Sinclair ZX80 / ZX81 / Z88 Forums

Based on JSSpeccy, with so far only FAST mode:

http://rullf2.xs4all.nl/jszeddy/jszeddy.html

[Using a <canvas> and tested using a recent Firefox under Linux.]

Would it be possible to use the tv modulator - via a resistor - as a logic probe? If everything is well, all signals are in sync with the image, but perhaps even when the computer does not boot, some signals may be visible?

Perhaps using system variable FRAMES directly?

That would take just a few extra bytes!

Would you consider returning from the machine code to just do the INPUT in BASIC? This will be the easiest and probably the smallest. 100 print usr 16514 110 input a$ 120 print a$ 130 goto 100 The following code gets the A$ at line 110 from NXTLIN and some increments and stores this at CH-ADD. It th...

Returning from input at 0x0ee9 seems to be tricky indeed, unfortunately

You're right! And this seems to work too and is two bytes shorter. It just interprets "INPUT A$".

In the code in the attachment system variable "ch-add" is set to point to the text "A$" at the end of the line, and then "look-vars" and "input" are called.

Very interesting - thanks!

May be we can compare intermediate results: for num=12345, intnum=3236167680, tmpint1=0 and tmpint2=49380 or 0xc0e4 but it should be 0x40e4?