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First character generator chip

falter

falter

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I've been collecting character generators for a while now.. I'm just fascinated with them and all the different character patterns they produce. I scored this 2526 for 1 cent. I may use some in projects, or otherwise just display.

But I'm curious.. ive been trying to figure out, if it's possible, what the first character generator IC was, whose it was etc. Any thoughts? I've been googling but it doesn't seem to be a subject of great interest, and wiki comes up with the TV character generation machines rather than ICs.
 

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The first commercially available mask-programmed MOS ROMs came out in 1965.

1965: Semiconductor Read-Only-Memory arrays | The Storage Engine | Computer History Museum

www.computerhistory.org www.computerhistory.org

I‘m having trouble finding it at the moment but I remember seeing a Fairchild datasheet for a very early bipolar PROM that used “character generator” as its example application; it only had numbers and a few symbols because it was intended for a CRT calculator (companies like Frieden made them) and the tiny amount of storage space available, but it makes me guess that ROMs specialized for the task came along very shortly thereafter.
 
This 1970 TI data book lists the TMS2400JC series, which is a 64x5x7 character generator similar to the Signetics 2513. (Except it has really strange voltage requirements that would make it… difficult, to interface to today.)


The oldest Signetics databook with MOS parts on Bitsavers is from 1971, which lists the 2513, so… theoretically the TI might be a year older? There were some older books that list ROM parts and name character generation near the top of the list of applications (I found that Fairchild example using a 9034 in a 1969 book) but I’m starting to think 1970 was about the year that ROMs got dense enough to pack a full alphanumeric ASCII subset into a single chip. If anyone can find one older than the TMS2400JC, well… I think it’s going to be hard to beat.(*)

(* The 1970 Fairchild catalog has a listing for a numeric-only CRT character generator, but it doesn’t look like they got alphanumeric until the next year. Haven’t run down the other parts listed in that Don Lancaster article. Undoubtedly Steve Wozniak invented one in 1958 while eating his Captain Vita-Man cereal in front of Howdy Doodie, but we’ll need to wait until his next podcast for a part number.)
 
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The MC4039P was termed "character generator" by Motorola. It was a pre-programmed XC170 mask-programmed ROM from about 1968 and was, essentially a binary to 7 segment encoder in 128 bits. here. It's in the big brown 1969 databook, but not the red 1968 one.
 
On a hunch I looked up the service manual for the Datapoint 3300, which was supposedly introduced in 1969, and it says the first few revisions used a TMS4100JC family part. (Also listed in that 1970 data book.) So that pushes full alphanumeric CRT character generators back another year.
 
Well, sure. A character generator ROM is a natural. MOS ROM capacities really jumped from almost 0 in 1967 to kilobits in 1970. Things moved really fast in the late 60s-early 70s.
I submit the block diagram of an early raster-scanned video terminal, ca. 1966-68. Note that line memory was delay line and character generation was diode matrix:Screenshot_2022-10-24_09-31-13.png
 
Cheers.

I will have a more detailed read tomorrow. Just had a quick look new before I call it a night.

Dave
 
Chuck(G) said:
Things moved really fast in the late 60s-early 70s.
Click to expand...

It really is pretty crazy. terminals-wiki.org has a "year of introduction" index, and as late as 1967 the entries are mainly IBM 2260-style machines that relied on a refrigerator-size control box separate from the CRT console and made use of technologies like acoustic delay lines for the character memory. (Scanning the docs @Chuck(G) just posted it looks like that device would also fall into that category.) And then in 1969 you have the Datapoint 3300 with all solid-state memory (an absolute bucket-load of shift registers) and a MOS character generator all in one (very chunky) box. Kind of mind blowing(*).

(* And then within four years of that the parts had gotten cheap enough for Radio-Electronics Magazine DIY articles...)
 
Al Kossow said:
details from all of the little MOS companies in the late 60s is hard to come by.
the earliest I can find 'mos rom' in the scanned magazines I have is 1969
this is the first mention I see of a part designed to be a character generator
http://bitsavers.org/magazines/Computer_Design/196910.pdf pg 47
Click to expand...

That's a neat find. It looks like when they put this together their densest parts were 1024 bit, so what they're advertising is a kit of three pre-programmed ROMs each containing a third of the dots, teamed with a counter that handles patching up the the ROM selection and addresses appropriately for the row you're on.
 
I am enjoying reading about all of this! Really interesting to follow the path backwards and see where it goes.
 
the datapoint 3300 being introduced in jun, 1969 is about the earliest you're going to see with a mos rom and shift register memory.
the state of the art in shift registers ca. mar, 1969 was 512 bits
http://bitsavers.org/magazines/Electronic_Design/Electronic_Design_V17_N05_19690301.pdf pg 64

it uses a TI character generator

though there were some terminals using core memory (Hazeltine 2000, jun 1970?)

the wikipedia article quotes Mike Holley as saying the 3300 was introduced in 1967

Wayback Machine

web.archive.org web.archive.org

but that can't possibly be correct since the announcement in a magazine I've found is two years later, and especially since
the shift register memory technology they used didn't exist until 1969
 
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Yeah, it kind of feels like if we're restricting this race to single chip character generators the TI TMS4100JC series might be the absolute earliest, but the main piece of evidence to support it is the intro date of the 3300 cross-referenced to what its service manual says was in the earliest version. It kind of looks like everybody making MOS ROMs started churning out specialized character generators as soon as their bit density hit critical mass, though, so it wouldn't surprise me to find out Signetics, National, or one of the other companies was sampling their parts at around the same time.
 
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