scitari

There is a nice 820 for sale on eBay right now. A bit pricey ($225 BIN) but it looks to be in really good condition. Very happy with the one I got last month.

I would focus on the ANTIC chip that was revolutionary at the time. The ability to mix graphics modes on a the screen with display lists was unique at the time as were display list interrupts that Atari engineers wisely built in to allow line by line control of the graphics making it possible to put 256 colors on the screen at the same time. You could then end with a discussion of player-missile graphics. The ability to have players and missiles sent to the TV as an independent signal from the playfield graphics is amazing and blew the competition out of the water. Apple, Commodore, and Radio Shack had nothing like this when the Atari 400 and 800 were released in 1979. Wow! A point in tech history that college students studying computer engineering, graphics, or game design must know about. Their education will not be complete without this essential background. Gives me the chills just writing about this. Pure awesomeness.

I love my 820 and feel really lucky have it. I think my 1020 plotter is pretty cool too but there is something so satisfying about watching this little dot matrix print and then ripping off the receipt-sized printout. I also really love the aesthetics and how it sits perfectly on top of the 810. The only thing better is to have an 815 to go under the 820. Here is my setup. I posted this on the 8-bit FB page as well.

Those of you new to Atari 8-bit computers might find my Atari Projects web page useful. I have posted a number of projects with instructions that can be completed in a few minutes to a few hours. These cover hardware, software, programming, and media. Enjoy!

Here is my blog post about this.

I am pleased to report that the Atari 820 ribbons from Ribbons Unlimited worked beautifully and you can order as many as you want! They are a family business and a real pleasure to work with. Here are some photos of the ribbon in my 820, a test print, and the box the ribbon came in with the part number listed.

My ribbons from Ribbons Unlimited arrived. I will try them out this weekend and report back. I have to say I was very impressed with their service. A please to work with.

Right?!?

The 40th birthday of Atari 8-bit computers is coming up soon next year in 2019. What do folks think about the milestone? Something to celebrate? Just wait until the big 50 comes along in ten years? How should we celebrate? The 40th sure makes me feel old!

Awesome! There are now three sources of ribbons. 1) Best Electronics 2) Ribbons Unlimited 3) Paper Systems Incorporated Now to nail down additional paper sources.

Maybe annotate the final list with the media they were available on. Only some of these came in cartridge form. Thanks for posting!

Would be great to confirm this. It would be nice to have several sources of ribbons for the community.

Someone needs to do this. What a brilliant idea. AtariMUD. AtariMUSH. Love it. I was a regular on ApexMUSH back in the early 1990s. I spent a bit of time on BioMOO as well.

I worked with a company called Ribbons Unlimited. They were able track down compatible ribbons and added them to their website under Atari 820. They might have made them. Not sure. I ordered three and will let you know if they work. They sell them for $8.95 each.

I may have found a source of ribbons. In the middle of an email exchange now. Will update when I have confirmation of the price.

Was able to find Atari 1025 compatible ribbons online for $8.95 each. They sell ribbons for a bunch of old DM printers. The 820 is not mentioned. Maybe one of the ribbons they sell for other printers will work with the 820???

Here are the tech specs for the Atari 820 printer from the original manual.

How about this for paper? Hard to find 4 inches - 100mm. Much of what I see that is about this size is thermal.

Got a link to what you bought? Thanks!

Here is the cleaned up and working code. Here is a version with comments added. Thank everyone for your help! Very much appreciated. Learning this for the first time. I also did a post about this on Atari Projects. Comments welcome. 10 GRAPHICS 0:POKE 752,1:PRINT " " 20 DL=PEEK(560)+PEEK(561)*256 30 REM read in assembly code to modify graphics 40 FOR I=0 TO 49:READ B:POKE 1536+I,B:NEXT I 50 DATA 72,152,72,172,0,4,185,2,4,141,10,212 60 DATA 141,24,208,238,0,4,173,0,4,205,1,4 70 DATA 144,5,169,0,141,0,4,104,168,104,64 80 DATA 165,20,197,20,240,252,169,192,141 90 DATA 14,212,104,104,104,96 100 REM modify display list for interrupt 110 FOR I=6 TO 27:POKE DL+I,PEEK(DL+I)+128:NEXT I 120 FOR I=2 TO 3:POKE DL+I,PEEK(DL+I)+128:NEXT I 200 REM read in background color data 210 POKE 1024,0:POKE 1025,24 220 FOR I=0 TO 23:READ B:POKE 1026+I,B:NEXT I 230 DATA 25,20,25,20,25,20,25,20,25,20,25,20 240 DATA 25,20,25,20,25,20,25,20,25,20,25,20 300 REM point to DLI on page 6 and enable interrupt 310 POKE 512,0:POKE 513,6 320 X=USR(1571) 1000 GOTO 1000

Thanks! Very helpful. It is amazing how little detail there is in the programming books from back in the day. I am guessing many authors were rehashing what was in De Re Atari which was also a bit light on details. One last question. Why is the cursor still on after POKE 752,1?

Yeah, saw that but a Google search on that string was not helpful. Thanks!

I have been working with some DLI code and can't figure out why the first two lines of Graphics 0 don't draw correctly. What am I doing wrong? I have tried a number of different variations. Here is the text file. The code and a screenshot from Altirra is below. Many thanks!!! 10 REM assembly code from https://www.atariarchives.org/alp/chapter_8.php 15 REM see listing 8.2 20 GRAPHICS 0:POKE 752,1 30 SETCOLOR 1,0,0 40 DL=PEEK(560)+PEEK(561)*256 45 REM read in assembly code 50 FOR I=0 TO 34:READ B:POKE 1536+I,B:NEXT I 60 DATA 72,152,72,172,0,4,185,2,4,141 70 DATA 10,212,141,24,208,238,0,4,173,0 80 DATA 4,205,1,4,144,5,169,0,141,0 90 DATA 4,104,168,104,64 95 REM modify diplay list for interrupt 100 FOR I=6 TO 29:POKE DL+I,PEEK(DL+I)+128:NEXT I 195 REM read in background color data 200 POKE 1024,0:POKE 1025,24 210 FOR I=0 TO 23:READ B:POKE 1026+I,B:NEXT I 220 DATA 25,20,25,20,25,20,25,20,25,20,25,20 230 DATA 25,20,25,20,25,20,25,20,25,20,25,20 235 REM point to DLI on page 6 and enable interrupt 240 POKE 512,0:POKE 513,6:POKE 54286,192 250 GOTO 250

Has anyone identified a commercial ribbon that can be used in the 820? Part number? I see Best sells them (limit 1) but I assume this is NOS. Thanks!

The rise and fall of Atari is bot amazing and sad. A great story!