kim@amdahl.UUCP (01/17/87)
[ "Send lawyers, guns, and money ..." ]
The new issue of Amazing Computing (v2,n1) has a very detailed article (by
Cris Erving) about how to add 512K of memory to the Amiga's motherboard.
Of course it involves a bit of h/w hacking, and would certainly void one's
warranty, but the cost is only about $70 for parts.
Because of the address space where it lives, just above Chip ram in part of
the "reserved" address space, it won't AutoConfig ... you have to use AddMem.
And no, you can't use it as Chip memory, because the custom chips can only
address the lowest 512K ... AmigaDOS sees it as Fast ram (though unlike
expansion bus Fast ram, there *can* be contention with the custom chips
for memory accesses within this 512K). Cris gives the name "Synchronous"
to this kind of ram.
The article also says that there is enough power left over to run things
like Digi-View, or A-Time. I'm wondering if there would be a problem with
having a C.Ltd 1 Meg aMEGA board on the expansion bus, power-wise? Anyone
know if there's a heavy-duty replacement power-supply that has the same
form-factor as the original?
Also, I'm wondering if this mod can be made compatible with the "Kickstart
Eliminator and RAM Expansion Kit" by Creative Microsystems, Inc. that
Jac Colby talked about in a recent posting. This mod wants to live at
x'080000' thru x'0FFFFF', immediately above Chip ram. [Jac ... where does
the WCS end up living after installing the Kit? Can it be moved elsewhere?]
Assuming the Kit and the mod can be made to co-exist addressing wise, there
shouldn't be a problem power-wise, as the Kit is only adding 2 ROM's to
what's already there. Lesee, that would be an extra 768K for about $200,
and a few hours work ... not bad!
Of course when the Amiga XXXX (where XXXX is your favorite rumormill number),
comes out with the Fat-Agnus chip that can address 2 Meg, these are in the
address space she'll want. But then you can't put a Fat-Agnus into an
Amiga 1000 ... or can you ... hmmmmm?
/kim
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[ Any thoughts or opinions which may or may not have been expressed ]
[ herein are my own. They are not necessarily those of my employer. ]jacc@midas.UUCP (Jac Colby) (01/18/87)
In article <5206@amdahl.UUCP> kim@amdahl.UUCP (Kim DeVaughn) writes: > >[ "Send lawyers, guns, and money ..." ] > >The new issue of Amazing Computing (v2,n1) has a very detailed article (by >Cris Erving) about how to add 512K of memory to the Amiga's motherboard. ... >Also, I'm wondering if this mod can be made compatible with the "Kickstart >Eliminator and RAM Expansion Kit" by Creative Microsystems, Inc. that >Jac Colby talked about in a recent posting. This mod wants to live at >x'080000' thru x'0FFFFF', immediately above Chip ram. [Jac ... where does >the WCS end up living after installing the Kit? Can it be moved elsewhere?] After taking a look at the Amiga's memory map, it would seem that the two memory enhancements should be able to cohabitate very nicely. The Kickstart Eliminator and RAM Expansion Kit AddMem's the WCS RAM from x'0F80000 to x'0FBFFFF. The Amiga H/W manual shows the system ROM space to be x'0F80000 to x'0FFFFFF, with the notes: "Development system ROMs located at start address x'0FE0000" and "Final system ROM's will probably be located at start address x'0FC0000". So I assume that the WCS was and still is mapped to x'0F80000 to x'0FBFFFF, and the new ROM's now occupy all of x'0FC0000 to x'0FFFFFF. Now, let's see, if you used 1 meg RAM's in the x'080000 space (even less power draw), and a full 8 meg expansion board, you'd could get 10.75 meg ... but be careful, you might run afoul of the law of diminishing returns. BTW, I'm still very happy with the Kickstart Eliminator and RAM Expansion. I'll be getting the RAM speed benchmark program later today and will report the WCS speed as soon as I can. Jac Colby - they disclaim me around here, too. UUCP: {ucbvax,decvax,pur-ee,cbosg,ihnss}!tektronix!midas!jacc -or- jacc@midas.TEK.COM 5529 SW Patton Rd, Portland, OR 97221 (503) 292-1609 -or- MS 94-442, PO Box 4600, Beaverton, OR, 97076 (503) 629-1129 terrorist cryptography DES drugs cipher secret decode NSA CIA NRO IRS coke crack pot LSD russian missile atom nuclear assassinate libyan RSA The above is food for the NSA line eater. Add it to your .signature and you too can help overflow the NSA's ability to scan all traffic going in or out of the USA looking for "significant" words. (Sadly, this is not a joke.)