Re: SD I/O 1.8MHz resonator
Josh: does your serial code do autobaud - i forget? If so it would probably be fine.
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Good morning all,
This is proving to be another hard to find component, so I got a 2MHz one instead. If I understood correctly there's a direct correlation with the terminal baud rate provided by the UART. Would 200KHz make much diference?
Cheers
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Re: SD I/O 1.8MHz resonator
That's like 10% error.? So, 9600 baud becomes 10360 baud.? Should work... only 1 way to find out.
On Friday, April 30, 2021, 05:45:42 a.m. EDT, Zanchius <flavio@...> wrote:
Good morning all,
This is proving to be another hard to find component, so I got a 2MHz one instead. If I understood correctly there's a direct correlation with the terminal baud rate provided by the UART. Would 200KHz make much diference?
Cheers
|
Good morning all,
This is proving to be another hard to find component, so I got a 2MHz one instead. If I understood correctly there's a direct correlation with the terminal baud rate provided by the UART. Would 200KHz make much diference?
Cheers
|
Re: Transistor replacements
Frank Palazzolo wrote: I built my kit to do TTL-serial only, and I don't plan to use real RS-232 voltage levels. Q1 and Q4 (on the Z80MC Front Panel) are only needed for RS-232 serial. So they can be left out. :-) Another alternative would be to find a compatible N-channel and
P-channel FET in a TO-92 package, which would be ok with the maximum
voltages, and then try to orient the part to that footprint. An N-channel MOSFET (like a 2N7000 or BS170) might work for Q2 and Q3. Their base (gate) is pulled either high or low (so never left floating). The base of Q5 is driven by capacitor C5; so you need the base resistors to work. A P-channel MOSFET (BS250) might work if you added a gate-source resistor to insure that it turned it off. Or, you could leave it off -- without it, you can't reset the Z80 with the DTR line from the serial port. For an active part, it seems like you could find a match in a surface mount package, if you're willing to solder that to the top (or bottom, depending on the pinout). Right; there are lots of surface-mount alternatives. But watch the pinouts! Lee Hart -- A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away. -- Antoine de Saint Exupery -- Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com -- This email has been checked for viruses by Avast antivirus software.
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Re: Transistor replacements
Flavio Vinicius Spalato Zanchi wrote: Lee,
Many thanks for the reply. I'm absolutely sure that you and the community created the best design with what was available at the time.
Once again I am out of luck. TME, being in Poland, and thanks to Brexit, doesn't ship to the UK for the time being. So I will take the risk and order the SMD equivalents (MMUN2212LT1G , NSVMMUN2112LT1G),? with a bit of effort I think I can fit them on the board. These pre-biased transistors are handy parts. They save parts, and thus save space on the PCB. They are bipolar, and so are not susceptible to static damage, and don't have parasitic "protection diodes" (which was useful for the RS-232 interface). It's unfortunate that you're in the UK. I have the transistors; but postage for a 1-ounce letter to the UK is over $5, and the minimum package postage is over $15. They also insist that envelopes be "flat". I tried to mail an LED in an envelope, and it arrived with chips knocked out of it! Lee Hart -- A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away. -- Antoine de Saint Exupery -- Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com -- This email has been checked for viruses by Avast antivirus software.
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Re: Transistor replacements
I built my kit to do TTL-serial only, and I don't plan to use real RS-232 voltage levels.? So I have a FJN3303R and a FJN4303R new in the package here.
If you want them, contact me offline at? frank@...?and I will send them to you. ?
For an active part, it seems like you could find a match in a surface mount package, if you're willing to solder that to the top (or bottom, depending on the pinout).
I think a SOT-23 can maybe fit on TO-92 pads?
?
Another alternative would be to find a compatible?N-channel and P-channel FET in a TO-92 package, which would be ok with the maximum voltages, and then try to orient the part to that footprint.
?
?
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Re: Transistor replacements
Flavio,
I built my kit to do TTL-serial only, and I don't plan to use real RS-232 voltage levels.? So I have a FJN3403 and a FJN4303 new in the package here. If you want them, contact me offline at frank@... and I will send them to you.
For an active part, it seems like you could find a match in a surface mount package, if you're willing to solder that to the top (or bottom, depending on the pinout). I think a SOT-23 can fit on TO-92 pads?
Another alternative would be to find a compatible?N-channel and P-channel FET in a TO-92 package, which would be ok with the maximum voltages, and then try to orient the part to that footprint.
On Mon, Apr 26, 2021 at 08:46 AM, Flavio Vinicius Spalato Zanchi wrote:
FJN4303R
yeah, certainly digikey Canada shows out of stock and obsolete.? hopefully lee has an alternate part or source.
