Tim Wescott <seemywebsite@myfooter.really> Wrote in message:> On Wed, 21 Dec 2016 11:03:57 -0800, yassilis00 wrote: > >> On Wednesday, December 21, 2016 at 8:09:20 PM UTC+2, Tim Wescott wrote: >>> On Wed, 21 Dec 2016 07:36:22 +0200, Vassilios Spiliopoulos wrote: >>> >>> > Marcel Mueller <news.5.maazl@spamgourmet.org> Wrote in message: >>> >> On 20.12.16 23.07, Vassilios Spiliopoulos wrote: >>> >>> I have an msx 2 machine from 1986. >>> >>> I bought new Zilog z80 CPUs that are 10x faster than what the >>> >>> original ones are are I am thinking to replace them. >>> >>> What will happen? >>> >> >>> >> Nothing. >>> >> It will run at the clock speed of the attached crystal as before. >>> >> >>> >>> Some people told me that my computer will become >>> >>> a complete speed demon. >>> >>> I would like your opinion >>> >> >>> >> They are wrong. >>> >> >>> >> Running at significantly higher clock rate would require changes to >>> >> the circuit and maybe also changes to the software for I/O drivers. >>> >> >>> >> >>> >> Marcel >>> >> >>> >> >>> > So, the circuit will have to be modified in order to install that? >>> > That computer's integrated OS is Microsoft BASIC. >>> > So all applications and games for it are on .Bas format and on >>> > waveform when in cassettes. >>> > All these software were designed to run on a Zilog z80 @ 2.5mhz. My >>> > new Zilog z80 is on 20 mhz. >>> > So I guess that it will load faster? >>> > What changes it might need? >>> >>> So, here's the deal: >>> >>> If you just put the chip in and don't change anything else, then >>> there's a good chance that it'll work the same. Maybe a bit faster if >>> the new Z80 makes more efficient use of clock cycles, but probably the >>> same. >>> >>> You could boost the clock speed to 20MHz with appropriate changes to >>> the oscillator circuit, but it's almost certain that your external >>> memory and peripherals won't be able to keep up, because they're from >>> the same era and price class as that 2MHz CPU. >>> >>> Even if you could just change the clock circuit, then you'd probably >>> mess up whatever real-time aspects of the computer are there. This >>> might be limited to the time-of-day clock going through an hour in 8 >>> minutes, but if the thing generates video it might mean that your video >>> will be totally screwed up. That computer's from an era where pauses >>> in execution were timed by software delay loops, and those would be >>> screwed up as well, so there's a good chance that any games would be >>> screwed up. >>> >>> If you had some significant circuit design and software chops, and you >>> had access to the original software, then you could make the change -- >>> but you'd essentially be redesigning the whole computer. There's a >>> good chance that even if you could get all the right parts that would >>> fit in all the right holes on the board that you'd run into board >>> limitations. >>> >>> Sorry to be so negative. If you want to try it out, go ahead. You'll >>> learn something, and that's always worthwhile. >>> >>> -- >>> Tim Wescott Control systems, embedded software and circuit design I'm >>> looking for work! See my website if you're interested >>> http://www.wescottdesign.com >> >> I see. >> What I was afraid of was if I risk anything, for example if I risk to >> destroy the computer...We are talking about rare stuff... > > If the chip is soldered in and things work now, I would strongly suggest > that you leave it alone. Particularly if the board has plated-through > holes (it almost certainly has two or more layers) then it takes > considerable expertise to get the chip out without damaging the board. > > -- > > Tim Wescott > Wescott Design Services > http://www.wescottdesign.com > > I'm looking for work -- see my website! >Yes, the CPU is soldered -- ----Android NewsGroup Reader---- http://usenet.sinaapp.com/
CPU replacement on a MSX II
Started by ●December 20, 2016
Reply by ●December 23, 20162016-12-23
Reply by ●December 23, 20162016-12-23
