Thanks Jeff. The diagnostic cartridge has RAM in it as well (so 4x 2114 and 2x ROM). I assume the RAM is @ $0000 and the ROM is movable, but I'm not sure. I may wind up having to order that if I can't find something suitable on this side of the pond. Thanks! Rich -- Rich Cini http://www.classiccmp.org/cini http://www.classiccmp.org/altair32 On 12/24/20, 1:50 PM, "vcf-midatlantic on behalf of Jeff Salzman via vcf-midatlantic" <vcf-midatlantic-bounces@lists.vcfed.org on behalf of vcf-midatlantic@lists.vcfed.org> wrote: These are fairly cheap... https://www.thefuturewas8bit.com/shop/cartridges-pcbs/vic-8k-16k-pcb.html On Thu, Dec 24, 2020, 1:45 PM Richard Cini via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote: > First off, Happy Holidays to everyone on the list! > > > > I’m working on a VIC20 project and I know there is a Commodore-issued > VIC20 diagnostics cartridge (I found the ROMs and instructions), but I > haven’t found a schematic for the board, or blanks. I know Tynemouth > Software in the UK used to make/sell them, but they no longer seem to have > them. Does anyone have a schematic? I figure it’s probably similar to a > RAM/ROM cartridge, but I didn’t know the addresses for the RAM. ROM I > assume is the usual 8K blocks. > > > > Thanks! > > > > Rich > > > > -- > > Rich Cini > > http://www.classiccmp.org/cini > > http://www.classiccmp.org/altair32 > > > >