uPD7220

Andrew this web site is great for any chip data sheet (.pdf's)

WoW ! I designed an S-100 board for this chip almost (not quite)

I rememnber having a spiral bound programming book for this but don't know if I still have it or not... Will take a look but not promising anything.

All data sheets had a 2 page data sheet and pinout for it but that's all I could see in the 1 minute I checked.

This was a very cool chip at the time. Drawing lines and circles and stuff. I always use my hand wired board for proto examples for young whipper-snapper engineering types.

There was a small home computer that used this chip as well but can't remember who's it was now. Heathkit ? Rat Shack ? Apple ?

boB

Hi Bob! Thanks! There are a few early microcomputers that used this chip. The Epson QX-10 and NEC APC are a couple examples. There are more.

If you have any design information on the uPD7220 especially an S-100 board design please scan them in and post. There is very little information available for the uPD7220 and I fear it is in danger of being lost to the mists of history. I am collecting the data for a possible future project.

Thanks and have a nice day!

Andrew Lynch

The NCR DMV used this chip for its graphics operation. I have scans from the system technical manual (check your email ;-) )

Regards, Robert

Most of the small home computers tended to use 6845, 6847 or some custom made clone of that basic functionality. TI had their own brand 99x8 GDCs with sprites and other goodies.

It was a beautiful little chip way ahead of its time with upto 1024x1024 by 256 colour graphics and hardware accelerated line, arc and fill. It was what the PC graphics standard should have been but instead we were stiffed with IBMs poxy VGA. In Japan the 7220 was the mainstream GDC on all NECs 9801 series computers capable of full Kanji character display.

I might still have an English applications datasheet in a trunk in the attic somewhere - a quick look didn't find it. I once wrote an Intel driver for it a long time ago. I recall it had some handshaking issues on PCs with the result of TEST AX,imm instruction failing intermittently on 286 CPUs (AND AX, imm was OK). Apart from that it was nice to use and for the time exceedingly fast excellent for engineering and science applications. I have some Japanese language data on the 9801 but that probably isn't much use to you.

A Californian company produced a nice but expensive 7220 based ISA board for the PC called Sigma Dazzler in the early 80's and with a sufficiently expensive colour monitor it was magic to use. Few customers could afford the daughter board to do 256 colours, most settled for 16.

Regards, Martin Brown

Hello, Martin!

Finally, someone else than me who had experience with it! Too bad you did not respond when I mentioned it, several years ago.

We had a Japanese, but he has disappeared, unfortunately. (I have a rarity in Japanese that I would like to be checked by a Japanese.)

Personally, since nobody has managed, so far, to write a VGA screen driver for CP/M-86, my conclusion is obvious: drop the wretched MC6845 and use Good Old 7220. The problem is finding such a rarity for the IBM Clown. So, many thanks for mentioning this one.

Question: I found only one reference on the Internet about the "Sigma Dazzler 1", but many about the "Sigma Color 400". What was it?

Yours Sincerely, Mr. Emmanuel Roche, France

Look for a product called metawindows (portable VGA driver with higher level interface and ISTR about a 100k footprint). Simtel archives might have it if you are lucky. There is probably a Turbo/Objective Pascal or M2 portable VGA driver that could be put onto CP/M-86 with only modest effort.

Definitely the Dazzler 1. I don't recall any higher numbered Dazzlers. There was at least one other (even more expensive competitor). Their Color 400 I think was some colour Hercules abomination with VGA clone tendencies - early graphics cards post VGA were a real mess.

Windows took off by abstracting them and removing some of the pain!

Regards, Martin Brown

Hello, Martin!

Found it! Seems the company is still alive but seems, obviously, to make other things:

- The last "Newsletter" is dated 2001...

- The only articles mentioned are dated 1993 and 1994...

But I downloaded MWDEMO, and it runs.

Now, all I have to do is understand how its driver is working.

So, thank you very much for giving me yet another thing to do!

In exchange, if you are still interested in the NEC uPD7220 GDC, the source code of one B&W driver is available at:

Go down to NCRGRAPH.ASM then enjoy!

Yours Sincerely, Mr. Emmanuel Roche, France

Hi Bob! Did you ever locate your design information of your S-100 uPD7220 graphics board? If so, would you please contact me by email.

Making a uPD7220 would be a perfect application of the N8VEM S-100 prototyping board. If you find your information this would be a neat project.

Speaking of the N8VEM S-100 prototyping board and S-100 backplane, I am trying to put together a group purchase of PCBs. If I can get enough committed buyers (20 S-100 prototyping boards and/or 10 S-100 backplanes) I think I can arrange a new manufacturing order. I am guessing but I expect the final cost to be about $20 each or less plus shipping. I have 8 S-100 prototyping boards and 4 S-100 backplanes reserved already so we are a good portion of the way there.

Please keep looking for your S-100 uPD7220 design information. That would be an invaluable find of historical information and certainly worthy of preservation. There is precious little information available on the uPD7220 and legacy designs.

Thanks and have a nice day!

Andrew Lynch

Hi,

If anyone is still looking for a NECuPD7220 (40-pin ceramic DIP), I have an unused one in my odd-IC collection which I'll never use. Sorry, but I don't have any data sheet for it.

E-mail me if interested - I'm in London, England.

- Dave

David C.Chapman - Chartered Engineer. FIET. ( snipped-for-privacy@minda.co.uk)

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