Greetings all, There have been many cases where people pick up 8300s off of eBay that were used in some industrial setting and had their original System ROM removed, and a custom application installed in its place. This meant that the machine was useless as a Model T unless you replaced the custom application with a Model T image of some kind.
But as the original NEC PC-8300 used 28-pin masked 128K ROM and there isn't a pin-for-pin compatible 28-pin 128K EPROM in existance, the typical solution was to burn a 32K EPROM containing an 8201A image. That got you a working NEC PC-8300, but without the extra "goodies " that an original 8300 system ROM would give you, such as the TEXT & TELCOM enhancements and the support for the optional internal 300 baud modem. Well as of tonight, I now have the ability produce full 128K replacement EPROMs for a native NEC PC-8300 machine. It's a slightly modified 32-pin EPROM (and by modified, I mean certain pins jumped together) that will fit into your 28-pin socket inside the PC-8300. I've known about the solution for a while, but I didn't have an EPROM burner that could handle this type of chip (NEC 27C1000 or Hitachi HN27C301) until recently. And so I burned a Y2K-fixed 8300 ROM with some of my other little mods, did the necessary wiring of certain pins on the chip, and plugged it into an 8300. Viola! Worked great. By the way I've also got a lead on a 28-pin PROM (write once, no erase window!) that will require no modifications at all after programming it. That would be the "official" chip that can be produced for an 8300 without any soldering or other special handling. Anyway, if anyone finds themselves in the situation where you got one of those industrial 8300s with an app-specific system ROM, and you want a fully functioning 8300 with all the bells and whistles as it should be, you can either follow the instructions at the following link, or just contact me and I'll build you one for my cost. http://www.web8201.net/default.asp?content=/Files/LIBRARY_web8201/NECPC8300_System_ROM_EPROM_Replacement.html Cheers, Gary Weber www.Web8201.com -- Gary Weber [email protected]
