Custom adaptation of the Timex/Sinclair 1000 ROM for the Lambda 8300 computer.
Adapted by Fred Nachbaur, the replacement EPROM came in a 2764, a 28-pin device (several additional pins were necessary for programming EPROMs). The PC8300 ROM was a 24-pin 8K ROM. In order to fit the replacement EPROM to the PC8300, several pins were bent up and connected, and the EPROM was placed in a 24-pin socket.
The images below show the PC8300 ROM with and without socket.
How to make a modern replacement
You’ll need:
- a modern equivalent of the 2764 EPROM, like the 28C64
- a socket adapter to convert the 28 pin EEPROM to the 24 pin socket in the 8300
- EEPROM programmer
Download the binary image (below) and burn it to the 28C64. Configure your adapter and insert in the 8300.
Related Content
- A Letter From Fred Nachbaur (concerning the PC8300 "Timex Clone") (article)
- Incredible Add-On Device Turns TS1000, ZX81 and PC8300 Into Versatile and User Friendly Computers (article)
- Inside the PC 8300 (article)
- More on the PC8300 (article)
- PC8300 "Timex" ROM Documentation (document)
- Silicon Mountain Computers catalog (document)
- The Musical PC8300 (article)
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