On Fri, 23 Dec 2016 23:44:59 +0200, Vassilios Spiliopoulos wrote:> Tim Wescott <seemywebsite@myfooter.really> Wrote in message: >> On Wed, 21 Dec 2016 11:03:57 -0800, yassilis00 wrote: >> >>> On Wednesday, December 21, 2016 at 8:09:20 PM UTC+2, Tim Wescott >>> wrote: >>>> On Wed, 21 Dec 2016 07:36:22 +0200, Vassilios Spiliopoulos wrote: >>>> >>>> > Marcel Mueller <news.5.maazl@spamgourmet.org> Wrote in message: >>>> >> On 20.12.16 23.07, Vassilios Spiliopoulos wrote: >>>> >>> I have an msx 2 machine from 1986. >>>> >>> I bought new Zilog z80 CPUs that are 10x faster than what the >>>> >>> original ones are are I am thinking to replace them. >>>> >>> What will happen? >>>> >> >>>> >> Nothing. >>>> >> It will run at the clock speed of the attached crystal as before. >>>> >> >>>> >>> Some people told me that my computer will become >>>> >>> a complete speed demon. >>>> >>> I would like your opinion >>>> >> >>>> >> They are wrong. >>>> >> >>>> >> Running at significantly higher clock rate would require changes >>>> >> to the circuit and maybe also changes to the software for I/O >>>> >> drivers. >>>> >> >>>> >> >>>> >> Marcel >>>> >> >>>> >> >>>> > So, the circuit will have to be modified in order to install that? >>>> > That computer's integrated OS is Microsoft BASIC. >>>> > So all applications and games for it are on .Bas format and on >>>> > waveform when in cassettes. >>>> > All these software were designed to run on a Zilog z80 @ 2.5mhz. My >>>> > new Zilog z80 is on 20 mhz. >>>> > So I guess that it will load faster? >>>> > What changes it might need? >>>> >>>> So, here's the deal: >>>> >>>> If you just put the chip in and don't change anything else, then >>>> there's a good chance that it'll work the same. Maybe a bit faster >>>> if the new Z80 makes more efficient use of clock cycles, but probably >>>> the same. >>>> >>>> You could boost the clock speed to 20MHz with appropriate changes to >>>> the oscillator circuit, but it's almost certain that your external >>>> memory and peripherals won't be able to keep up, because they're from >>>> the same era and price class as that 2MHz CPU. >>>> >>>> Even if you could just change the clock circuit, then you'd probably >>>> mess up whatever real-time aspects of the computer are there. This >>>> might be limited to the time-of-day clock going through an hour in 8 >>>> minutes, but if the thing generates video it might mean that your >>>> video will be totally screwed up. That computer's from an era where >>>> pauses in execution were timed by software delay loops, and those >>>> would be screwed up as well, so there's a good chance that any games >>>> would be screwed up. >>>> >>>> If you had some significant circuit design and software chops, and >>>> you had access to the original software, then you could make the >>>> change -- but you'd essentially be redesigning the whole computer. >>>> There's a good chance that even if you could get all the right parts >>>> that would fit in all the right holes on the board that you'd run >>>> into board limitations. >>>> >>>> Sorry to be so negative. If you want to try it out, go ahead. >>>> You'll learn something, and that's always worthwhile. >>>> >>>> -- >>>> Tim Wescott Control systems, embedded software and circuit design I'm >>>> looking for work! See my website if you're interested >>>> http://www.wescottdesign.com >>> >>> I see. >>> What I was afraid of was if I risk anything, for example if I risk to >>> destroy the computer...We are talking about rare stuff... >> >> If the chip is soldered in and things work now, I would strongly >> suggest that you leave it alone. Particularly if the board has >> plated-through holes (it almost certainly has two or more layers) then >> it takes considerable expertise to get the chip out without damaging >> the board. >> >> -- >> >> Tim Wescott Wescott Design Services http://www.wescottdesign.com >> >> I'm looking for work -- see my website! >> >> > Yes, the CPU is solderedI wouldn't touch it then. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com I'm looking for work -- see my website!
