C) Parallel-Bus-Devices:

C) Parallel-Bus-Devices:
(600XL/800XL = parallel bus, XE = cart-port + ECI and/or adapter)

- Turbo Freezer XL Bernhard Engl 256k
4000-7FFF 2,3,4,5,6 B ($D301)
Banks: E3,E7,EB,EF,93,97,9B,9F,A3,A7,AB,AF,B3,B7,BB,BF;
Notes: The Turbo Freezer XL is an external device for the XL-PBI
with its own Operating-Sytem. It has a built-in Freezer, Monitor
and DOS. The Antic access for the RD can simply be built with one
wire from CPU to PBI. The RD Access works with Port-Bits 2,3 for
Bank Switching, Bits 4,5 for Groups and Bit 6 for "Mode-Select".
PortB D7 = Selftest (0=on)
D6 = Mode (1 = XE, 0 = Groups)
D5 = XE: ANTIC-Access (0 = on), Groups: Group H
D4 = XE: CPU-Access (0 = on), Groups: Group L
D3 = Bank Number H
D2 = Bank Number L
D1 = BASIC ROM (0 = on)
D0 = OS ROM (0 = off)
Atari Basic: YES! XL/XE Selftest: YES! Antic access: optional;