Apple-2-HW/TommyPROM
2
0
Fork 1
mirror of https://github.com/TomNisbet/TommyPROM.git synced 2024-12-21 18:30:09 +00:00
Code Issues Projects Releases Wiki Activity

update 2316 page

Browse Source
This commit is contained in:
Tom Nisbet 2024-04-12 17:41:57 -04:00
parent 3f0384959c
commit 885ddca83a
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
docs/_docs/ref-300-2316-2332-roms.md
View File

@ -12,7 +12,7 @@ The 2316 is a 2Kx8 mask-programmable ROM made by Commodore. Intel made a versio
The 2316, 2332 and 2364 ROMs are somewhat unique because they have Chip Select signals that are configured when the data is mask-programmed. Manufacturers could order a 2316 configured with any of its three Chip Select signals as either active-high or active-low.
This causes a bit of confusion, because the datasheets state that the chips are compatible with standard EPROMs, but they should really state that the chips __can be__ compatible, depending on the configuration selected. For example, a 2316 is only compatible with a 2716 if it was manufactured with *CS1* and *CS2* configured active-low and *CS3* configured active-high. Otherwise, some signals will need to be inverted to swap out a 23 serial chip with a more standard EPROM.
This causes a bit of confusion, because the datasheets state that the chips are compatible with standard EPROMs, but they should really state that the chips __can be__ compatible, depending on the configuration selected. For example, a 2316 is only compatible with a 2716 if the 2316 was manufactured with *CS1* and *CS2* configured active-low and *CS3* configured active-high. Otherwise, some signals will need to be inverted to swap out a 23 serial chip with a more standard EPROM.
Some systems will contain multiple 23xx chips with the Chip Selects configured the same and others will configure each chip differently. For example, some 8K Atari cartridges use two 2332 chips and will invert one of the Chip Selects so that either chip can be selected with a single address line to differentiate them. If the chips are removed from the cartridge, they would need different Chip Selecct wiring to read their data.