Reply by Vassilis Spiliopoulos●August 20, 20162016-08-20
rickman <gnuarm@gmail.com> Wrote in message:
> On 8/19/2016 5:59 PM, Vassilis Spiliopoulos wrote:
>> rickman <gnuarm@gmail.com> Wrote in message:
>>> On 7/30/2016 5:54 AM, Vassilis Spiliopoulos wrote:
>>>>
>>>> I am going to make a computer or at least attempt to using some
>>>> CPU chips and breadboards. The initial idea is to link each
>>>> output pin such as halt to a led light.And the address buses too
>>>> and link the inputs to switches.It will be a very basic CPU unit.
>>>> What are your thoughts on this?
>>>
>>> This is not really the right group for that question. You might try
>>> comp.arch.embedded for a better response and being on topic with the group.
>>>
>>> --
>>>
>>> Rick C
>>>
>>
>> Hmm. Usually this group is used for hardware related questions and
>> answers
>
> DSP hardware perhaps. Discussing the construction of a simple home
> computer with a Z80 type CPU is not on topic here.
>
> --
>
> Rick C
>
I guess that you are right. Direct me to the proper group then.
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Reply by rickman●August 19, 20162016-08-19
On 8/19/2016 5:59 PM, Vassilis Spiliopoulos wrote:
> rickman <gnuarm@gmail.com> Wrote in message:
>> On 7/30/2016 5:54 AM, Vassilis Spiliopoulos wrote:
>>>
>>> I am going to make a computer or at least attempt to using some
>>> CPU chips and breadboards. The initial idea is to link each
>>> output pin such as halt to a led light.And the address buses too
>>> and link the inputs to switches.It will be a very basic CPU unit.
>>> What are your thoughts on this?
>>
>> This is not really the right group for that question. You might try
>> comp.arch.embedded for a better response and being on topic with the group.
>>
>> --
>>
>> Rick C
>>
>
> Hmm. Usually this group is used for hardware related questions and
> answers
DSP hardware perhaps. Discussing the construction of a simple home
computer with a Z80 type CPU is not on topic here.
--
Rick C
Reply by Vassilis Spiliopoulos●August 19, 20162016-08-19
Vassilis Spiliopoulos <vassilis@vask1lux.de> Wrote in message:
>
> I am going to make a computer or at least attempt to using some
> CPU chips and breadboards. The initial idea is to link each
> output pin such as halt to a led light.And the address buses too
> and link the inputs to switches.It will be a very basic CPU unit.
> What are your thoughts on this?
> --
>
>
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>
Reply by Vassilis Spiliopoulos●August 19, 20162016-08-19
Tom Gardner <spamjunk@blueyonder.co.uk> Wrote in message:
> On 02/08/16 14:48, rickman wrote:
>> On 8/2/2016 9:24 AM, Randy Yates wrote:
>>> herrmannsfeldt@gmail.com writes:
>>>> [...]
>>>> You do need to be able to program EPROMs though, or, I suppose Flash
>>>> memory.
>>>
>>> How I miss the days of the 2732 UVEPROM and my Data I/O programmer (not
>>> to mention 8085 assembly language)! That's when men were men and
>>> programmers were programmers!
>>
>> Not old enough to have used 1702A parts, eh?
>
> Some things are best left in the dim recesses of memory,
> until you want to show kids what a "chip" looks like.
>
>
Doesn't the chip contain integrated memory? It will be a very
basic unit using switches for 0 and 1's
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Reply by Vassilis Spiliopoulos●August 19, 20162016-08-19
Richard Owlett <rowlett@cloud85.net> Wrote in message:
> On 7/30/2016 4:54 AM, Vassilis Spiliopoulos wrote:
>>
>> I am going to make a computer or at least attempt to using some
>> CPU chips and breadboards. The initial idea is to link each
>> output pin such as halt to a led light.And the address buses too
>> and link the inputs to switches.It will be a very basic CPU unit.
>> What are your thoughts on this?
>>
>
> You might get more focused replies by describing your motivation(s).
> Was there a particular Zilog of interest? If so, why? etc.
> HTH
>
>
Zilog Z80
Mainly for its comparative minor cost and compatibility to the CPU
ancestral to the modern ones - the Intel 8080
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Reply by Vassilis Spiliopoulos●August 19, 20162016-08-19
Christian Gollwitzer <auriocus@gmx.de> Wrote in message:
> Am 30.07.16 um 16:16 schrieb Vassilis Spiliopoulos:
>> Christian Gollwitzer <auriocus@gmx.de> Wrote in message:
>>> My very first (actually my father's) computer was one of those:
>>>
>>> https://en.wikipedia.org/wiki/NDR-Klein-Computer
>>>
>> Do you have any information about the schematics? Since your
>> father designed it.
