Re: CMOS for NMOS
On 04/16/2018 07:23 AM, Holm Tiffe wrote: > allison via cctalk wrote: > >> On 04/15/2018 10:25 AM, David Griffith via cctalk wrote: >>> I'm pondering upgrading the CPU of a Pacccomm Tiny-2 Mk2 radio packet >>> controller from a 6Mhz Z80 processor and SIO to 10Mhz parts. My >>> problem is that the parts already in it appear to be NMOS. The family >>> is still being made by Zilog, but for 10Mhz parts, CMOS is all they >>> have. Can I just drop in CMOS, change out the crystal/oscillator and >>> have things work as expected? >>> >> No, and why? >> >> Changing to CMOS can cut power drain. However speeding up clocks can >> make the packet controller >> broken even if it runs! If you keep the 6mhz clock all will be fine. >> >> You do not want to alter the output data rate to the modem side. Also >> the other devices on the bus have >> to be able to run at 10mhz. >> >> I have in the past upgraded my AmproLB+ to CMOS but that was to lower >> power needs for >> battery operation. However there was no intent to go faster. >> >> >> Allison >> >> >>> Here's what are fitted to my TNC. >>> >>> Z84C00BB6 >>> Z80BCPU >>> 29125 >>> >>> Z8440BB1 >>> Z80BSIO-O >>> 29014 >>> > Power drain? ..just not interresting here. Electrically there is no problem > changing an Z80 NMOS Part against an CMOS Version, but you are right in > sight of the speeds of the serial connections. > > Z84C00 ..is an CMOS Variant of the CPU, Z8440 is the NMOS Version of the > SIO ..but.. > The Z80 Processor needs external memory Parts, RAM and EPROM mostly, > I don't think that the manufacurer of the TNC has fitted faster Parts as > neccessary since they are much more expensive. > Given that, you would not only get an unit that works with wrong speeds > over serial lines, I would expect an just "not working" unit... As a radio amateur and engineer in the communications realm, and embedded systems designer I know the CMOS Z80 family well. I even have a tube of the 84C0010 (CMOS 10mhz Z80 with 1k ram and Clock Controller) which of all the 40 pin z80s is likely the ultimate part. I designed with it a a long time ago and was an early adopter. Changing up to CMOS z80 makes sense if... you wish to reduce power, or you want to go faster, or you need a bit more operating temperature headroom. For logic levels its fully compatible save for you may not use all the capability. However in most TNCs and unless the modem side (for the RF interface)) is separately crystal controlled going faster will very likely break the unit. Why? Ram/ROM must keep up and all the peripherals have to as well. An oddity of Z80 systems is that while fast Z80s were common enough the peripherals often needed added wait states for interrupt propagation and some did not have the needed speed on the bus requiring added wait states for IO. Then we have the non z80 peripherals like the modem that may require care. The above is why the CMOS z80 with integrated clock controller was really important. Now packet modems I remember worked well even with the 2.5mhz part. Speed of the processor was rarely an issue as the RF side of the modem was generally slow as in 9600 baud max (VHF/uhf) and restricted to 1200 baud on many bands. I helped build a digipeter (packet store and forward repeater) once and in that case CMOS was desired to allow battery backup with long up times. A 4mhz cmos z80 (and everything else cmos) did the job well. Allison > Regards, > > Holm
Re: CMOS for NMOS
allison via cctalk wrote: > On 04/15/2018 10:25 AM, David Griffith via cctalk wrote: > > > > I'm pondering upgrading the CPU of a Pacccomm Tiny-2 Mk2 radio packet > > controller from a 6Mhz Z80 processor and SIO to 10Mhz parts. My > > problem is that the parts already in it appear to be NMOS. The family > > is still being made by Zilog, but for 10Mhz parts, CMOS is all they > > have. Can I just drop in CMOS, change out the crystal/oscillator and > > have things work as expected? > > > No, and why? > > Changing to CMOS can cut power drain. However speeding up clocks can > make the packet controller > broken even if it runs! If you keep the 6mhz clock all will be fine. > > You do not want to alter the output data rate to the modem side. Also > the other devices on the bus have > to be able to run at 10mhz. > > I have in the past upgraded my