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Olivetti M20 Character Generator ROM

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RetroNora

Member
Joined
Nov 2, 2022
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35
Location
Poland, Europe
Hello,
I've found an Olivetti M20 on a flea market. I'm ashamed to say that, but by a mistake I insterted character generator ROM backwards and fried it.. I have been trying to found its dump online but with no success..
I'm not sure what type of eeprom it is, but there is '6381' typed on it and a badge with PA63, but I guess it's version.
Maybe anyone here have an Olivetti M20 and can somehow make a dump of it?
 

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The table shows it as a 1Kx8. If you have a setup to program fused ROMs you can directly replace it.
If not, you'll have to use an EPROM. If so, you'll need to make an adapter to handle the extra select lines.
Also, you need a fast EPROM if it requires the 55 ns. The old small EPROMs don't come in such faster sizes.
Check the other recent post for M20's. One of those may be able to dump their ROM for you. My stuff
is in storage and I'd need to dig it out.
Dwight
 
I've found the bin file for the CharGen ROM, but since I do not have a setup to program fused ROMs I need to find a way to replace it with EEPROM.
 
RetroNora said:
I've found the bin file for the CharGen ROM, but since I do not have a setup to program fused ROMs I need to find a way to replace it with EEPROM.
Click to expand...
The characters are held in RAM - isn't this the Mapping PROM?
Regards, Graham
 
RetroNora said:
I've found the bin file for the CharGen ROM, but since I do not have a setup to program fused ROMs I need to find a way to replace it with EEPROM.
Click to expand...
Not necessarily. Some companies may be able to supply and program a replacement PROM (6381 or equivalent) for you.
Maybe try contacting:

HobbyRoms - Eprom Programming Services for the hobbyist

Eprom PROM ROM Programming
www.hobbyroms.com

ArcadeComponents.com - Parts and components for vintage arcade games, computers, and game consoles!

ArcadeComponents.com - Providing parts and components for vintage arcade games, computers, and game consoles such as Atari, Commodore 64, VIC-20, TRS-80, Apple,II, Timex, Sinclair, ZX80, ZX81, TI-99/4A, and Colecovision
www.arcadecomponents.com

But per post #3, the other route is an adapter for the (fast enough) replacement EPROM. According to the link in post #2, the 82S181A is an equivalent PROM. The thread at [here] is an example about someone making up an adapter for the chosen replacement .
 
The PA63 is not the character generator (the character set is in the regular bios) but a memory mapping bipolar prom.

I have a labtool 48xp and can program some equivalents (for example the 27s181, which you can easily find). Where are you located?
 
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