>
> Sorry, that came across in a wrong way. My father did not design that
> computer. It was the first he owned for himself and was accessible to
> me. He bought it as a kit, comprising board, small parts, ICs,
> instruction manual... and then within a few days we soldered it
> together. I learnt to code on that machine, you had to key in Z80
> machine language in hexcode. So I still remember a few opcodes :)
>
> Maybe you can still find the manuals somewhere online. Unfortunately,
> since this was a German TV channel, I suspect that everything is in
> German, unfrotunately. In particular, there is this book:
>
> https://www.amazon.de/Mikrocomputer-selbstgebaut-programmiert-Bauelement-fertigen/dp/3772371620
>
> which decribes very similar computers.
>
> Best regards,
>
> Christian
>
>
Oh brother... That is very unfortunate. My German language skills
are terrible
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Reply by Vassilis Spiliopoulos●August 19, 20162016-08-19
bitrex <bitrex@de.lete.earthlink.net> Wrote in message:
> On 07/30/2016 05:54 AM, Vassilis Spiliopoulos wrote:
>>
>> I am going to make a computer or at least attempt to using some
>> CPU chips and breadboards. The initial idea is to link each
>> output pin such as halt to a led light.And the address buses too
>> and link the inputs to switches.It will be a very basic CPU unit.
>> What are your thoughts on this?
>>
>
> For a one-off, use wire-wrap sockets for the ICs and wire up the
> connections point-to-point under the perfboard.
>
> Those plastic "Radio Shack" plug-in breadboards will give you nothing
> but trouble.
>
Hmm... I don't know what you are talking about. We don't have
Radio Shack stores in my country
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Reply by Vassilis Spiliopoulos●August 19, 20162016-08-19
rickman <gnuarm@gmail.com> Wrote in message:
> On 7/30/2016 5:54 AM, Vassilis Spiliopoulos wrote:
>>
>> I am going to make a computer or at least attempt to using some
>> CPU chips and breadboards. The initial idea is to link each
>> output pin such as halt to a led light.And the address buses too
>> and link the inputs to switches.It will be a very basic CPU unit.
>> What are your thoughts on this?
>
> This is not really the right group for that question. You might try
> comp.arch.embedded for a better response and being on topic with the group.
>
> --
>
> Rick C
>
Hmm. Usually this group is used for hardware related questions and
answers
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Reply by ●August 3, 20162016-08-03
On Tuesday, August 2, 2016 at 10:56:43 PM UTC-7, rickman wrote:
> On 8/2/2016 11:25 AM, Randy Yates wrote:
(snip)
> > I guess not, I don't remember that one! I think prior to the 2732 there
> > were the 2708 and 2716, right? I remember being amazed at how fast
> > memory sizes were increasing.
> I got into electronics design at the time 1702A (256 bytes) were the
> only game in town, but were soon replaced by the 2708, then the 2716 and
> then 2732. I recall I was very impressed with how fast that happened...
> Moore's law in action.
> The 1702A was worse than just small. It required insane high voltage
> pulses on the address and/or data lines which had to be reversed to do
> the programming. I think the other EPROMs were amazingly simple to
> program in comparison.
I never tried to design or build a 1702A or 2708 programmer, but yes,
they are high voltages, but even more, the timing had to be right.
They are fast pulses, overshoot and you might destroy the device.
The 1702A is PMOS, the 2708 NMOS, which affects the polarity.
For the 2716, you supply 25V or 21V, and pulse a TTL level signal.
Much easier.
I built a programmer from a BYTE article, which has a serial port
with UART, a few latches, and a 555 to generate the timing pulse.
Reply by rickman●August 3, 20162016-08-03
On 8/2/2016 11:25 AM, Randy Yates wrote:
> rickman <gnuarm@gmail.com> writes:
>
>> On 8/2/2016 9:24 AM, Randy Yates wrote:
>>> herrmannsfeldt@gmail.com writes:
>>>> [...]
>>>> You do need to be able to program EPROMs though, or, I suppose Flash
>>>> memory.
>>>
>>> How I miss the days of the 2732 UVEPROM and my Data I/O programmer (not
>>> to mention 8085 assembly language)! That's when men were men and
>>> programmers were programmers!
>>
>> Not old enough to have used 1702A parts, eh?
>
> Rick,
>
> I guess not, I don't remember that one! I think prior to the 2732 there
> were the 2708 and 2716, right? I remember being amazed at how fast
> memory sizes were increasing.
I got into electronics design at the time 1702A (256 bytes) were the
only game in town, but were soon replaced by the 2708, then the 2716 and
then 2732. I recall I was very impressed with how fast that happened...
Moore's law in action.
The 1702A was worse than just small. It required insane high voltage
pulses on the address and/or data lines which had to be reversed to do
the programming. I think the other EPROMs were amazingly simple to
program in comparison.
--
Rick C