There is no such guide. The Atom does not have any standard structure like the Beeb and Electron. There are no language ROMs or service ROMs.
There are three common ways of initiating a ROM:
1. By generating an IRQ on reset, like the Econet and AtoMMC do
2. By linking to an address, the Program Power Toolbox uses this
3. Most common for Basic expansion, a check byte of #40 at #A000 and #BF at #A001 followed by a (jump to) a statement interpreter.
I am happy to explain more of the third method later this week when I am at a better keyboard then my iPad.
PS: if you want to start immediately you can use http://acornatom.nl/hardware/atinpc/html/pcutil.htm for inspiration.
There are three common ways of initiating a ROM:
1. By generating an IRQ on reset, like the Econet and AtoMMC do
2. By linking to an address, the Program Power Toolbox uses this
3. Most common for Basic expansion, a check byte of #40 at #A000 and #BF at #A001 followed by a (jump to) a statement interpreter.
I am happy to explain more of the third method later this week when I am at a better keyboard then my iPad.
PS: if you want to start immediately you can use http://acornatom.nl/hardware/atinpc/html/pcutil.htm for inspiration.
Statistics: Posted by roland — Sun Apr 28, 2024 11:13 pm