Trying to get HP Laserjet 4P to work with my Atari 8-bits.

[+Allan]

I'm trying to get my HP Laserjet 4P working with my 130XE. I got it to print 'Hello' but it doesn't want to do a carriage return. It prints all the lines on one line. Does anybody know what I need to do to get it to print correctly? Some option on the printer maybe? I'm using a Supra Corp. MPP-1150 Parallel Printer interface.

 

Allan

[JayoK]

Just a guess... but doesn't the atari us a different character for carriage return than HPs. The reason I know this? I had to do something similar and I needed to write a P: driver that simply swapped the ASCII code 13 (for CR) and the ATASCII code (155 or $9B).

 

You can get the full code set from here

 

http://www.faqs.org/faqs/atari-8-bit/faq/s...section-48.html

 

Oh the flashback of 8-bit coding! PCs are overrated!

 

Jason.

[JayoK]

Actually thinking about this some more.. this code could be very easily written. As a test you could do something like this in BASIC

 

10 OPEN #1,6,0,"D1:PRINTME.TXT"

20 OPEN #2,9,0,"P:"

30 TRAP 80

40 GET #1,A

50 IF A=155 THEN A=13

60 PUT #2,A

70 GOTO 40

80 CLOSE #1: CLOSE #2

 

Ok, so the OPEN syntaxes may not be right but you get the general idea. For the P: driver you need to locate the IOCB table and the corresponding code for putting out a byte to the P: device. I would image that the code somewhere would have LDA BUFFER, STA POKEY_OUTPUT. You could circumvent this with a small patch. Replacing like this

 

** LDA BUFFER ** Removed

JSR MODIFIED

STA POKEY_OUTPUT

 

.ORG $00D4 ;in page zero but could be anywhere

;don't use FP when printing

 

MODIFIED

CMP #155 ; is it Atari EOL?

BNE RETURN ; Nope then just continue

LDA #13 ; It is then replace 155 with 13 (EOL)

RETURN

RTS ; all done, return!

 

 

 

So what have I done here? Got carried away, that's what! The code is not 100% accurate as I don't have any of the coding books with me at the moment but you probably get the general idea.

 

One final option is to reprogram the HP printer character set, now that's a whole mountain of work.

[+Allan]

Thanks JayoK for all that work. I think though that there might be an easier solution. I know some people have mentioned that they have used this printer with great results before. All I did was LPRINT something from BASIC. I will try to hunt down a printer driver for AtariWriter next. I'll try your solution if that fails.

 

Allan