28-10-2026, 12:31 PM
Hi Shane.
There are some mods to do for a 32k machine to accept a 128k coreboard.
RESET is handled differently between both. The 128k coreboard still uses the Z80 RESET line for it's power-up reset, but
the Keyboard RESET button circuit is then linked to the Processors' NMI line rather than RESET, so that if you hold the RESET button
to get the machine to reboot, a soft reset is triggered. This means that the DRAM refresh continues and the contents of RAM are not lost
during a [Pushbutton] RESET cycle.
If you look in the repository (in perhaps the Hardware Notebook I think) for the Computer-in-a-book upgrade details, it gives you the track cuts & links
to be done.
There are some mods to do for a 32k machine to accept a 128k coreboard.
RESET is handled differently between both. The 128k coreboard still uses the Z80 RESET line for it's power-up reset, but
the Keyboard RESET button circuit is then linked to the Processors' NMI line rather than RESET, so that if you hold the RESET button
to get the machine to reboot, a soft reset is triggered. This means that the DRAM refresh continues and the contents of RAM are not lost
during a [Pushbutton] RESET cycle.
If you look in the repository (in perhaps the Hardware Notebook I think) for the Computer-in-a-book upgrade details, it gives you the track cuts & links
to be done.