risto@tuura.UUCP (Risto Lankinen) (01/09/91)
graeme@research.canon.oz.au (Graeme Wong See) writes: >I was recently in a computer store where I saw a brochure for a 386 >motherboard (can't remember if it was a DX or SX motherboard) from Taiwan. >In the specs under coprocessors it says that it can take either a >287 or a 387 maths coprocessor. Is this at all possible with either a DX or SX? >Perhaps it is a typo but any clarification on the matter will be helpful. Hi! It's true; a friend of mine has a Finnish-made Nokia AWS/386 with *2*87, and it runs fine. The socket is a bit peculiar: There are pin holes in square arrangement for 80387, and in two parallel rows for 80287, some of which are shared at the same place. Also, the 287 is 2/3 the frq of the CPU (like 12 MHz <-> 16 MHz) as it often is with 287. I don't know how much speed would be gained by using 387 instead. Terveisin: Risto Lankinen -- Risto Lankinen / product specialist *************************************** Nokia Data Systems, Technology Dept * 2 2 * THIS SPACE INTENTIONALLY LEFT BLANK * 2 -1 is PRIME! Now working on 2 +1 * replies: risto@yj.data.nokia.fi ***************************************
schuster@panix.uucp (Michael Schuster) (01/10/91)
In article <1991Jan9.004654.21586@research.canon.oz.au> graeme@research.canon.oz.au (Graeme Wong See) writes: > >I was recently in a computer store where I saw a brochure for a 386 >motherboard (can't remember if it was a DX or SX motherboard) from Taiwan. >In the specs under coprocessors it says that it can take either a >287 or a 387 maths coprocessor. Is this at all possible with either a DX or SX? Early 386 chips supported the 80287 since at the time there was no 80387. I believe 80287 support was dropped as of the D-step of the 80386, which was about mid 1988. Taiwan, Inc. seems not to care, and goes on happily producing (and advertising) boards with sockets than nobody can use. -- l\ /l ' _ Mike Schuster ...!cmcl2!panix!schuster l \/ l l l/ (_ NY Public Access CIS:70346,1745 l l l l\ (_ UNIX Systems MCI Mail,GEnie:MSCHUSTER
smsmith@hpuxa.ircc.ohio-state.edu (Stephen M. Smith) (01/10/91)
graeme@research.canon.oz.au (Graeme Wong See) writes: > >I was recently in a computer store where I saw a brochure for a 386 >motherboard (can't remember if it was a DX or SX motherboard) from Taiwan. >In the specs under coprocessors it says that it can take either a 287 >or a 387 maths coprocessor. Is this at all possible with either a DX or SX? >Perhaps it is a typo but any clarification on the matter will be helpful. Over Christmas break I rented a 386 computer with this very configuration. When the sales rep told me it had a 287 installed I attempted to correct him by saying that he must mean a *387*, but he said that it did in fact have a *287* on board because the motherboard was socketed for both the 287 and the 387. When I got the computer home I opened it up and sure enough, there was the rectangular 287 on the motherboard and there was a square socket for a 387 to be added as well. I don't know how the 386 chip uses the 287--perhaps this can only be done on a 386sx (I don't remember if this computer was an SX or a DX-20). The motherboard was a *Mylex* believe it or not! S. "Stevie" Smith \ + / <smsmith@hpuxa. \+++++/ " #*&<-[89s]*(k#$@-_=//a2$]'+=.(2_&*%>,,@ ircc.ohio-state. \ + / {7%*@,..":27g)-=,#*:.#,/6&1*.4-,l@#9:-) " edu> \ + / BTW, WYSInaWYG \ + / --witty.saying.ARC
kaleb@thyme.jpl.nasa.gov (Kaleb Keithley) (01/10/91)
In article <1991Jan9.180643.14310@magnus.ircc.ohio-state.edu> smsmith@hpuxa.ircc.ohio-state.edu (Stephen M. Smith) writes: >graeme@research.canon.oz.au (Graeme Wong See) writes: >>I was recently in a computer store where I saw a brochure for a 386 >>motherboard (can't remember if it was a DX or SX motherboard) from Taiwan. >>In the specs under coprocessors it says that it can take either a 287 >>or a 387 maths coprocessor. Is this at all possible with either a DX or SX? >>Perhaps it is a typo but any clarification on the matter will be helpful. > >Over Christmas break I rented a 386 computer with this very configuration. >When the sales rep told me it had a 287 installed I attempted to correct >him by saying that he must mean a *387*, but he said that it did in >fact have a *287* on board because the motherboard was socketed for >both the 287 and the 387. When I got the computer home I opened it >up and sure enough, there was the rectangular 287 on the motherboard >and there was a square socket for a 387 to be added as well. I don't >know how the 386 chip uses the 287--perhaps this can only be done >on a 386sx (I don't remember if this computer was an SX or a DX-20). > Early 386 boards were socketed for both the 287 and the 387 because early production quantities of 387s were very small. These were, and are 386DX boards, the SX didn't even come out for over a year after the DX was shipping in production quantities. -- Kaleb Keithley Jet Propulsion Labs kaleb@thyme.jpl.nasa.gov Offensive quote coming soon to a .signature file near you.
wbeebe@bilver.uucp (Bill Beebe) (01/12/91)
In article <916@tuura.UUCP> risto@tuura.UUCP (Risto Lankinen) writes: > >The socket is a bit peculiar: There are pin holes in square arrangement for >80387, and in two parallel rows for 80287, some of which are shared at the >same place. Also, the 287 is 2/3 the frq of the CPU (like 12 MHz <-> 16 MHz) >as it often is with 287. > >I don't know how much speed would be gained by using 387 instead. In the beginning, when the 80386 was first introduced, Intel did not have the 80387 ready. So they published an ap note that explained how to interface the 80287 to the 80386. Many systems houses did this at first to ship product. Some were foresighted enough to include sockets for both the 287 and 387. The 80287 is currently rated at 10 MHz. max. The 80387 _starts_ at 16 MHz and goes up to 33 MHz. On a 16 MHz 386 system, the 387 will run 3 to 5 times faster than the 287. Part of this is the higher clock, part is the optimized microcode and hardware of the 387. Keep in mind that the 387 has trigonometric functions, and the 287 does not.
c35877f@saha.hut.fi (Jouni M{kel{) (01/23/91)
just testing
Jouni M{kel{ jmakela3@otax "Practice makes perfect.....
Maininkitie 4 D 40 c35877f@saha except with Russian Roulette,
02320 Espoo where practice just makes a mess!"
- Alfred E. Neuman