ambarry@vax1.tcd.ie (Just dial 1-212-976-TART (Brooklyn/Queens/NYC/LI only)) (03/15/89)
Hello, world I want to speed up my 8086 based PC. I've heard of certain chips that one can replace the 8086 with. Can you recommend a good substitute, and answer a few pertinent questions for me ? Questions : 1. Most important. Will I lose any/some/all of the IBM compatibility by changing the CPU ? 2. Is it easy to do DIY style ? 3. Would anyone be interested in a second hand 8086 ? Thanks in advance, Adrian Barry, CS, Trinity College, Dublin Ireland.
jeffery@igloo.Scum.COM (Jeffery E. Sheese) (03/19/89)
This response was sent via email, but as an afterthought reposted for posterity. In article <37386@vax1.tcd.ie> ambarry@vax1.tcd.ie writes: > I want to speed up my 8086 based PC. I've heard of certain >chips that one can replace the 8086 with. Can you recommend a good substitute, >and answer a few pertinent questions for me ? Wnat you want to do is purchase a Zilog V20 processor. You will get about 20% more speed, because most of the basic math instructions use at least half the clock cycles required for the 8086/8088. > 1. Most important. Will I lose any/some/all of the IBM compatibility > by changing the CPU ? No. You will gain the ability to emulate a Z80, should you desire that capability. > 2. Is it easy to do DIY style ? Turn off the PC and remove the cover. Leave the power cord plugged in so that you can use the chassis as ground. Use a flat blade screwdriver to gently rock each end of the 8086 out of the socket. Keep your other hand on the chassis so that your grounded. After you remove the 8086, place it on top of the power supply case so it doesn't get zapped by static. Next, get the V20. New chips always have the pins bent outwards so that they may be held with automated chip insertion equipment. That means that the new chip will not go straight into the socket. You need to place the pins on one side of the chip ON the socket, but not IN. Gently push the chip so that the pins are bent inwards towards the bottom center of the chip. Do this until the pins extend downward at a 90 degree angle from the bottom of the chip. Once this is done, do the same to the other side. Check the positioning of the other chips and place the chip in the same general direction. One end of the chip will have a small notch or indentation. This should be pointing in the same direction of the motherboard as the other chips. This side is where pins 1 and 40 are located. Once the chip is in position, insert it into the socket. Before turning on the machine, inspect the pins on the chip CLOSELY to make sure that all pins are seated in the socket. When inserting a chip into a socket by hand, sometimes the pins bend under the chip instead of seating into the socket. If this happens to you use a small pair of needle nose pliers to straighten the pins and try again.
wcs@skep2.ATT.COM (Bill.Stewart.[ho95c]) (03/20/89)
In article <1248@igloo.Scum.COM> jeffery@igloo.UUCP (Jeffery E. Sheese) writes: :In article <37386@vax1.tcd.ie> ambarry@vax1.tcd.ie writes: :> I want to speed up my 8086 based PC. I've heard of certain :>chips that one can replace the 8086 with. Can you recommend a good substitute, :What you want to do is purchase a Zilog V20 processor. You will get about **WRONG** The V20 is a replacement for the 8088. The V30 is the replacement for the 8086. V20/8088 uses 8-bit bus, V30/8086 uses 16. This replacement is commonly done in AT&T 6300 PCs, and it supposedly makes major speedups in Microslow Windows and s few other programs, particularly those that do lots of integer math. There are a few compatibility problems, caused by the upgraded instruction set. It seems some programs want to know whether they're running on a PC or AT, so they try a few 80286 instructions to see what happens. Well, the V30 can do those instructions, so the program decides it's on an AT, and goes of into limbo-land because it isn't. The major offendor is the driver for an AT&T expansion memory board. Other than that, you're ok, and if it doesn't work you've only spent $20. -- # Bill Stewart, AT&T Bell Labs 2G218 Holmdel NJ 201-949-0705 ho95c.att.com!wcs # Synchronicity is when the paper has an article about Moonie ties to # Right Wing Politicians, and they're dropping the charges against Ollie North, # and you finally find that copy of "Illuminatus!"