Reply by ●December 23, 20162016-12-23
On 12/23/2016 4:54 PM, Tim Wescott wrote:> On Fri, 23 Dec 2016 23:44:59 +0200, Vassilios Spiliopoulos wrote: > >> Tim Wescott <seemywebsite@myfooter.really> Wrote in message: >>> On Wed, 21 Dec 2016 11:03:57 -0800, yassilis00 wrote: >>> >>>> On Wednesday, December 21, 2016 at 8:09:20 PM UTC+2, Tim Wescott >>>> wrote: >>>>> On Wed, 21 Dec 2016 07:36:22 +0200, Vassilios Spiliopoulos wrote: >>>>> >>>>>> Marcel Mueller <news.5.maazl@spamgourmet.org> Wrote in message: >>>>>>> On 20.12.16 23.07, Vassilios Spiliopoulos wrote: >>>>>>>> I have an msx 2 machine from 1986. >>>>>>>> I bought new Zilog z80 CPUs that are 10x faster than what the >>>>>>>> original ones are are I am thinking to replace them. >>>>>>>> What will happen? >>>>>>> >>>>>>> Nothing. >>>>>>> It will run at the clock speed of the attached crystal as before. >>>>>>> >>>>>>>> Some people told me that my computer will become >>>>>>>> a complete speed demon. >>>>>>>> I would like your opinion >>>>>>> >>>>>>> They are wrong. >>>>>>> >>>>>>> Running at significantly higher clock rate would require changes >>>>>>> to the circuit and maybe also changes to the software for I/O >>>>>>> drivers. >>>>>>> >>>>>>> >>>>>>> Marcel >>>>>>> >>>>>>> >>>>>> So, the circuit will have to be modified in order to install that? >>>>>> That computer's integrated OS is Microsoft BASIC. >>>>>> So all applications and games for it are on .Bas format and on >>>>>> waveform when in cassettes. >>>>>> All these software were designed to run on a Zilog z80 @ 2.5mhz. My >>>>>> new Zilog z80 is on 20 mhz. >>>>>> So I guess that it will load faster? >>>>>> What changes it might need? >>>>> >>>>> So, here's the deal: >>>>> >>>>> If you just put the chip in and don't change anything else, then >>>>> there's a good chance that it'll work the same. Maybe a bit faster >>>>> if the new Z80 makes more efficient use of clock cycles, but probably >>>>> the same. >>>>> >>>>> You could boost the clock speed to 20MHz with appropriate changes to >>>>> the oscillator circuit, but it's almost certain that your external >>>>> memory and peripherals won't be able to keep up, because they're from >>>>> the same era and price class as that 2MHz CPU. >>>>> >>>>> Even if you could just change the clock circuit, then you'd probably >>>>> mess up whatever real-time aspects of the computer are there. This >>>>> might be limited to the time-of-day clock going through an hour in 8 >>>>> minutes, but if the thing generates video it might mean that your >>>>> video will be totally screwed up. That computer's from an era where >>>>> pauses in execution were timed by software delay loops, and those >>>>> would be screwed up as well, so there's a good chance that any games >>>>> would be screwed up. >>>>> >>>>> If you had some significant circuit design and software chops, and >>>>> you had access to the original software, then you could make the >>>>> change -- but you'd essentially be redesigning the whole computer. >>>>> There's a good chance that even if you could get all the right parts >>>>> that would fit in all the right holes on the board that you'd run >>>>> into board limitations. >>>>> >>>>> Sorry to be so negative. If you want to try it out, go ahead. >>>>> You'll learn something, and that's always worthwhile. >>>>> >>>>> -- >>>>> Tim Wescott Control systems, embedded software and circuit design I'm >>>>> looking for work! See my website if you're interested >>>>> http://www.wescottdesign.com >>>> >>>> I see. >>>> What I was afraid of was if I risk anything, for example if I risk to >>>> destroy the computer...We are talking about rare stuff... >>> >>> If the chip is soldered in and things work now, I would strongly >>> suggest that you leave it alone. Particularly if the board has >>> plated-through holes (it almost certainly has two or more layers) then >>> it takes considerable expertise to get the chip out without damaging >>> the board. >>> >>> -- >>> >>> Tim Wescott Wescott Design Services http://www.wescottdesign.com >>> >>> I'm looking for work -- see my website! >>> >>> >> Yes, the CPU is soldered > > I wouldn't touch it then.If you want a faster computer look for an emulator on the PC. If you want faster hardware, look for the version of your MSX II with an FPGA. If you want a learning challenge, learn to program up your MSX II computer on an FPGA board. -- Rick C
Reply by ●December 25, 20162016-12-25
On 12/21/2016 1:03 PM, yassilis00@gmail.com wrote:> [snip] > I see. > What I was afraid of was if I risk anything, for example if I risk to destroy the computer...We are talking about rare stuff... >Much may depend on the relevant value of "rare stuff". If the relevant metric is "difficulty of restoring to working", the answers given already apply. I the relevant metric is the monetary value of an antique, then any attempted modification likely sets that value to null/zero!
