Post - Forum - Plus/4 World



	Home Search Games Tapes Covers Cheats Maps Software New Stuff Hall Of Fame HVTC Game Endings Solutions Remakes Publications Magazines Effects Top List Members Groups Features Plus/4 Encyclopedia Hardware Tools Options Forum Home Search Games Tapes Covers Cheats Maps Software New Stuff Hall Of Fame HVTC Game Endings Solutions Remakes Publications Magazines Effects Top List Members Groups Features Plus/4 Encyclopedia Hardware Tools Options Forum	Login

Forum Help

Post Your Message

Previous Messages

Posted By

MCes
on 2019-10-10
09:13:02

Re: Expansion port pin

@SVS
Don't make confusion: "LOW" and "HIGH" are not referred to the logic level, but at which slice of memory maps they are representing...
Historically each "selecting line" is always (normally) active on low logic level, than it can be directly connected to /CS of the relative ROM chip:
ROM can be internal (function low, function high, basic, kernal) or external (Roms inside the cartridge as games or SW tools..).

Posted By

SVS
on 2019-10-09
14:06:29

Re: Expansion port pin

Thank you for the replies.
But looking at http://www.zimmers.net/anonftp/pub/cbm/schematics/computers/plus4/Plus_4_Technical_Docs.pdf page 23: on the table there are C2HI and C2LOW too. In the explainations (bottom) are cited /C1LOW and C1HI.

Posted By

MCes
on 2019-10-09
13:17:47

Re: Expansion port pin

it's /C1LOW (when it's "0" indicte an C1LOW access)

Posted By

gerliczer
on 2019-10-09
13:14:44

Re: Expansion port pin

Most, if not all, control signals are low active as the system is designed with NMOS ICs. C1 Low should be too.

Posted By

SVS
on 2019-10-09
12:28:31

Expansion port pin

A simple question: pin B of the expansion port is C1LOW or /C1LOW (negate)?
Over zimmer.net I see that, for a typo, there are both these descriptions.