ZorRam - new memory board for Zorro 3

[Trev]

@Trev

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

Actually, I use readily available and cheap x86-compatible hardware for all my mainstream computing tasks, but that's not the point.

Having a battery on the RAM expansion could have other productive uses. A safe write-back disk cache is a good example; however, Amiga users are accustomed to powering off at will. Despite the performance gain, a write-back cache wouldn't be well accepted. It would have to be done as a caching disk controller with a soft power interface and firmware logic to manage cache flushes on startup and shutdown.

[spirantho]

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.

128MB RAM Limit is still there - it means that onboard RAM can't be more than 128MB. This is a Z-III card so is limited by the Zorro III address space (up to a Gig or something, not the CPU limit.
The B2000 only has an 8MB limit on the Z-II space, not the CPU slot. Hence accelerators can have more than 8MB happily.

It should be re-iterated that this card will not be supported by AmigaOS 4 - which is, ironically, exactly where it's most needed.... but it's just not practical. It'd be too slow for the PPC, and it'd require more work on the Classic version of the OS, which they're not updating any more.

For OS 3.9 users, though, it's a God-send... so good work to all concerned!

[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)

[Effy]

On the german site Michael Boehmer wrote : "Bei einem 5EUR-Riegel von eb*y aus unbekannter taiwanesischer Quelle mit SDRAMs wechselnder Brands ist dem nicht so - und das Risiko, daß damit laufend Probleme und damit Support anfällt, ist für uns nicht tragbar.

Michael"

Roughly translated it sounds a bit like : "With a 5 Euro memory module of Eb*y, from unknown Taiwan source with SDRAMs with different names, it is not that like that - and the risk that thereby constantly problems and thus support results, is not bareble for us."

Please don't shoot me for the translation

[omnicron10]

Has this board been tested in a Elbox A4000 Mediator Tower bus board?

[HammerD]

Has this board been tested in a Elbox A4000 Mediator Tower bus board?

It says on the AmigaKit site it was tested with Mediator A4000D and A4000Di...so yes, probably will work fine with your Mediator.

I bit the bullet and ordered two ZorRam cards - they should arrive next week, I will post unboxing pix.