Post by dshadoff on May 6, 2020 21:11:37 GMT
(This is carried over from the "Looking for CD Stupid Card" thread)
I continue to look into improving Chris Covell's PCEMon.
chrismcovell.com/PCEmon/index.html
One prong of the approach is by adding an accelerator board which I introduced in "Personal Projects" here:
pcengine.proboards.com/thread/853/pcemon-accelerator
I'm building out functionality slowly because I've been distracted with other projects lately, but I'll be returning to this soon.
So far, I have only used it with a dedicated cartridge containing only PCEmon... but Chris thought ahead, and was able to create a patched System Card which also has a copy of the monitor program, chained by the <RUN+SELECT> soft reset. He has already explored ways of saving/loading game states on real hardware - although this a somewhat convoluted process in its current state. One of the features I look forward to adding to PCEmon is the ability to make this a single command which is automated by the microcontroller.
Since many of the games which exist today use all the memory available to them, there really isn't any left for the monitor program, without trampling something owned by the game.
So the second prong would be to put some memory in an unused bank:
- For HuCards, these would be any bank from $80 to $F6 (I think).
- For CD-ROM/Super CD-ROM, these would be from $2F to $67 and from $88 to $F6 (I think).
So I thought about creating a memory card, which would need some selection logic (or a CPLD) to map memory to this whole space. In fact, TailChao's CD Stupid Card already did this, but the banking scheme is different, and it doesn't map memory to the upper space.
In the near term, my plan is to reprogram the CPLD to map differently, but longer term I think another board design may be created.
So the overall memory map could look like:
bank $00-$2F = modified system card(*)
bank $30-F6 = RAM (**)
(*) This could take the form of mappable RAM and a boot ROM.
(**) This may need to be definable between $30 and $67, due to potential software conflicts in the $4x range (and Arcade Card).
The monitor program would be loaded somewhere like bank $89-8A, where it doesn't bother any existing programs.
The monitor program would have the whole area from $8B to $F6 for is own temporary storage, copying, test routines, ADPCM payloads to play, etc.
I think this could be kind of fun... anybody else interested ?
I continue to look into improving Chris Covell's PCEMon.
chrismcovell.com/PCEmon/index.html
One prong of the approach is by adding an accelerator board which I introduced in "Personal Projects" here:
pcengine.proboards.com/thread/853/pcemon-accelerator
I'm building out functionality slowly because I've been distracted with other projects lately, but I'll be returning to this soon.
So far, I have only used it with a dedicated cartridge containing only PCEmon... but Chris thought ahead, and was able to create a patched System Card which also has a copy of the monitor program, chained by the <RUN+SELECT> soft reset. He has already explored ways of saving/loading game states on real hardware - although this a somewhat convoluted process in its current state. One of the features I look forward to adding to PCEmon is the ability to make this a single command which is automated by the microcontroller.
Since many of the games which exist today use all the memory available to them, there really isn't any left for the monitor program, without trampling something owned by the game.
So the second prong would be to put some memory in an unused bank:
- For HuCards, these would be any bank from $80 to $F6 (I think).
- For CD-ROM/Super CD-ROM, these would be from $2F to $67 and from $88 to $F6 (I think).
So I thought about creating a memory card, which would need some selection logic (or a CPLD) to map memory to this whole space. In fact, TailChao's CD Stupid Card already did this, but the banking scheme is different, and it doesn't map memory to the upper space.
In the near term, my plan is to reprogram the CPLD to map differently, but longer term I think another board design may be created.
So the overall memory map could look like:
bank $00-$2F = modified system card(*)
bank $30-F6 = RAM (**)
(*) This could take the form of mappable RAM and a boot ROM.
(**) This may need to be definable between $30 and $67, due to potential software conflicts in the $4x range (and Arcade Card).
The monitor program would be loaded somewhere like bank $89-8A, where it doesn't bother any existing programs.
The monitor program would have the whole area from $8B to $F6 for is own temporary storage, copying, test routines, ADPCM payloads to play, etc.
I think this could be kind of fun... anybody else interested ?