GPIB to Serial or parallel printer adapter with the PET

[Eudimorphodon]

The COM2017 UART in the 1450 looks *very* similar to the TR1602B I mentioned earlier. No “intelligence“ there, just a very, very BASIC dumb UART. Looking at the rest of the chips on the board these may very well be almost identical, the one just has the serial converter tacked on.

 

[Hugo Holden]

At this point we know of three PET specific printer adapters, the ADA1200, the ADA1450 and the ADA1800.

The first two perform the same function, in that they are both for a serial printer. But, the ADA1450 is much more elaborate than the ADA1200, which makes me think there was something the ADA1200 couldn't do.

The ADA1200 is currently easy to get, in the UK at least, but I cannot find any 1450's or 1800's for sale anywhere.

When my ADA1200 arrives, I will be able to document it accurately, it also comes with software and a moderate amount of paperwork.

Maybe the ADA1200 was dependent more on software than hardware, but the 1450 and the 1800 did most of the work in the hardware, explaining the extra complexity and many extra IC's.

It would be good to have all these adapters fully documented and understood.

(So far we also know that the 1200 & 1450 units have a Baud rate generator based on a 555, a 10 Turn pot and a Polystyrene timing capacitor).

 

[Hugo Holden]

The COM2017 UART in the 1450 looks *very* similar to the TR1602B I mentioned earlier. No “intelligence“ there, just a very, very BASIC dumb UART. Looking at the rest of the chips on the board these may very well be almost identical, the one just has the serial converter tacked on.

Probably similar by the look of the 74 TTL's but the ADA1450 appears to contain a MC1458 OP amp too.

 

[Hugo Holden]

dbone and MikeS :

If I could have a square on photo of the top and bottom side of the ADA1450 and ADA1800 pcb's (respectively), I could check all the track connections and likely reverse engineer both pcb's.

 

[Eudimorphodon]

Probably similar by the look of the 74 TTL's but the ADA1450 appears to contain a MC1458 OP amp too.

I would bet that is there to help drive the serial lines.

 

[Hugo Holden]

Interesting the info on the ADA1450 instruction sheets mentions Diablo (printers). I had never heard of these, looking on Ebay there is some advertising paraphernalia about these. They look pretty good.

( Imagine that, I'm getting interested in vintage printers now, who would have thought ?)

ITHistory AD (1984) DIABLO PRINTERS "TWENTY SIX REASONS YOU SHOULD BUY (FORTUNE | eBay

(From: FORTUNE 500 June 11, 1984).

www.ebay.com

 

[Hugo Holden]

The COM2017 UART in the 1450 looks *very* similar to the TR1602B I mentioned earlier. No “intelligence“ there, just a very, very BASIC dumb UART. Looking at the rest of the chips on the board these may very well be almost identical, the one just has the serial converter tacked on.

Here is the partial data sheet for the COM17 UART

 

[Ruud]

Do you have more details on it and the schematic ?

My first reaction was: "Nope". But then I remembered that I contacted Black Box 16 years ago (according the time stamp of the PDF) because of this box and a kind person sent me the manual. I just uploaded it: BlackBox_RS232-IEEE.pdf .

FYI: AFAIR I wasn't given any restriction to share it with other people so feel free to copy it and save it on other places on internet as well.

I had a quick look at it: the part list mentions a Motorola 6809 CPU, interesting. Tempted to re-engineer it but I'm busy renovating several rooms so.......

 

[Hugo Holden]

My first reaction was: "Nope". But then I remembered that I contacted Black Box 16 years ago (according the time stamp of the PDF) because of this box and a kind person sent me the manual. I just uploaded it: BlackBox_RS232-IEEE.pdf .

FYI: AFAIR I wasn't given any restriction to share it with other people so feel free to copy it and save it on other places on internet as well.

I had a quick look at it: the part list mentions a Motorola 6809 CPU, interesting. Tempted to re-engineer it but I'm busy renovating several rooms so.......

That looks like a fairly elaborate unit.

 

[dave_m]

That looks like a fairly elaborate unit.

Hugo, agree, it looks like a very nice complete design.

