Sinclair ZX80 / ZX81 / Z88 Forums

This is my boldest attempt: to drive a single printer line.
The Spectrum version simply jumps into the ROM, ZX81, Lambda and J. ACE uses a custom control loop.
I have no idea on whether the printer will like the sync control I deployed because I do not have the real hardware, but I'm very curious..

The attached programs should work on the ZX80, ZX81, ZX Spectrum and TS2068, the program will take very long to run (probably overnight) and should print a 255x255 non zoomed Mandelbrot fractal. If you like this sort of things I can provide a super high resolution of the past "coswave" example, e.g. by rotating the picture and printing, say, 600 or more rows.

The same function includes the standard 8 rows buffer printing, which will permit different column resolutions. Another possible evolution is an HR version of the hardcopy of the text page, obtained by rotating the output and using a 10x10 or 12x10 font (or by just providing slightly taller characters, e.g. 8x10).

Hi Stefano
I printed using a ZX81 and Alphacom printer: I found, that there are "gaps" between the printed lines and thus the image is streched in vertical directiom:


Text hardcopies do not have these gaps (despite my printer does not print exactly squares: characters are slightly streched in vertical direction):



Siggi

Thankyou Siggi, I feared something like that

..but it is still a nice output for a zx81


It is still an interesting result, but it limits the single row drive use; there could be a way to slow down the paper feed, I'll investigate.
The 8 rows buffered printing should behave differently, I'll try to prepare another test program.

.. one more crazy idea for printing row by row. The stretched output can be used to hardcopy in BANNER mode by providing a bigger font and rotating the output

I just discovered the Seikosha GP50S manual, it suggests an interesting way to get the graphics output: it copies a ROM routine and slightly modifies it (only 4 bytes changed!).

http://www.sinclair.hu/speccyalista/kon ... Manual.pdf

I don't know whether the other printers could work in that way, was it ever tried ?

I think having to wait 10 minutes before it prints anything is a bit of a downer, it would be quicker to draw the graphics with a pencil.

hmm, yes I should have figured it out!
but was it working on different zx printers too?