RAM cartridges implementation #184
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…dges. CART monitor command. Make blank cartridge UI option.
Reserved CART file ids for additional cartridge types currently unemulated by Atari800, added also the description of the types.
|
Looks good, can you rebase on master? |
…dges. CART monitor command. Make blank cartridge UI option.
|
I've already made rebase with master on ramcart branch. |
|
Thanks! Most likely it will be me who will check the the Falcon build. :) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Many RAMCART and one SiDiCar battery backed static RAM cartridges.
Preliminary support for writeable cartridges (ought to be useful for #109).
I prepared Ram-Cart (Polish RAM cartridges released by Unerring Masters company and Zenon/Dial scene group) and SiDiCar (RAM cartridge described in Polish magazine "Tajemnice ATARI") support for Atari800.
Ram-Cart is a RAM cartridge using static RAM chips and battery power supply to persist the data written in cartridge.
Whole memory is partitioned to 16KB banks. Control register located at $D5xx page is responsible to current bank selection and enabling visibility of it's lower and higher part in $8000-$9FFF and $A000-$BFFF windows (similar to many standard ROM banking cartridges). Preferred location for such register is $D500 (and $D501 for bigger cartridges).
Ram-Cart was released in many variants:
Beside of amount of RAM, all cartridges differ with number and functions of switches placed on the top of cart case and bank switching ideas.
My implementation of emulation supports:
SiDiCar is a simple 32K RAM cartridge with a control register located on $D5xx ($D5FF is recommended by constructor) but it's using a $8000-$9FFF window only.
Changes made in the code of Atari800:
You can read about Ram-Cart (in Polish only, but I don't know if there are English version anywhere) at:
and there are few Serious 8,9,10,11 disk magazines (in Polish too) where design details and programming techniques are described: http://web.archive.org/web/20100804024148/http://www.serious-dial.atari.pl/zzone/pserious.html
Back in the days Dial Group has released modified version of DOS II+/D supporting RAMCART as D7 and D8 ramdisks:
http://web.archive.org/web/20091210152852/http://www.serious-dial.atari.pl/pliki/softdial/DblRC.zip
Description in Polish is here:
http://web.archive.org/web/20090209232906/http://serious-dial.atari.pl/artykuly/dblrc.html
SiDiCAR was made by Jarosław Krysztopik (vel SEC2692) and is described in Polish at:
Additionally there is Czech cartridge "Raster/C.P.U. S/XEGS 128K RAM-CART" described in English at:
but not implemented by me.