Today I'll be talking about how to operate this system, since Part 1 already went in depth on what hardware and modifications were required.
Below is a table covering basic operation of the system in order to select what OS you want active, and if desired, what Language SLOT you want selected as well.
As can be seen the original L1 and L2 LEDs have been reassigned to indicate whether a SLOT or Cartridge is inserted (L1), or what OS is in play (L2). When SHIFT is added to any one of the selection hot keys, it simply modifies which OS is to be used, by selecting the 2nd bank of the OS EEPROM, with the first bank holding the default OS.
Note: The last selection that you make is stored in non-volatile EEPROM memory, and restored upon the next power-up of the system - resuming where you left off.
Below is a table covering basic operation of the system in order to select what OS you want active, and if desired, what Language SLOT you want selected as well.
As can be seen the original L1 and L2 LEDs have been reassigned to indicate whether a SLOT or Cartridge is inserted (L1), or what OS is in play (L2). When SHIFT is added to any one of the selection hot keys, it simply modifies which OS is to be used, by selecting the 2nd bank of the OS EEPROM, with the first bank holding the default OS.
Note: The last selection that you make is stored in non-volatile EEPROM memory, and restored upon the next power-up of the system - resuming where you left off.
SELECT |
STOCK 1200XL Keyboard |
Optional PS/2 Keyboard |
LED L1 |
LED L2 |
SLOT 1 + OS 1 |
F1 |
ALT+F1 |
ON |
ON |
SLOT 2 + OS 1 |
F2 |
ALT+F2 |
ON |
ON |
SLOT 3 + OS 1 |
F3 |
ALT+F3 |
ON |
ON |
SLOT 4 + OS1 |
F4 |
ALT+F4 |
ON |
ON |
NO SLOT + OS 1 |
OPTION+F1 |
ALT+ESC |
OFF |
ON |
+ OS 2 |
ADD SHIFT |
ADD SHIFT |
NO CHANGE |
OFF |
To make this concept a bit easier to understand, I did a short demonstration video of the system in action.
Keep in mind that any two Atari 8-Bit OS variants can be used. So for instance you could have OmniView 80 in one bank and the stock XL/XE in the other. Same goes for the Language EPROM, where any combination of four 8K language, application, and/or games could be pre-programmed.
This is what I have in my test EPROMS at the moment.
32K Dual OS (27C256 EPROM)
Each time a new selection is made, a Cold Restart (similar to Bob Woolley's FREEZER) is initiated in order to reboot into the new configuration without requiring a power cycle of the computer. Whereas the SIO 5V/Ready signal is power cycled to reboot something like an SDrive sitting on that serial bus.
This is all perfectly timed, and happens automatically in the background when changing selections.
I think that covers it for today, but stay tuned, because there might be a Part 3 if I decide to get into how the code in the TKII-PB1200's PIC chip performs some of this magic.
- Michael
This is what I have in my test EPROMS at the moment.
32K Dual OS (27C256 EPROM)
- OS 1 = HSIO patched XL/XE (default)
- OS 2 = Stock XL/XE (selected with SHIFT) I changed this to OmniMon XL, and it works great!
- SLOT 1 = BASIC RevC
- SLOT 2 = Altirra BASIC
- SLOT 3 = Assembler/Editor
- SLOT 4 = SpeedScript
Each time a new selection is made, a Cold Restart (similar to Bob Woolley's FREEZER) is initiated in order to reboot into the new configuration without requiring a power cycle of the computer. Whereas the SIO 5V/Ready signal is power cycled to reboot something like an SDrive sitting on that serial bus.
This is all perfectly timed, and happens automatically in the background when changing selections.
I think that covers it for today, but stay tuned, because there might be a Part 3 if I decide to get into how the code in the TKII-PB1200's PIC chip performs some of this magic.
- Michael
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