(20-12-2019, 08:52 PM)Ernest Wrote:(20-12-2019, 06:05 PM)longi Wrote:The Premium and 256TC already have RTC capability built in and was able to be added to most of the earlier systems with a hardware upgrade.(21-11-2019, 08:38 AM)someone Wrote: The Enhanced Floppy Disk Controller with multiple serial ports and and battery backed Real Time Clock.
This used Signetics 2651 USARTs to provide fully fledged interrupt driven RS232 ports.
An RTC would be awesome. Opens the door to things like https://en.wikipedia.org/wiki/SymbOS
The Alpha Plus(aka Premium) and 256TC were created after the Enhanced Floppy Disk Controller. The Enhanced Floppy Disk controller was not released due to an SRAM shortage and market release of 64K x 1 DRAMs of the time which led to the creation of the more inexpensive 128K DRAM FDC coreboard. The initial coreboards supported both Z80 and TMS4500 DRAM controllers. Since these this new coreboard had a FDC connector and no 50 way expansion connector, the Alpha Plus baseboard was laid with the 50 way expansion connector. There is also a mod board for standard baseboards to have a 50 way expansion connector.
Seasons' Greetings!
Have a safe and festive holiday period.