ZX Spectrum +3 problems

[AmstradCPCcool]

Hi there,

I'm having problems with the Retroprinter on my ZX Spectrum +3. It works brilliantly with my Amstrad CPC6128 but every time I use the Lprint command in both +3 Basic and 48k Basic, nothing seems to be outputted to my Retroprinter device. I have posted previously on here and my Amstrad CPC issues were solved.

Is there anything I need to do additionally with my ZX Spectrum +3?

[RWAP]

So far as I know, the Spectrum +3 and the Amstrad CPC6128 use the same printer edge connector (although I am not sure).

I had to have a quick look at the Spectrum+3 manual - https://worldofspectrum.org/ZXSpectrum1 ... 8pt21.html

LPRINT and LLIST are redirected to the printer port (at least in 128K BASIC - in 48K, I believe they still go to the expansion connector for the ZX Printer). However, you need to set the /root/config/auto_linefeed to Yes

Check if it is capturing anything in /home/pi/data/raw - it will not generate any output until there is a full page of A4

[AmstradCPCcool]

Hi,

I've changed the autofeed setting and I now get pdf files but I get googledegook instead of what I had initially written in +3 basic. I get the raw files. The data input light does not seem to light up like the Amstrad CPC did.

What next ?

[RWAP]

Post examples of the output and what you are trying to print from BASIC - I am flying blind as I don't own a +3 Spectrum and not many people have a +3, and the AMSOFT PL-1 Adaptor

You may need to change the /root/config/bit_depth to 7

[AmstradCPCcool]

Hi.

Here is the first example attached. Before changing to 8.

It was supposed to say 'Hello spectrum 128'

I have changed it to 8. The RAW file and EPS files are being produced but not the PDF.

Can this be remedied?

[RWAP]

OK so that looks not to be related to the 7 bits / 8 bits; so I am at a complete loss and you are basically asking me to figure out the issue completely blind

It looks as though it might be something peculiar about the Spectrum hardware - it could even be that the printer edge connector on the Spectrum+3 is worn or filfthy and needs cleaning. There is little information about the two printer edge connectors on the Spectrum and the Amstrad CPC, and after all, the Retro-Printer works with the Amstrad....

If the PDF is no longer being generated - how did you alter the /root/config/bit_depth file?

If you edit it in Windows - you have to be careful that you do not change the line endings from Unix !

Try :
cd /root/config
dos2unix *

Can you send the raw files and retrporinter.log file?

[flatduckrecords]

Hi there,

I'm having problems with the Retroprinter on my ZX Spectrum +3. It works brilliantly with my Amstrad CPC6128 but every time I use the Lprint command in both +3 Basic and 48k Basic, nothing seems to be outputted to my Retroprinter device. I have posted previously on here and my Amstrad CPC issues were solved.

Is there anything I need to do additionally with my ZX Spectrum +3?

Hi AmstradCPCcool,

I realise I'm replying to an old post, but I had the same issue so I wanted to add some more information!

The problem is due to a bug in the Spectrum +3 ROM. The system variable BANK678 is not initialised correctly - so the strobe signal (on pin #1 of the printer connector) is not set properly. This was corrected by Amstrad in the +2A (which came out after the +3) so most printers, including the Retro-Printer work with it as expected. If you are comfortable changing the ROM ICs in your +3 (and have access to an EPROM programmer etc.) then that would certainly fix the problem - that's what I did and now my +3 is printing quite happily!

The parallel printer port can't be used from 48K BASIC at all - that will only work with the expansion port-printers like the ZX Printer or Alphacom 32.

[flatduckrecords]

For a temporary fix, it's possible to enable printing in the v4.0 ROM with a couple of POKEs. Be sure to enter it on one line like so, otherwise the Spectrum will crash if you enter the POKEs separately. (Or it can be done within a BASIC program).

Code: Select all

POKE 23354,62:POKE 23355,16

[source: https://worldofspectrum.org/forums/disc ... ent_199071]

For a slightly more robust fix, POKE the following 11 bytes, starting from 23355:

Code: Select all

  10 FOR i=23355 TO 23365
  30 READ n: POKE i,n: NEXT i
  50 DATA 62,16,1,253,31,237
  60 DATA 121,50,103,91,0

This does the same thing, but preserves the "disable interrupt" instruction during ROM paging.

[RWAP]

I also had a look at how we handle the STROBE signal on the Retro-Printer. Unfortunately, this would involve a hardware change to support what is, after all, a bug in the ZX Spectrum +3 ROM.