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Re: Transistor replacements
Lee,
Many thanks for the reply. I'm absolutely sure that you and the community created the best design with what was available at the time.
Once again I am out of luck. TME, being in Poland, and thanks to Brexit, doesn't ship to the UK for the time being. So I will take the risk and order the SMD equivalents (MMUN2212LT1G , NSVMMUN2112LT1G),? with a bit of effort I think I can fit them on the board.
Flavio
flavio@... wrote:
> I am sourcing the components for the Z80MC, which have brought me to a
> halt trying to find the pre-biased transistors Q1-Q5 used on the front
> panel (FJN3303R, FJN4303R) and even their equivalents (NTE2358,
> NTE2357).? The TO92 versions all seem to be out of production... Are
> there any other equivalents that could be used instead? Glad if anybody
> could point me in the right direction.
These "pre-biased" transistors with internal resistors have been around
for decades, and there are hundreds of part numbers. When I designed
them into the Z80MC, all the major distributors stocked them for a few
cents each.
I buy my PC boards and parts to go on them in batches; so I still have
enough of the FJN3303R and FJN4303R transistors for kits, and to supply
customers who bought the bare boards from me. If that's the case, let me
know. :-)
But the age of through-hole parts is coming to an end. Surface-mount
parts are everywhere; but through-hole versions of the same parts are
disappearing. Digikey and Mouser sold their remaining inventories to
Rochester Electronics. Rochester is a good outfit; but they have a $250
minimum order. For a 3-cent part, that means buying >10,000!
I added the NTE equivalents to my manual. NTE has long been a supplier
of replacement parts for service and repair. They buy a standard part,
add their own part#, and jack up the price. They maintain inventory,
which costs money. So if you only need one, and don't care what it
costs, they've got it!
It doesn't help that manufacturers don't use generic 2Nxxx or 2SBxxx
numbers any more; they hide them with their own "house" numbers, so you
can't easily cross-reference them to other parts. When searching, use
the term "pre-biased transistors" to find them. There are *lots* of
equivalents (especially surface-mount); but they've made them hard to find.
Octopart.com is a free search engine for electronic components. They'll
show who has (or says they have) stock on parts such as these. At the
moment, they list:
NTE2357 NPN $1.20 each
NTE2358 PNP $0.78 each
--
A designer knows he has achieved perfection not when there is
nothing left to add, but when there is nothing left to take away.
? ? ? ? ?-- Antoine de Saint Exupery
--
Lee Hart, 814 8th Ave N, Sartell MN 56377,
--
This email has been checked for viruses by Avast antivirus software.
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Re: Transistor replacements
flavio@... wrote: I am sourcing the components for the Z80MC, which have brought me to a halt trying to find the pre-biased transistors Q1-Q5 used on the front panel (FJN3303R, FJN4303R) and even their equivalents (NTE2358, NTE2357).? The TO92 versions all seem to be out of production... Are there any other equivalents that could be used instead? Glad if anybody could point me in the right direction. These "pre-biased" transistors with internal resistors have been around for decades, and there are hundreds of part numbers. When I designed them into the Z80MC, all the major distributors stocked them for a few cents each. I buy my PC boards and parts to go on them in batches; so I still have enough of the FJN3303R and FJN4303R transistors for kits, and to supply customers who bought the bare boards from me. If that's the case, let me know. :-) But the age of through-hole parts is coming to an end. Surface-mount parts are everywhere; but through-hole versions of the same parts are disappearing. Digikey and Mouser sold their remaining inventories to Rochester Electronics. Rochester is a good outfit; but they have a $250 minimum order. For a 3-cent part, that means buying >10,000! I added the NTE equivalents to my manual. NTE has long been a supplier of replacement parts for service and repair. They buy a standard part, add their own part#, and jack up the price. They maintain inventory, which costs money. So if you only need one, and don't care what it costs, they've got it! It doesn't help that manufacturers don't use generic 2Nxxx or 2SBxxx numbers any more; they hide them with their own "house" numbers, so you can't easily cross-reference them to other parts. When searching, use the term "pre-biased transistors" to find them. There are *lots* of equivalents (especially surface-mount); but they've made them hard to find. Octopart.com is a free search engine for electronic components. They'll show who has (or says they have) stock on parts such as these. At the moment, they list: NTE2357 NPN $1.20 each NTE2358 PNP $0.78 each -- A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away. -- Antoine de Saint Exupery -- Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com -- This email has been checked for viruses by Avast antivirus software.
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Re: Transistor replacements
On Mon, Apr 26, 2021 at 08:46 AM, Flavio Vinicius Spalato Zanchi wrote:
FJN4303R
yeah, certainly digikey Canada shows out of stock and obsolete.? hopefully lee has an alternate part or source.
