Print Page - CPC 1MByte RAM Expansion/GPIO (PLCC84)

Title: CPC 1MByte RAM Expansion/GPIO (PLCC84) - BoM HELP!
Post by: andymccall on 18:00, 24 July 24

Hi,

I've dug out my Amstrad CPC 6128 and restored it and thought I'd build some accessories for it. I've ordered some PCB's for this card here:

https://github.com/revaldinho/cpc_ram_expansion/tree/master/cpc_ram_expansion1mb/releases/rc-3-canberra

I didn't realise the author of the card doesn't recommend building it because the XC9572PC84 is hard to get :picard2: , but I've got 10 PCB's now so I might as well try and build them :P . There's no Build of Materials (BoM) listed, so I've been looking at the other cards in the repo to try and to work out what I need to build it. So far I've got this:

https://www.digikey.co.uk/en/mylists/list/1DLY86MQVF

However there's still a few parts I don't know about. The GPIO header (not sure of the pitch), the C22UF capacitor and the TESTPT connector (I think this is a white connector with a clip on it) and the component under the DIP switches, not sure what it is. I can still see XC9572PC84AEM's on eBay

Can anyone help identify the last few components that would be suitable for this card?

If I can get a list together, build and test them I should have a few spare for others.

Thanks,

Andy

Title: Re: CPC 1MByte RAM Expansion/GPIO (PLCC84) - BoM HELP!
Post by: retro space on 20:55, 24 July 24

Maybe you can get inspiration from this:
https://github.com/ifilot/p2000t-ram-expansion-board/blob/master/img/ram_expansion_board_1056_05.png
It is a 2080kB RAM expansion for the Z80 computer P2000T.
It has no difficult to get components.

Title: Re: CPC 1MByte RAM Expansion/GPIO (PLCC84) - BoM HELP!
Post by: McArti0 on 21:22, 24 July 24

https://github.com/revaldinho/cpc_ram_expansion/wiki/'Old-School'-CPC6128-512KB-and-1MB-RAM-Expansion-Cards

maybe without CPLD?

Title: Re: CPC 1MByte RAM Expansion/GPIO (PLCC84) - BoM HELP!
Post by: andymccall on 09:03, 25 July 24

Quote from: McArti0 on 21:22, 24 July 24https://github.com/revaldinho/cpc_ram_expansion/wiki/'Old-School'-CPC6128-512KB-and-1MB-RAM-Expansion-Cards

maybe without CPLD?

I've already had the cards delivered. If I can't build this, my backup plan was to build that one, but I'd like to at least try and work out what I need.

Title: Re: CPC 1MByte RAM Expansion/GPIO (PLCC84) - BoM HELP!
Post by: eto on 12:56, 25 July 24

Depending on your (de)soldering skills you could also try an internal upgrade to 320 or 512K:

https://www.cpcwiki.eu/index.php/CPC_6320_/_CPC_6512_-_internal_320K_/_512K_for_CPC_6128

Quote from: andymccall on 09:03, 25 July 24I've already had the cards delivered. If I can't build this, my backup plan was to build that one, but I'd like to at least try and work out what I need.

how much will you pay for the CPLD? not sure if it's really worth it to insist on those PCBs.

Title: Re: CPC 1MByte RAM Expansion/GPIO (PLCC84) - BoM HELP!
Post by: Rabs on 17:47, 25 July 24

Don't know if this helps.

Have a look in the net list in the repository for the SIL value cpc_ram1m_plcc84.v (https://github.com/revaldinho/cpc_ram_expansion/blob/master/cpc_ram_expansion1mb/releases/rc-3-canberra/cpc_ram1m_plcc84/cpc_ram1m_plcc84.v)

But if you have a 6128 I would go with the old school version which just requires 74 series logic.

Have you got an expansion card and cables?

CPCWiki forum

General Category => Amstrad CPC hardware => Topic started by: andymccall on 18:00, 24 July 24