I try to summarize the changes from EP128:
-onboard EXDOS
-4MHz Z80A replaced to 6MHz Z80B
-8x1 bit RAM ICs replaced with 2x4 bit ICs as Video memory
-EXOS ROM socket still 32K
-cartridge port removed, replaced by onboard cartridge ROM socket, but it is only 32K
-2 additional 32K ROM sockets
-external System Bus connector and the internal EXP1&EXP2 connectors removed, replaced by Internal System Bus connector
-internal RAM expansion have 256Kbit ICs instead the old 64Kbit ICs. Then the total memory are 320K (64+256)
-PAL video ICs and RF modulator removed (but you can see the place for these on the prototype PCBs), RGB monitor output with 15 pin DA-15S connector, ond monochrome output on RCA
-internal spekar replaced with bigger one (Why not removed?
![ds_icon_rolleyes :roll:](/Smileys/phpbb/ds_icon_rolleyes.gif)
)
-REM2 removed. REM1 controled by both REM1 and REM2 signals
-Serial/Lan connector only kept for Enterprise LAN. Connector replaced to DIN socket
-new hw Serial port added on same PCB with the RAM expansion. It is built with Z80 SIO. But the new SERIAL: driver need to be written.
-Printer connector replaced with 14 pin IDC connector
-Control Port 2 removed, Control Port 1 connector replaced with 10 pin IDC connector.
-keyboard replaced by modified PC keyboard, but still using membrane. Membrane connectors are same with the old.
-power LED moved to the power connector, the light can be viewable at the speaker holes
-planned new external PSU which also generate +12V and -5V. But the kept the +5V regulators in the machine
![ds_icon_rolleyes :roll:](/Smileys/phpbb/ds_icon_rolleyes.gif)
This change only on schematic, the existing prototype borads using the old PSU