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Re: Transistor replacements
Hi Josh,
Unfortunately at least in their UK branches they are both not available and marked as obsolete. I've also looked at Farnell with the same result.
gives a list of equivalents but I am not sure which would be better suited.
Curiously enough, Amazon has it but it's a super inflated price, and I would rather pay ?0.50 than ?4.50
Flavio
On Mon, 26 Apr 2021, 14:11 joshbensadon via , <joshbensadon= [email protected]> wrote:
Hi,
I thought Lee included part numbers and sources in the parts list.? I think Digikey probably has these, or Mouser?
Cheers,
Josh
Hi there,
I am sourcing the components for the Z80MC, which have brought me to a halt trying to find the pre-biased transistors Q1-Q5 used on the front panel (FJN3303R, FJN4303R) and even their equivalents (NTE2358, NTE2357).? The TO92 versions all seem to be out of production... Are there any other equivalents that could be used instead? Glad if anybody could point me in the right direction.
Cheers
|
Re: Transistor replacements
Hi,
I thought Lee included part numbers and sources in the parts list.? I think Digikey probably has these, or Mouser?
Cheers,
Josh
On Monday, April 26, 2021, 08:46:21 a.m. EDT, flavio@... <flavio@...> wrote:
Hi there,
I am sourcing the components for the Z80MC, which have brought me to a halt trying to find the pre-biased transistors Q1-Q5 used on the front panel (FJN3303R, FJN4303R) and even their equivalents (NTE2358, NTE2357).? The TO92 versions all seem to be out of production... Are there any other equivalents that could be used instead? Glad if anybody could point me in the right direction.
Cheers
|
Hi there,
I am sourcing the components for the Z80MC, which have brought me to a halt trying to find the pre-biased transistors Q1-Q5 used on the front panel (FJN3303R, FJN4303R) and even their equivalents (NTE2358, NTE2357).? The TO92 versions all seem to be out of production... Are there any other equivalents that could be used instead? Glad if anybody could point me in the right direction.
Cheers
|
Re: Where's the CPM files
I have a multi processor using the SC/MP both the first 8A500 pmos then later 8073.
I have a board I made up with the Nibble basic rom version too.??Their basic issue
was paged the unique 12bit addressing and they were slow compared to 8085 and z80.
When you put cores together on the same silicon you likely have access to the
internal machine and syncing them gets a lot easier.? The yabut is the software
still has to know it has resources and how best to use them to advantage. So
getting multiple cpus to work and share data was easy but Multiplan and Editors
had not one clue?they had additional CPU(s) to work with so no advantage.?
The system software I did take advantage of that but it was far from portable
as it had to know about the resource to use it being CP/M BIOS was the first
place?for devices? to appear.? THe second was doorbell and system control blocks
(SCBs) that were ways to transfer messages, commands, and status.??The
first multitask/multi-user boxes built around MPM and CP/M-3 new of networking
but the number of thing it could do were again not limited by hardware but
applications software so must software at best to print remotely but even then
the software was dumb.
At the time I was also using VAX and PDP-11 systems with multiuser and multitasking?
OSs at their core so as a z80 (z180 and Z280 as well) user it seemed we never got
to a more complete and effective OS with applications in the 8080/8085/z80 realm
of 8bitters.? For the moment Chromix and UZIunix are left out as both had their
own hardware needs and also space limitations to be useful.
Then again when you can have a cpu to yourself neither multitask or multi-user was
high value save for foreground background multitasking as applied to printing
(print spoolers or printer managers).? ?The obvious reason for that is why sit and
wait for printer which had value.
Oddly the 1802 is one of the early cpus where foreground background and simple?
multi task management were both sensible and useful in real time control
applications.
Allison
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Re: Where's the CPM files
Hi Allison:
Thanks for taking the time to explain some of the past design issues and your involvement with them.?
Yea, lots of timing and bottle-neck issues for access to resources. Integrated circuit fabrication was still cutting its teeth back then, so things were slow but getting faster.
I think NATIONAL SEMI was one of the 1st to design a mutli-processor CPU arrangement using their INS8060 and INS8070 series SC/MP CPUs. I was lucky enough to have a friend (who used to work for QXI, a NATIONAL SEMI rep.) sample me an INS8073 with NS tiny BASIC built into RAM. It was literally my very first CPU board design (?.?
In the past decade, I've seen other projects with multiple 8051 cores blazing along at some 400 MHz as well (but not with 12 clock cycles per instr. cycle).
