ZorRam - new memory board for Zorro 3

[Zac67]

Wowee!

Thought there'd be a way to do a reasonable SDRAM board...

I'm not holding my breath but this definitely is something to look forward to. Very interested to find out the specs: price, speed compared to onboard RAM, availability.

[Zac67]

Just throw a battery on the RAM board and call it done.

(S)DRAM uses quite a bit of power, plus you'll need the controller to continue refreshing. Anything beyond a couple of minutes would increase the price to no-go regions.

[Zac67]

With an adapter would it work with an A500, if it were configured to work in ZII mode?

A slingshot hack should put any ZII bord to use on a 500. But before spending serious amounts of money on it you might want to consider a 1200.

[Zac67]

@Trev

Why don't you just use some readily available & cheap CF card as recoverable 'RAM' disk?

[Zac67]

I like to see a enhanced 512MB version, anyone else ?!

Wonder what the price might be - if they work out the 128 MB for 99€, the 256 MB for... 149€? 179€? Would be really sweet if E3B could include spare CAS lines to piggy-back another set of RAMs later... :hammer:

[Zac67]

Nice! 128mb ram limit in the cpu slot has been conquered! But why not 512mb? that would be easy, as the Z3 bus supports 512mb per slot, buy 2 and you have 1GB! I don't understand however why they just don't add a slot for the RAM, it would be cheaper to buy and SDRAM is very cheap.

Z3 supports up to 1 GB AutoConfig size.

[Zac67]

Hmm, wikipedia says otherwise, oh well!

Hmm - I look into the Zorro3 specs and it says:

These bits indicate the configuration size of the PIC. This size can be
modified for the Zorro III cards by the size extension bit, which is the new
meaning of bit 5 in register 08.
Bits Unextended Extended
[...]
110 2 megabytes 1 gigabyte

[Zac67]

128MB RAM Limit is still there - it means that onboard RAM can't be more than 128MB.

128 MB is the limit of the CPU fast slot ($0800 0000-$0FFF FFFF). Theoretically, Z3 expansion space could hold up to 1792 MB ($1000 0000-$7FFF FFFF). Onboard RAM is limited to 16 MB by Ramsey, but the architecture allows up to 112 MB ($0100 0000-$07FF FFFF).

(sources: A3000 SM, Zorro III specs 1.10)