Sinclair ZX80 / ZX81 / Z88 Forums

But what happens with repeated LPRINT?
Is the second LPRINT again at the first position? I would expect it to fill the printer buffer until it's a full line and then print the line.
Is there an easy way to get the current printer position and is it enough to reset this?

I would make code like this:

PRINT (c$(1)+c$(2)) AND USR n

where at N the data on the calculator stack is fetched and a result with BC =0 would prevent any display.
Used it on the ZX Spectrum many times.

siggi wrote: ↑Tue Mar 21, 2023 9:45 am
using
21 LPRINT C$(1 to 2);
is easier.

Then the machine code can fetch PRINTABLE(!) characters from printer buffer (address 16444....) and the length of the basic code does not need to be calculated to call the machine code (line 20).

A single number X can be passed to m/c using RAND X and fetch the number X from address 16434

I'll have to play around with this idea, it may be possible to pass all parameters if they're less than 256 via LPRINT...

LPRINT C$(1 TO 2)+CHR$ X;

Greg

Paul wrote: ↑Tue Mar 21, 2023 11:50 am But what happens with repeated LPRINT?

If the printer buffer reach 32 characters, it prints the buffer!

10 LPRINT "ZX81";
30 GOTO 10

This example reset the printer buffer:

10 LPRINT "ZX81";
20 POKE 16444,118
30 GOTO 10

In ASM:
LD (IY+60),118

Or Set the PR_CC to 60 ( Offset from IY =PR_BUFF): "20 POKE 16440,60"
LD (IY+56),60

XavSnap wrote: ↑Tue Mar 21, 2023 11:02 pm

Paul wrote: ↑Tue Mar 21, 2023 11:50 am But what happens with repeated LPRINT?

If the printer buffer reach 32 characters, it prints the buffer!

10 LPRINT "ZX81";
30 GOTO 10

This example reset the printer buffer:

10 LPRINT "ZX81";
20 POKE 16444,118
30 GOTO 10

In ASM:
LD (IY+60),118

Or Set the PR_CC to 60 ( Offset from IY =PR_BUFF): "20 POKE 16440,60"
LD (IY+56),60

Thanks Xav, exactly what I was looking for!

GCHarder wrote: ↑Tue Mar 21, 2023 9:47 pm

siggi wrote: ↑Tue Mar 21, 2023 9:45 am
using
21 LPRINT C$(1 to 2);
is easier.

Then the machine code can fetch PRINTABLE(!) characters from printer buffer (address 16444....) and the length of the basic code does not need to be calculated to call the machine code (line 20).

A single number X can be passed to m/c using RAND X and fetch the number X from address 16434

I'll have to play around with this idea, it may be possible to pass all parameters if they're less than 256 via LPRINT...

LPRINT C$(1 TO 2)+CHR$ X;

Greg

Same as for PRINT on screen: non-printable chars are LPRINTed as "?", so 0-63 and 128 to 191 are OK

I'm tending to forgo using LPRINT for parameter passing as it would make the programs incompatible with ZXPand.

Regards;

Greg

I've uploaded a new version of the "Inline" program. I've done away with all the POKEs for parameter passing. Without the POKEs the GOSUBs are no longer needed so things are bit faster as well.

Parameter passing is now in the form...

10 PRINT USR FILL;[Lines],[CODE CHR "X"]

I've added two new routines "Quick Print" and "Spiral Wipe".

See Readme for details;

Enjoy;

Greg

Makes a nifty display.

I'll add this to the main program later on I'm still working on other routines as well.

Enjoy;

Greg

Thanks Greg.