So, the pinout for the Model 600 opt rom socket is plain 27256, not the funky pinout from 100/102/200.
This means, the most convenient way to make a custom rom, is if you had the original carrier so you could uust slap an ordinary dip28 27C256 in it. No pain in the neck module with a soic soldered in the middle like mombo, rombo, figtronix, etc. And ideally, you don't want to disassemble your Multiplan rom to use that carrier. Well I was just about to slog through the tedious job of drawing up a cad model of the carrier so anyone could get a new carrier 3d printed. Then I found... http://www.ebay.com/itm/262794713841 Those are even already loaded with erasable 27C256 plus an extra. The same seller also has even more of the same carriers, but loaded with 27C512. Look at this on eBay http://www.ebay.com/itm/262794714066 And unless he wrote the descriptions and titles wrong, each item is a lot of 8 carriers and 9 eproms. And he has at least 8 lots avaialble on each ad. So it's one stop shopping for $7.50! More carriers than you'll ever use, and 9 chances to get a blank eprom that still works to load your new rom on. If you own a 600, I say go grab one of these now. I don't think they are of much use for 100/102/200 owners. They fit, but you have no chips that would work. You need to map the pins to other pins, which means you need a rombo/mombo/figtronix style module. About the only down side is reprogramming a rom after you've curled the legs under the carrier. You can't get a dip28 test clip onto the pins with the carrier in the way. And you don't want to be bending and unbending the legs more than once or twice. What you really need is an empty socket, so you can stick the socket into the eprom programmer, and then pop the carrier in the socket without having to ever bend the pins on any chips. Well I think I might have just bought 100 sockets for $30, so, everyone can have one! All 6 people in the world who this matters to at all... http://www.ebay.com/itm/272343684830 The sockets ARE useful for a 100/102/200 owner. If you stick one of those sockets on a figtronix "programming adapter" board, which just maps the pins from a M100 optrom back to a 27C256 pinout, would make the most convenient way to re-program 100/102/200 opt roms too. So you could generally use 2 of those sockets if you own both 100 and 600 -- bkw On Jan 8, 2017 12:38 PM, "John R. Hogerhuis" <[email protected]> wrote: > Yep I only have multiplan. > > As to option rom I guess 3D printing carrier is an option now. No one has > tried it yet. The approach for a long time has been just been a pcb with > half moon cut through hole vias on the edges with a ribbon glued on to > facilitate extraction. Or REX where it can pretty much stay in permanently > since its reprogrammable in circuit. > > -- John. >
