Path: ...!Xl.tags.giganews.com!local-2.nntp.ord.giganews.com!nntp.supernews.com!news.supernews.com.POSTED!not-for-mail NNTP-Posting-Date: Thu, 25 Apr 2024 05:27:09 +0000 From: boB Newsgroups: sci.electronics.design Subject: Re: Zilog stopping Z80 production Date: Wed, 24 Apr 2024 22:27:08 -0700 Message-ID: References: <8fri2jt9s1o3oef0hcem9l9ql8nku7fdn5@4ax.com> User-Agent: ForteAgent/8.00.32.1272 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 71 X-Trace: sv3-O9ULkcjqIQBtL2+rfZYeB67fATCM1geRl/6Yec0l502MjBJLz1zcdkifcV3cTOFtvbrBZRswheiwAOB!Vaq+P/pMGtWZXQK5wGOBoguOS5aYK634YGuMB2OAS3DCkGTJThXdXAX3FzZjIgCcSlRaDQLZKN+a!kVmptEw= X-Complaints-To: www.supernews.com/docs/abuse.html X-DMCA-Complaints-To: www.supernews.com/docs/dmca.html X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 Bytes: 4197 On Wed, 24 Apr 2024 16:09:33 -0700, Don Y wrote: >On 4/24/2024 1:42 PM, boB wrote: >> On Tue, 23 Apr 2024 18:44:24 -0700, Don Y >> wrote: >> >>> On 4/23/2024 2:40 PM, boB wrote: >>>> I miss playing with my old home built S-100 CP/M computer around 1980. >>>> Those were really the fun days of computing and digital logic >>>> circuits. >>> >>> Nowadays, the Zx80's appeal would be in controlling things. >>> There's little that you can't now do *better* that you would >>> previously have used a CP/M box for. >>> >>>> The other day after hearing the demise of the Z80, I ordered 2 of the >>>> 20 MHz Z80 40 pin devices. I did not even know there was a 20 MHz >>>> version. Not sure what I will ever do with them but who knows ? >>>> Maybe I'll just look at them. >>> >>> Again, in the context of "control" (i.e., deeply embedded), >>> you would likely also need similar speed grade peripherals >>> to do anything. >> >> Yes, I know. Address decoders are a dime a dozen (almost) and any >> other peripherals can either be made or, I may actually have the >> others laying around. I save old ICs and have since the 1970s. > >But those devices won't be of the same (fast) speed grade as the >processor. Remember, all "external (to the CPU) interactions" >happen at a rate defined by the system clock frequency. So, the >RETI daisy chain will have to operate "faster", the devices >will have to put data onto the bus -- and take it off -- quicker, >all rate generators (dividers) will have to be rejiggered for a >faster input clock, any software delay loops (explicit or implied) >will have to be rewired, etc. > The interface isn't that complicated with parts that are available today to build something. OR I could just run the part at 4MHz. >>> I had a particular fondness for the '180 (and '7180!) as it >>> wasn't crippled by the tiny address space (64K memory + 64K I/O) >>> of the Z80. Over the years, I've come to realize that you usually >>> need more space for *code* than data! I am not THAT interested in using an obsolete part. Just wanted one. I may never even use it. boB >> >> Wasn't familiar with those 2. Yes, I would run out of code space with >> many micro controllers. The was always programmed in assembler and >> code was fairly smalll at that time. Amazing we were able to get >> along with less than 64K ! > >The 180 gave you a seamless way to get to 1M of program+data. >(Keep in mind that const data is still data!) > >The 7180 was a microcontroller variant -- 16KB EPROM (OTP) >and 512B of RAM with a smattering of useful I/Os in a >PLCC package. > >There were a couple of other 180 variants that offered >specialized capabilities but I never had a use for those >(*too* sole source; the 180 was eventually second sourced >BY ZILOG :> )