Supra MPP 1100 printer connection

[sup8pdct]

Found this interesting page.

 

http://ftp.isu.edu.tw/pub/Hardware/modem/Diamond/supra/supra/deadprod.txt

 

A line says this

C64             Big Blue - printer interface (OEMed to CardCo) -NSR since '92

Maybe 1st half is c64 stuff.

 

James

[1050]

Another line goes

 

CardCo AT - CardCo OEMed our printer interface -NSR

 

This rom had AT on the sticker, didn't know if that was the PC or not.

 

But it says MicroPrint on the label and we have

 

MicroPrint - printer interface. -DSR '94

 

So if this were 1994 I could get it serviced !!

 

 

We never supplied

them the interface, only the C64/Atari 8 bit

interface, but Protecto keeps refering people to us

 

Sounds like your hunch is right on the money by that one, they speak of it as one interface.

 

Hard to swallow the business about the 374 and shared lower 8 address lines with data lines. WOW, this is going to take a few days to grow into that concept. Thanks, most interesting.

[sup8pdct]

Check out schematic of XF551. It uses a 8050 or 8040. same as 8049 except for amount of ram. it has a similar latch with external rom.

It would appear that all code required is below $200. Cannot find any calls or jumps in 1st $200 to reference anything from $200 on. So all the rest is for ??

 

James

[1050]

Yeah, I'll have to do extensive checking on all these again. The latch is working very good I must say, but still a big concept to lump over for me. And after that no surprise at all to learn the 8040/50 is doing the same darn thing all along.

 

I've always had a problem trying to understand that sel mb1 business if I even remember it right in this sentence, but I've always assumed somehow they use that to hop around in the code with. Your guess is better than mine and I'm pretty confident in saying that. Short look around confirms this issue and I see that it's able to be programmed and the internal program read but no real instructions on how to access that code. ALE (pin 11) seems to loop back around to pin 24 (P2 bit 3) but I can't confirm a thing because I just happen to NOT have any analog meters inside the house tonight. I'll round some up and keep them where I need them. I strongly suspect they programmed the internal 2K rom and we have no idea what's on it at all as of yet. Need more time for pin probing and datasheet reading to uncover this one I'm afraid. I thought that reset vector area of zero address area was a tad sparse with one jump. XF551 code seems well populated in that same place in comparison. For one datasheet I've got something called Grokking the MCS-48 System which is several related datasheets in one package, I'm thinking I need more too. Some kind of development board that was made to extract and program this information would be handy right about now.

 

I did spot big blue interface entry in both C64 and Atari 8 bit line after posting above so that must be the in house name for the dual interface. Still wonder about the AT on the label and just what OEMed in past tense means exactly when used from/at/to another company like that. Whom did what to whom first, second and last in other words.

[sup8pdct]

Looking through the code, this device responds to both P1: and P2: just like the 850 interface.

 

James

[sup8pdct]

to add CR and LF, do the following.

xrl a,#9bh ; 00e4 - d3 9b S. = 9B EOL?
jnz X00ec ; 00e6 - 96 ec .l jump if not
mov r1,#0ah ; 00e8 - b9 0a 9. change to CR
;
; for cr-lf, change following to- jmp x01c0 ; 00ea - 24 c0
mov r3,#0 ; 00ea - bb 00 ;. set eol flag
;
;---------------------------------------------------------------
X00ec: nop ; 00ec - 00 .
nop ; 00ed - 00 .

-------------- snip --------------------------------------------

X01bd: nop ; 01bd - 00 .
;
;add following here for CR- lf -----------------------------------------------
;
org 1c0h
x01c0 mov r3,#0 ; 01c0 - bb 00
nop ; 01c2 - 00 .
nop ; 01c3 - 00 .
nop ; 01c4 - 00 .
nop ; 01c5 - 00 .
mov a,r1 ; 01c6 - f9 y
outl p1,a ; 01c7 - 39 9 out to printer
anl p2,#0efh ; 01c8 - 9a ef .o assert strobe
orl p2,#10h ; 01ca - 8a 10 .. release strobe
mov r1,#0dh ; 01cc - b9 0d 9.
jmp x00ec ; 01ce - 04 ec
; end add following---------------------------------------------------------------


;----------------------------------------------- same as 1st half of rom
org 200h

That should work. totally untested.

James

[1050]

Thanks, I'll save this in my MPP folder and give it a try. Can't even say when at this point, sure would be nice if the 4 meg ram project could help me get my 800XL back together soon cause that's when it would happen. OP must have not won the auction or is busy elsewhere at the moment. Understood about untested rating, I'm learning here just reading your comments, and very much to learn about this micro, thanks again.