zmacv39@doc.ic.ac.uk (A D Hebblewhite) (03/21/89)
In article <1248@igloo.Scum.COM> jeffery@igloo.Scum.COM (Jeffery E. Sheese) writes: In article <37386@vax1.tcd.ie> ambarry@vax1.tcd.ie writes: > I want to speed up my 8086 based PC. I've heard of certain >chips that one can replace the 8086 with. Can you recommend a good substitute, >and answer a few pertinent questions for me ? Wnat you want to do is purchase a Zilog V20 processor. ^^ If you really do have an 8086 besed machine (as opposed to 8088 for the majority of PC clones) then what you want is the V30, which is a replacement for the 8086. The V20 is intended to replace the 8088. As far as I know these chips are (were) made by NEC, not Zilog, but I may be wrong. Some time ago Intel sued NEC, claiming that their chips ripped off bits of the 8088/8086. Hope this is helpful. -- Adam email: zmacv39@doc.ic.ac.uk snail: Adam Hebblewhite, Department of Computing, Imperial College, London quote: "I'm not a number, i'm a free man!" - The Prisoner disclaimer: This message is mine personally and does not constitute Department : of Computing, policy, opinion etc.
markz@ssc.UUCP (Mark Zenier) (03/21/89)
In article <1248@igloo.Scum.COM>, jeffery@igloo.Scum.COM (Jeffery E. Sheese) writes: > In article <37386@vax1.tcd.ie> ambarry@vax1.tcd.ie writes: > > > I want to speed up my 8086 based PC. I've heard of certain > >chips that one can replace the 8086 with. > > Wnat you want to do is purchase a Zilog V20 processor. The 8088 replacement is the V20 (uPD70108), the 8086 replacement is the V30 (uPD70116) from NEC. > > 1. Most important. Will I lose any/some/all of the IBM compatibility > > by changing the CPU ? Some copy protect schemes may not like the speedup. Good riddance. > No. You will gain the ability to emulate a Z80, should you desire > that capability. Unless there is a newer version, all you get is the 8080 instruction set. One of the CPM emulator packages (Accelerate 8/16) could use this. Mark Zenier uunet!nwnexus!pilchuck!ssc!markz markz@ssc.uucp uunet!amc! uw-beaver!tikal!
cs3b3aj@maccs.McMaster.CA (Stephen M. Dunn) (03/21/89)
In article <1248@igloo.Scum.COM> jeffery@igloo.UUCP (Jeffery E. Sheese) writes: >Wnat you want to do is purchase a Zilog V20 processor. You will get about ^^^^^ Actually, the V20 was designed by NEC; perhaps Zilog now makes them under a second-source arrangement. Note that the V20 is a replacement for the 8088; those of you who are considering upgrading one of the later PC compatibles which uses the 8086 would want a V30. Like the 8088/8086, they use the same instruction set; the difference is that the V30 has a 16-bit data bus and the V20 is 8 bits.
johnl@ima.ima.isc.com (John R. Levine) (03/21/89)
In article <1248@igloo.Scum.COM> jeffery@igloo.UUCP (Jeffery E. Sheese) writes: >>I want to speed up my 8086 based PC. ... >What you want to do is purchase a Zilog V20 processor. ... Actually, it's not made by Zilog, it's made by NEC. The V20 replaces an 8088, the V30 replaces an 8086. Depending on who you ask, the speedup might be 5% or might be 30%. The Norton SI program reports a huge speed improvement but that's because SI mostly tests the speed of multiplication and division and the V20 happens to speed that up quite a lot. -- John R. Levine, Segue Software, POB 349, Cambridge MA 02238, +1 617 492 3869 { bbn | spdcc | decvax | harvard | yale }!ima!johnl, Levine@YALE.something You're never too old to have a happy childhood.