 

[MikeS]

dbone and MikeS :

If I could have a square on photo of the top and bottom side of the ADA1450 and ADA1800 pcb's (respectively), I could check all the track connections and likely reverse engineer both pcb's.

 

[MikeS]

The missing connections:
U12-3: J2-4
U12-4: J2-5
U12-5: J2-6
The other connections to U12-3 to 5 correspond to the schematic as far as I can tell.

 

[MikeS]

Here's all I got today with a ADA 1450 an IEEE to serial printer adapter for the pet.

Photos of the Case, PCB and Manual are located here. (Click the word here.)

Adjusting the baud rate with a trimmer, wild.....

Thanks for that! I've also got an ADA1450 and it's nice to have the instruction sheet.

m

 

[Hugo Holden]

The missing connections:
U12-3: J2-4
U12-4: J2-5
U12-5: J2-6
The other connections to U12-3 to 5 correspond to the schematic as far as I can tell.

View attachment 1243836View attachment 1243837View attachment 1243838

Mike, Thanks. That is just about enough for me to generate a perfect replica board. Could you take just one more photo of the top with the 0.1uF capacitors are bent up straight, so I don't mess up any of the tracks concealed by those ?

(It also looks like they were using a similar pcb for both the 1450 and 1800, just in one case with the UART & OP amp and some extra parts, so it could be possible to build a hybrid universal unit which can do both serial and parallel printer functions, that would be a great PET accessory)

 

[dabone]

I'll try to remember to take more pics tomorrow.

 

[Hugo Holden]

I also decided to buy this vintage unit, there is no manual, but I will subject it to a full examination:

CBM PET Universal Printer Interface | eBay

A rare CBM PET Universal Printer Interface by Taylor Wilson Systems. Clean inside and out, yet with external marks from use and age. It takes the IEEE output from the computer system and converts it to serial RS232 and Centronics parallel ports.

www.ebay.com

 

[Ruud]

Maybe not exactly what you are looking for but what about the Interpod ? OK, it was meant for translating IEC to IEEE plus RS232. What caught my interest in those days was that it was an intelligent device as well: it had a 6502 on board. And therefore I didn't see any reason why somebody couldn't hack the thing to have it bi-directional between all connectors. I started to disassemble it but that it took more effort than I could afford so I stopped with it. I have two versions of it.

 

[MikeS]

Mike, Thanks. That is just about enough for me to generate a perfect replica board. Could you take just one more photo of the top with the 0.1uF capacitors are bent up straight, so I don't mess up any of the tracks concealed by those ?

(It also looks like they were using a similar pcb for both the 1450 and 1800, just in one case with the UART & OP amp and some extra parts, so it could be possible to build a hybrid universal unit which can do both serial and parallel printer functions, that would be a great PET accessory)

Your wish is my command. Hope they're good enough; hard to light properly without reflections.

BTW, do you have the Centronics interface on your version of the AIM65 AH5050 interface? Ever print from your AIM?

 

[Hugo Holden]

Your wish is my command. Hope they're good enough; hard to light properly without reflections.

BTW, do you have the Centronics interface on your version of the AIM65 AH5050 interface? Ever print from your AIM?

Thanks, great photos.

I have never tried to connect the AIM-65 to an external printer, probably because of its internal printer which I used all the time . The AIM-65 printers are quite the masterpiece. When I tracked down spares I found that these little thermal printer heads, were made by Shimadzu in Kyoto Japan, who have a very long history of making high quality precision products dating to 1875 ! They make a lot of medical equipment.

Here is a link to part of their history, great looking headquarter they had in the 1980's era.

History | Visionary | Shimadzu Corporation

www.shimadzu.com

Shimadzu had an office in New York as early as 1963:

【1962 to 1980】Developing and Expanding Markets Throughout the World | Visionary | Shimadzu Corporation

www.shimadzu.com

 

[Hugo Holden]

The large IC in the ADA1200 is an MM5303 UART.

They also have pulled off the interface with just three logic IC's, the '04, an '00 and an open collector NAND the '03. There is a MC1458 OP amp for the serial data to the printer. And one 555 for the Baud rate generator. The unit I have received was made and tested in 1979.

I have not tried it yet, still waiting on the serial printer.