MAMEWorld Forums - News - DU January News Roundup

>>I wonder if the hardware is same operation where the tape is an audio tape and the
>>tape data is converted by a chip to appear to be readable character text on the
>>monitor when a player is playing the game. Ramtek Trivia which was released in 1975
>>does it that way.

>*edit* nevermind that, i misunderstood your description

Heh. It's a bit more involved than what the cab appears to be when first looking at the cab.

The pcb has a 2513N ASCII Character Generator chip and that is used to generate ASCII images from the audio data that is played on the Trivia 8 track data tapes.

There is one known prom chip type 6331 (at location E3 or 3E) on the Trivia pcb. The prom contains text data that is displayed describing the players results: good, bad, terrible etc.

The remaining text and numbers is generated from the tapes or circuit components on the Trivia pcb.

After looking at Quiz Show manual, it appears Quiz Show does not use a 2513N ASCII Character Generator chip. Quiz Show handles displaying the questions data from tape in a different manner compared to Ramtek's Trivia. I forgot that Quiz Show is a dual board hardware game.

Here is an excerpt of a thread from summer 2008 (only italie and mw's posts saved) when there was a thread dealing with Trivia pcb and Trivia tape cartridges. This was about 5 months before Ramtek Trivia logic schematics were found because only had Ramtek Trivia manual which barely helps aside from the wiring diagram.

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Datasheet Gurus....I need any info that you can find on a 2513N Character Generator
08/17/08 03:45 AM

Here is all I know so far, which is a bit less that I need.

2513N
ASCII Character Generator

Specsheet / Datasheet

Display Mode=Row Scan

No. of Char.=64

Bits Per Char.=40

No. of Outputs=5

t(a) Max. (s) Access Time=600n

P(D) Max.(W) Power Dissipation=730m

Nom. Supp (V)=5.0

Status=Discontinued

Package=DIP

Pins=24

Technology=PMOS

Re: Datasheet Gurus....I need any info that you can find on a 2513N Character Generator
08/17/08 05:48 AM

Just one, fed by or feeding two 2101 Rams. There is also an few NE565A PLL ICs, and a few tiny unknown eeproms or PICs, don't want peel the marking tape off just yet.

Other than that, it's pretty run of the mill 74 series ICs, a couple oddballs here and ther like a 7445s

Re: Minor breakthrough
08/19/08 02:05 AM

> That seems like you've cracked it, but the map is a slight off? or just bit errors.
> I'm eager to see what the outcome is. h = ? and p=linefeed?

I haven't got all the answers yet, but here's the pattern I found:

Code:

Each packet: "0" start bit
six data bits, lsb on left
one extra bit - purpose undetermined as of yet.
"1" "set" bit - parity position?
"1" stop bitMapped with char table (from data sheet):
@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_ !"#$%&'()*+,-./0123456789:;<=>?
example:00101000110100000011011000001101101000110000001011011010001100100100110100000011
0101000 1000000 1100000 1101000 0000010 1101000 0100100 1000000
10 1 3 11 32 11 18 1
J A C K (space) K R A

I'll decode the other samples and upload in a few more minutes.

By the way, the latest .wav file you posted is 44 mb, it'll take me a little while to download it. In the meantime, I'll cut a chunk off of it and see how it looks.

Edit:

The other samples show signs of decoding with more sports trivia, but they need to be 10-bit alligned first. That's going to take a little while. Just a heads up. Feel free to decode your own from the previously attached "bins.zip" file. I'm going to investigate the 7th bit and see if it does some kind of formatting first.

Edited by mw (08/19/08 02:18 AM)

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Edited by gregf (01/25/14 10:16 PM)