idh@NABLA.ELECTRICAL-ENGINEERING.UMIST.AC.UK (Ian D Hawkins) (09/14/89)
I would like to add a 68881 to my ST (to go with my prospero FORTRAN compiler). Is a reasonably priced add on board available, or has the necessary interface circuitry been published anywhere?. The board would probably have to bolt on to the 68000 as the glue chip in my machine is surface mounted. I noticed an odd effect when upgrading the RAM in my ST; it wont allow different sized RAM banks. Bank 0=500k,bank1=2M gives 1Mbyte total, bank 0=2M, bank1=500k gives an apparent 4M and a swift crash!.
chris@tadhg.newcastle.ac.uk (Chris Forker - Nav Arch-) (09/14/89)
I have a board with a 68881 produced by Atari in my Mega. You did not state what machine you have. I got my board from Silica Shop about a year ago for 107 pounds sterling ( ed discount ). If you don't have a Mega, you could consider one of the accelerator boards with a slot to take the 68881. Try Power Computing, or Third Coast Tech. BTW, Pro. Fortran with the 68881 flies. Not much slower on the savage benchmark than a Sun 3/50. The following benchmarks where obtanined using Pro. Pascal. TEST Fib Float Sieve Savage ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ No. Iter. 100 10,000 100 25,000 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Atari ST 303.93 52.06 57.23 518.60 Atari ST (1) 303.93 12.42 57.23 6.37 Mac SE 264.00 229.98 64.70 1884.30 Sun 3/50 * 88 17 10 254 Sun 3/50 (2) 135 2 10 5 Sun 3/60 * 57 11 7 161 Sun 3/60 (3) 94 2 7 4 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Sun 386i + 125 14 27 179 Sun 386i (4) 124 1 27 16 IBM PS/2 50 + 258 28 60 365 IBM PS/2 70 + 140 16 29 200 IBM ATx + 324 35 74 458 IBM ATx (5) 317 11 75 31 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ( ALL times are in seconds ) *:Sun Unix Release 3.5 ( Pascal -no optimization, multi-user, & fsoft) 1:MC68000 @ 8Mhz + MC68881 @ 16Mhz 2:MC68020 @ 15.5Mhz + MC68881 @ 15.5Mhz 3:MC68020 @ 20Mhz + MC68881 @ 20Mhz 2 & 3 used the -f68881 option instead of -fsoft. +:No maths co-processor 4:80387 @ 16Mhz ( I think. The 386i is the 150 variant ) 5:80287 @ 10Mhz All times obtained using the DOS version of Pro. Pascal on IBM's & Sun 386i. 386i was in DOS mode. The time for the Mac SE was found in the July 87 ( I think ) issue of BYTE in an article on benchmarking machines. The same Pascal code was used on all the machines. Although different timing methods were employed in software for each different architecture. The above figures are given in good faith. As with all benchmarks you only get what you want to see. +-=--=--=--=--=--=--=--=--=--=--=--=--=--+--=--=--=--=--=--=--=--=--=--+ | mail: Chris.Forker@newcastle.ac.uk | Dept. Marine Technology | | voice: +44 91 2226000 X 6750 | Newcastle University | | fax: +44 91 2611182 | Newcastle upon Tyne | | | NE1 7RU ENGLAND | +-=--=--=--=--=--=--=--=--=--=--=--=--=--+--=--=--=--=--=--=--=--=--=--+
apratt@atari.UUCP (Allan Pratt) (09/16/89)
The product you want is the Atari SFP004 Floating-Point Math Peripheral or some such name. SFP004 should be sufficient for your dealer to order one if he doesn't already have one. It only goes into Megas; it fits on the internal expansion bus. Of course, on a 68000 you can't talk to it as well as a 68020 can; you have to use it in "peripheral mode" where the handshaking protocol is handled in software, not directly by the CPU. Only programs compiled specifically with the SFP004 in mind will run faster; others won't notice it. (In that respect it is unlike the Blitter.) The SFP004 comes with a disk, I think, containing the guts of a library you can merge with Alcyon's libm to make lib81; link your Alcyon C programs with that library and they will use the SFP004 if it's installed, and Alcyon's software routins if it's not. There is also source for those routines, as examples you can use in assembly language or for other compilers. I *think* that disk is part of the SFP004 package; if it's not, it should be available from Atari. ============================================ Opinions expressed above do not necessarily -- Allan Pratt, Atari Corp. reflect those of Atari Corp. or anyone else. ...ames!atari!apratt
stevef@well.UUCP (Steven Robert Fordyce) (09/21/89)
Creative Microsystems' accelerator for the ST has a socket for a 68881 on it. It connects the 68881 in the same way that Atari does, so it is software compatible with Atari's board. Our product also speeds up the processor and gives you a blitter socket, and it fits all three ST's. The price is $299. Steven R Fordyce uunet!sequent!calvin!stevef Creative Microsystems, Inc., 19552 SW 90th Court, Tualatin, Oregon 97062, USA For customer service, call Lillian Carter at (503)691-2552, FAX (503)691-1292
idh@NABLA.ELECTRICAL-ENGINEERING.UMIST.AC.UK (Ian D Hawkins) (10/13/89)
Thanks for the replies to my posting asking for 68881 add-on
info. The machine I intend adding the coprocessor to is a
recent 1040STFM. It has two ROM chips, surface mounted GLUE
and MMU chips and the 68000 is positioned below the keyboard
space bar. It has been upgraded to 2M ram. I understood a
German company (Lischa Datentechnik, Hochstrasse 22, 4173
Kerken 2) produced a board that was stuck ontop of the 68000,
it sounded suitable, I wrote to them but no reply came. If
any one knows about Lischa & the 68881 please elaborate. I
tried to get a Third Coast CMI accelerator board, ordered it
in june, they cashed the cheque, they still havent sent the
board, despite having advertised its existance for months. I
phoned them, they said 'ready in two weeks' .....four weeks
ago. I am not happy with Third Coast's service.
In reply to Wolfgang Hecht's enquiry about ST
Fortrans, the only Fortran I am familiar with is by Prospero.
It is well documented, has a good debuger, and produces code
that runs 20KWhetstone/s double precision 50KWhetstones single
precision (and 200KWhetstones for both precisions with the
68881). Both single and double precision use the IEEE floating
point format. About the only gripe I have against it is the
rather slow compile and link times and the slow editor screen
manipulation (much improved with turbo ST 1.6).
idh@uk.ac.umist.electrical-engineering.nabla
Ian Hawkins (phone 061-200-4769)
Elec Eng
UMIST
Manchester po box88
England