larryh@tekcbi.UUCP (Larry Hutchinson) (12/18/85)
For the brave & rich hacker:
I just received a data sheet on a mezzanine board containing a 68020
and a 68881 that plugs into a normal 68000's 64 pin dip socket.
The board is 2.5" by 3.2" by 0.3". The price was not given but I
would guess it is steep (>$1000). Those who are interested should
contact:
IO Inc.
2430 N. Huachuca Dr.
Tucson, Arizona 85745
(602) 792-0969
Please note the following possible problems:
1) The mac's 68000 is soldered in. No socket.
2) The exception stacking is different for the 68020. Mac
software may break.
3) The main advantage that the 68020 brings is the higher
clock rate (up to 20MHz) and the 32 bit bus. Neither
is applicable. (But I would love to have the 68881!)
4) It sucks 400ma more than the 68000. One would hope this
is negligible.
5) There may be others.
Also, I suspect that there are many companies making similar products
and that the price may become reasonable in the comming year. If
anyone tries this (and I doubt it!), let the net know.
Larry Hutchinson, Tektronix, Inc. PO Box 500, MS 02-305, Beaverton, OR 97077
{ decvax,allegra }!tektronix!tekcbi!larryhkim@mips.UUCP (Kim DeVaughn) (12/21/85)
> Larry Hutchinson, Tektronix, Inc. writes in net.micro.mac: > > I just received a data sheet on a mezzanine board containing a 68020 > and a 68881 that plugs into a normal 68000's 64 pin dip socket. > The board is 2.5" by 3.2" by 0.3". The price was not given but I > would guess it is steep (>$1000). Those who are interested should > contact: > IO Inc. > 2430 N. Huachuca Dr. > Tucson, Arizona 85745 > (602) 792-0969 I spoke briefly with Tom Sargent (IO Inc's President) ... the '020 that comes on this board is a 12.5 MHz part, but it runs at whatever the original clock rate was (and is restricted to a 16-bit data-path). Price quoted was $1000 w/o the 68881; $1272 with it (quantity of one). Quantity discounts start at the "quantity of two" level ($50 off per board). Availability was said to be 2 weeks, ARO. > Also, I suspect that there are many companies making similar products > and that the price may become reasonable in the comming year. Yes. Computer System Associates (CSA) in San Diego has a similar product available, which has been much discussed on net.micro.amiga. The CSA board is a bit more expensive, but has options for independent clocking and on-board *32-bit* RAM (256K of it, anyway). The IO Inc. board currently has an orientation problem if the installation is in an Amiga ... the board needs to be "offset" from the 68000's socket in the other direction. IO Inc. will be either re-spinning the board to fit, or will offer an "offset board" that would go in-between the 68000 socket and their 68020 daughter-board. The above is provided for information (and wishful thinking) only; I have no connection with either company. /kim -- UUCP: {decvax,ucbvax,ihnp4}!decwrl!mips!kim DDD: 415-960-1200 USPS: MIPS Computer Systems Inc, 1330 Charleston Rd, Mt View, CA 94043