interesting: http://www.alisoneldred.com/john-harris/fine-art-prints-1/sc...
How appropriate considering how the ZX81 launched the careers of many software engineers.
Re: The ZX81 Turns 40
#76Earlier quoted context omitted.
0 is actually what I'd expect as an answer. Even on very modern Python you get In [1]: 2.0**64 - (2.0**64-1.0) Out[1]: 0.0 Thats how floats behave like with operands that differ greatly in magnitude. Also this In [2]: 2.0**64 == (2.0**64 - 1.0) Out[2]: True
"1" in Scheme: >(- (expt 2 64) (- (expt 2 64) 1)) 1 http://people.csail.mit.edu/jaffer/SCM.html
Are you sure that isn't just doing integer math? I don't have a scheme implementation handy, but I tried it in sbcl Common Lisp and while
(- (expt 2 64) (- (expt 2 64) 1)) does yield 1,
(- (expt 2.0 64) (- (expt 2.0 64) 1)) yields 0.
Re: The ZX81 Turns 40
#77The father of a (still) very good friend bought one, and granted us access to the incredible binary world when we where 16.
I am 56 and every single $ I have made is based on the experiences I gathered during these endless hours of learning how to code on that machine.
I miss his dad as much as I am grateful.
Re: The ZX81 Turns 40
#78Earlier quoted context omitted.
"1" in Scheme: >(- (expt 2 64) (- (expt 2 64) 1)) 1 http://people.csail.mit.edu/jaffer/SCM.html
Are you sure that isn't just doing integer math? I don't have a scheme implementation handy, but I tried it in sbcl Common Lisp and while (- (expt 2 64) (- (expt 2 64) 1)) does yield 1, (- (expt 2.0 64) (- (expt 2.0 64) 1)) yields 0.
True, 0. But I think Guile had an exact->inexact function.
Re: The ZX81 Turns 40
#79In terms of ROI, the best £69.95 I ever spent (I still have the receipt from WH Smith). It wasn’t the first computer I ever used, but it’s the first one I ever owned at age 9 and it led me down the path that’ll be familiar to many here... I’m glad I still have it, and the Spectrum and Amiga’s that followed. Incredibly, the ZX81 hardware and software scene is still alive. You can get parts for it quite easily, includi…
One of the benefits of designing of almost entirely off the shelf components
Re: The ZX81 Turns 40
#80Earlier quoted context omitted.
Even Blu-Tack for holding on the RAM expansion is still available to buy (sorry, too hard to resist)
Real coders use Velcro ;) [EDIT] actually, the Memotech units shipped with a piece of velcro to eliminate wobble. I think that Memotech kit had a great aesthetic. https://www.nightfallcrew.com/27/09/2013/memotech-memopack-1...
Agreed. They carried it over to their own computers, too.