To think what you were doing 40 years ago has ALL been stuffed into single-chip "SoC's" (System on a Chip) with quad ARM cores, many megabytes of RAM and FLASH memory and lots of other peripherals happily running at 1200+ MHz (instead of 6 MHz!). Linux to the rescue for multiprocessing as the OS yielded us the (GOOGLE) "ANDROID" virtual JAVA machine user interface.
For certain, its been an interesting journey, the past few decades. In many ways, I miss the simplistic nature of computing from back then. :)
Peace and blessings,
Scott
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Re: Where's the CPM files
Scott,
Like many of the time performance a was a thing...
Exity was only one and that was later.? IN 1980 I setup to make the meanest
z80 system I could using 6mhz Z80s that were appearing.? Basic design was?
remarkably simple, 4 z80 CPUs each its own board with 64K of ram and a bus
access protocol (S100 BUS) to share data or resources? (disks, Serial IO and
printer).? ?All of the resources were smart as in each had local Z80, 8085, 8749
(printer buffer) to perform tasks.? The goal was to share IO and offload tasks like
find a file or spool to printer.? That meant doing surgery to CP/M to split out parts
so that the master cpu (server) did end up with all the work (Bios stuff or BDOS)
or running a full copy of CP/M on each or the four cpus.? Lots of interprocess
communications, interrupts, plus a little foreground background on each.
Basically the box was a bunch of networked (via parallel bus) cpus and service
providers.
In the end while I ran it for years and proved useful a single faster cpu was
not burdened with as much overhead.? It also proved CP/M based software
while unaware of the multiple cpus was the actual problem as it was unaware
of resources that could be useful.? The hardware was doable and all but software
had to catch up.? Multiprocessing and time slice was the realm of PDP-11 and VAX
or other heavy iron, the Z80 could but the OS was not yet there.
CP/net and MPM made some things easier? but the the existing applications
software was still built for 64K (or smaller) spaces and had no idea of extensions
or how to use them.? That required something Unix or later and all of the seriously
needed larger memory space.
Allison
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Re: Where's the CPM files
Hi Bill,
Yes it all fits together. There is a problem with the FP on top of the SIO though that I haven't tracked down. The FP works fine but there is a segment 'e' I think it is, that is not lit on all characters. I think its a shorted bit on the SIO board, although they all checked out on with an ohm meter when I was testing before plugging it. The CPU and SIO board work fine, as does the FP even when using the bit banging I/O port on the FP with the CPM.
Paul
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Re: Where's the CPM files
If speed is an issue, there is always this route...?
Peace and blessings,
Scott
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Re: Where's the CPM files
Yes, that is the case.? My Kaypro4/84 has a 1mb ramdisk, very fast.
The compupro also has a 512K ram disk and hard disks with smart
controller, faster even at only 4mhz z80.
AT class machines even with then hard disks that the same bottleneck.
The 8080, well, it was just slow, though it beat the tar out of the 8008
by an easy factor of 10x or more.? Still for the first system I ever?
built it was pretty amazing, then I got to see the 8080 instruction set.
Back then the PDP-8 (e or i) was the benchmark used, later PDP-11.
Generally at each moment I was pushing for best performance or
greatest simplicity.? the Z80 or 8085 generally did that well for
most cases.? For less 8049 or 8051.
Allison
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Re: Where's the CPM files
Allison,??
Lee's ALTAID computer uses a 512K RAM chip, 64K for a full memory map and 448K for a single RAM disk. It's fast to access the disk, but the 8080 itself is just chugging along at 2Mhz.
Somethings never change.? I'm guessing in 4 decades from now, it will be the same (if humanity survives). Even back on my XT (or was it on my AT?) I would create RAM Disks and work from them. Today, everyone installs SSD to speed up Windows.
Cheers,
Josh
On Wednesday, September 30, 2020, 10:30:53 a.m. EDT, ajparent1/kb1gmx <kb1gmx@...> wrote:
I've collected and build CP/M systems for decades (over 4)
so I have system that run from sludge slow to current idea of fast.
Z80s at 10mhz, Z180s at 12mhz and A Z280 at 10mhz.
That and no shortage of S100, Multibus, and SBC systems
to run.
Biggest bottleneck is mass storage IO, 5.25 floppy generally
is slow, many hard disks were not fast.? ?Of all CF is usually
fastest (best if 8bit mode) and SD slower as the SD has
more protocol overhead and the serializing if not done in
hardware is slow.? Of course there are implementation
dependencies but the faster?systems usually farm out
the disk/storage IO to a slave cpu in some form.??
Speed is good if it can be had simply.? A Z80 running at? 6, 8
or 10mhz can be simple.?
All that said why speed is nice to have, I use multiplan, Dbase,
smallC, BDS-C, Pascal and a lot of other software like Vedit
and speed helps.
Allison
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Zanchius
Lee Hart
Paul Bigwood