Xenon
Bally, 1980Looking for a speech prom for a xenon speech board i have which is missing the u9 prom. The part number is E-720-44. The chip itself appears to be a 74188.
If anyone has any info on how to program these, or where to get the file, or has a spare then i'd really like to hear from you 
Apparently the early Flash Gordons had a Vocalizer board too and lists the same PROM part. Unfortunately its PROM dump doesn't look like it's in the wild either.
It would be nice if someone with a game using the Vocalizer board could dump theirs...
There are other PROMs that are equivalent to the 74188, such as the more common 82S23.
Do you have a programmer that supports PROMs? Programmers like the Labtool-48, BeeProgs seem to support them. N.O.S. PROMs can be bought on ebay.
Looking at the schematics and the PinMAME source, it looks like its used as a straight forward address decoder and the data maps out to something like this:
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FE FE FD FD FB FB F7 F7 EF EF DF DF BF BF 7F 7F
PROM address 0 starts at top left, last address is bottom right.
Quoted from Quench:Apparently the early Flash Gordons had a Vocalizer board too and lists the same PROM part. Unfortunately its PROM dump doesn't look like it's in the wild either.
It would be nice if someone with a game using the Vocalizer board could dump theirs...
There are other PROMs that are equivalent to the 74188, such as the more common 82S23.
Do you have a programmer that supports PROMs? Programmers like the Labtool-48, BeeProgs seem to support them. N.O.S. PROMs can be bought on ebay.
Looking at the schematics and the PinMAME source, it looks like its used as a straight forward address decoder and the data maps out to something like this:
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FE FE FD FD FB FB F7 F7 EF EF DF DF BF BF 7F 7F
PROM address 0 starts at top left, last address is bottom right.
Many many thanks for your post. I hadn't looked a pinmame yet, the source there is such a great resource in itself!
I was wondering if it was just an address decoder, but because it was a custom programmed chip i was thinking they must have it doing more than just that. Lesson learned. I'm guessing they needed to do this to allow use of the 8 rom positions and 74 logic was more expensive??
I will check my programmer's device list. I can make the file available for others once i get it sorted no problem
Extrapolating the info from PinMAME, the address map looks like this:
(SoundsPlus board)
0000-007F RAM
0080-00FF PIA
F000-FFFF ROM U4 "811-35_4.532"
Looking at the schematics, the PIA is mirrored all over the place and should be 0x80-0xFF
(Vocalizer board)
8000-8FFF ROM U1 "811-22_1.532"
9000-9FFF ROM U2 "811-23_2.532"
A000-AFFF ROM U3 "811-24_3.532"
B000-BFFF ROM U4 "811-25_4.532"
C000-CFFF ROM U5 "811-26_5.532"
D000-DFFF ROM U6 "811-27_6.532"
E000-EFFF ROM U7 "811-28_7.532"
F000-FFFF ROM U8 N/A
Note: address space for ROM U8 on the Vocalizer board is the same as the code ROM U4 on the Sounds Plus board.
And so the 74188 PROM output pin 7 is wired and enables both U8 on the Vocalizer board and U4 on the Sounds Plus board.
You should be able to replace the 74188 PROM with a 4 to 16 decoder, something like a 74159. It has Open collector outputs, just like the 74188.
Having said that looking at the schematic there's only one device connected to each of the PROMs outputs so you should be able to use a 3 to 8 decoder like a 74138 (cheaper, smaller and easier to get).
Just wire address A15 to pin 6 on the 74138. A12, A13, A14 to the A, B, C inputs of the 74138 respectively. A11 doesn't need to be connected because you don't need the granularity to address 2716 EPROMs.
The rest is straight forward.
Wanna join the discussion? Please sign in to reply to this topic.
Great to see you're enjoying Pinside! Did you know Pinside is able to run without any 3rd-party banners or ads, thanks to the support from our visitors? Please consider a donation to Pinside and get anext to your username to show for it! Or better yet, subscribe to Pinside+!
This page was printed from https://pinside.com/pinball/forum/topic/wtb-or-find-xenon-u9-speech-prom-e-720-44 and we tried optimising it for printing. Some page elements may have been deliberately hidden.
Scan the QR code on the left to jump to the URL this document was printed from.
Leeds
Ocala, FL