AmproLB+ to CMOS but that was to lower > power needs for > battery operation. However there was no intent to go faster. > > > Allison > > > > Here's what are fitted to my TNC. > > > > Z84C00BB6 > > Z80BCPU > > 29125 > > > > Z8440BB1 > > Z80BSIO-O > > 29014 > > Power drain? ..just not interresting here. Electrically there is no problem changing an Z80 NMOS Part against an CMOS Version, but you are right in sight of the speeds of the serial connections. Z84C00 ..is an CMOS Variant of the CPU, Z8440 is the NMOS Version of the SIO ..but.. The Z80 Processor needs external memory Parts, RAM and EPROM mostly, I don't think that the manufacurer of the TNC has fitted faster Parts as neccessary since they are much more expensive. Given that, you would not only get an unit that works with wrong speeds over serial lines, I would expect an just "not working" unit... Regards, Holm -- Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe, Freiberger Straße 42, 09600 Oberschöna, USt-Id: DE253710583 i...@tsht.de Fax +49 3731 74200 Tel +49 3731 74222 Mobil: 0172 8790 741
Re: CMOS for NMOS
On 04/15/2018 05:08 PM, allison via cctalk wrote: > On 04/15/2018 10:25 AM, David Griffith via cctalk wrote: >> >> I'm pondering upgrading the CPU of a Pacccomm Tiny-2 Mk2 radio packet >> controller from a 6Mhz Z80 processor and SIO to 10Mhz parts. My >> problem is that the parts already in it appear to be NMOS. The family >> is still being made by Zilog, but for 10Mhz parts, CMOS is all they >> have. Can I just drop in CMOS, change out the crystal/oscillator and >> have things work as expected? >> > No, and why? > > Changing to CMOS can cut power drain. However speeding up clocks can > make the packet controller > broken even if it runs! If you keep the 6mhz clock all will be fine. Quite correct, Allison. I confined my answer to "Can I drop a CMOS Z80 into an NMOS Z80 socket?" And in particular, why not run the 10MHz part at the original 4MHz or whatever? A 10MHz part doesn't mean that it has to run at 10MHz. As to the rest of the question, I confess that I was blind. --Chuck
Re: CMOS for NMOS
On 04/15/2018 10:25 AM, David Griffith via cctalk wrote: > > I'm pondering upgrading the CPU of a Pacccomm Tiny-2 Mk2 radio packet > controller from a 6Mhz Z80 processor and SIO to 10Mhz parts. My > problem is that the parts already in it appear to be NMOS. The family > is still being made by Zilog, but for 10Mhz parts, CMOS is all they > have. Can I just drop in CMOS, change out the crystal/oscillator and > have things work as expected? > No, and why? Changing to CMOS can cut power drain. However speeding up clocks can make the packet controller broken even if it runs! If you keep the 6mhz clock all will be fine. You do not want to alter the output data rate to the modem side. Also the other devices on the bus have to be able to run at 10mhz. I have in the past upgraded my AmproLB+ to CMOS but that was to lower power needs for battery operation. However there was no intent to go faster. Allison > Here's what are fitted to my TNC. > > Z84C00BB6 > Z80BCPU > 29125 > > Z8440BB1 > Z80BSIO-O > 29014 >
Re: CMOS for NMOS
On 04/15/2018 07:25 AM, David Griffith via cctalk wrote: > > I'm pondering upgrading the CPU of a Pacccomm Tiny-2 Mk2 radio packet > controller from a 6Mhz Z80 processor and SIO to 10Mhz parts. My problem > is that the parts already in it appear to be NMOS. The family is still > being made by Zilog, but for 10Mhz parts, CMOS is all they have. Can I > just drop in CMOS, change out the crystal/oscillator and have things > work as expected? The I/O on the NMOS Z80A chips is TTL-compatible. You should have little problem dropping in the CMOS version. The same applies for similar chips, such as the 80C85/8085, 80C86/8086, etc. --Chuck
CMOS for NMOS
I'm pondering upgrading the CPU of a Pacccomm Tiny-2 Mk2 radio packet controller from a 6Mhz Z80 processor and SIO to 10Mhz parts. My problem is that the parts already in it appear to be NMOS. The family is still being made by Zilog, but for 10Mhz parts, CMOS is all they have. Can I just drop in CMOS, change out the crystal/oscillator and have things work as expected? Here's what are fitted to my TNC. Z84C00BB6 Z80BCPU 29125 Z8440BB1 Z80BSIO-O 29014 -- David Griffith d...@661.org A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?
