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68000 68030 CPLD FPGA ARM
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Memory-2 Board - Custom ROMS
Running your own program code automatically when power is applied requires the creation of a Custom ROM.

The Custom ROM must contain code to bring the system up as well as code to reset/initialise any programmable I/O devices prior to use.

 
 
Memory-2 Boot ROM's
 
For systems with 256KB ROM, 2MB RAM, & ACIA @ $F10040
 
The Custom ROM replaces the System ROM (IC6) and so the lower half of the Custom ROM resides in memory at FC0000-FFFFFF, the upper half is unused and unaddressable.
 
Board Settings:
 
Memory-2 Board JB1 pins 5-6 short, J1 open, 27C4096 ROM, gal8 firmware
Hex Display Board DS1=AB
Dual 6850 Board DS1=F1, J1 pins 2-3 short
 
custom_rom_example1 Bare Metal Programming - System Startup
  The system boots-up and then displays "12340000" shortly followed by "00005678" on the Hex Display Board.
   
custom_rom_example2 Dual 6850 Board - ACIA Setup + Serial Transmission
  Sends "Hello World" to a PC terminal attached to the CON (TERM) Port.
 
 
Modified Memory-2 Boot ROM's
 
For systems with 4MB ROM, 8MB RAM, & ACIA @ $AC0000
 
Board Settings:
 
Memory-2 Board JB1 pins 3-4 short, J1 open, 27C322 ROM, gal8e firmware
Hex Display Board DS1=AB
Dual 6850 Board DS1=AC, J1 pins 1-2 short
 
 
custom_rom_example1b Bare Metal Programming - System Startup
  The system boots-up and then displays "12340000" shortly followed by "00005678" on the Hex Display Board.
   
custom_rom_example2b Dual 6850 Board - ACIA Setup + Serial Transmission
  Sends "Hello World" to a PC terminal attached to the CON (TERM) Port.
 
 
Modified Memory-2 Boot ROM's
 
For systems with 4MB ROM, 8MB RAM, & DUART @ $AA0000
 
Board Settings:
 
Memory-2 Board JB1 pins 3-4 short, J1 open, 27C322 ROM, gal8e firmware
Hex Display Board DS1=AB
68681 Board DS1=AA, J1 pins 1-2 short
 
 
custom_rom_example3b 68681 Board - DUART Setup + Serial Transmission
  Sends "Hello World" to a PC terminal attached to the CON (TERM) Port.
   
custom_rom_example4b 68681 Board - CON (TERM) Port Serial I/O
  Sends "Listening" to a PC terminal attached to the CON (TERM) Port. All characters received on this port are transmitted back to the attached PC terminal. If a CR (Carriage Return) is transmitted, a LF (Line Feed) is also transmitted.
 
 
Disclaimer
All hardware designs, software, and information shared on this website is provided "as is"
without warranty of any kind and strictly for personal non-commercial use only.
 
 
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