|
I’ve also seen ORANGE CONNEX on a few occasions. I’ve signed up for USPS notifications so that as soon as any package enters their system that targets my mailing address, regardless of origin, I know that a package has “arrived” on US shores … and I can see its subsequent progress. ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of SCOTT VITALE
Sent: Friday, May 28, 2021 3:16 PM
To: [email protected]
Subject: Re: [Z80MC] SD I/O 1.8MHz resonator ? I order parts off of eBay. In many cases, the supplier will ship, as Paul stated, via a "package bundle". Sometimes U.S. vendors do the same thing using DHL or FEDEX. Recently, I've seen the Chinese suppliers using ORANGE CONNEX that usually ends up in Bensonville, U.S. and is then relabeled with a USPS tracking number and sent via USPS. I've seen typically 2 weeks shipping time from China. Sometimes the vendor charges US$2 to US$4 for the shipping and sometimes its free. You can track the package from China to the U.S. via ORANGE CONNEX but afterwards, you don't get the USPS tracking number, so the package can't be tracked once it passes through U.S. customs, which can take 3 - 5 days (slower for caution due to China's attack on U.S. using bio-weapon CV-19). Once shipped via USPS, typically 3 days to arrive to your door.
Peace and blessings,
Scott
|
I order parts off of eBay. In many cases, the supplier will ship, as Paul stated, via a "package bundle". Sometimes U.S. vendors do the same thing using DHL or FEDEX. Recently, I've seen the Chinese suppliers using ORANGE CONNEX that usually ends up in Bensonville, U.S. and is then relabeled with a USPS tracking number and sent via USPS. I've seen typically 2 weeks shipping time from China. Sometimes the vendor charges US$2 to US$4 for the shipping and sometimes its free. You can track the package from China to the U.S. via ORANGE CONNEX but afterwards, you don't get the USPS tracking number, so the package can't be tracked once it passes through U.S. customs, which can take 3 - 5 days (slower for caution due to China's attack on U.S. using bio-weapon CV-19). Once shipped via USPS, typically 3 days to arrive to your door.
Peace and blessings,
Scott
|
Judging by the tracking on my two recent orders it appears that they bundle US (or maybe North American?) orders over some interval into a single package that is shipped to Colorado where it is disaggregated and then individual orders travel via USPS. Interestingly it appears that they "eat" the cost of the drop-ship to Colorado, and the Shipping Cost in the order roughly corresponds to the USPS rate from Colorado based on the package label (which in both cases was marked with a somewhat higher cost than was charged in the order).
I presume that the drop-ship is air mail as it was only a week between order-entry and arrival in Colorado. The second week was spent with USPS Ground.
A very efficient process; I'm impressed. I imagine that they have a similar set-up for other world regions.
I've seen what appears to be similar behavior with Hong Kong (and possibly Chinese) vendors on eBay -- after a pause the package appears to originate at a US location.
Glad to hear that Tayda wasn't foolin' with their availability of the 1.8Mhz resonators :->.
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Lee Hart Sent: Thursday, May 27, 2021 5:36 PM To: [email protected]Subject: Re: [Z80MC] SD I/O 1.8MHz resonator saturn5tony via groups.io wrote: Lee Hart wrote: I did find a source for more 1.8 MHz resonators. I ordered directly
from Tayda Electronics in Thailand, and they arrived. :-)
Oh great Lee. I just did my 1st order with them as well for these 1.8meg
cr's for my new z80 bd. How long did it take to get them? The shipping
was very reasonable. My order took just over 2 weeks to arrive. That's pretty good! I've shipped packages internationally that have taken 4-6 weeks to arrive. Of course, that's "good" compared to last year. Some packages sent in early 2020 took 3-4 months to arrive! Lee -- We cannot solve our problems with the same thinking we used when we created them. -- Albert Einstein -- Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com -- This email has been checked for viruses by Avast antivirus software.
|
saturn5tony via groups.io wrote: Lee Hart wrote: I did find a source for more 1.8 MHz resonators. I ordered directly
from Tayda Electronics in Thailand, and they arrived. :-)
Oh great Lee. I just did my 1st order with them as well for these 1.8meg cr's for my new z80 bd. How long did it take to get them? The shipping was very reasonable. My order took just over 2 weeks to arrive. That's pretty good! I've shipped packages internationally that have taken 4-6 weeks to arrive. Of course, that's "good" compared to last year. Some packages sent in early 2020 took 3-4 months to arrive! Lee -- We cannot solve our problems with the same thinking we used when we created them. -- Albert Einstein -- Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com -- This email has been checked for viruses by Avast antivirus software.
|
On Thu, May 27, 2021 at 11:14 AM, Lee Hart wrote:
I did find a source for more 1.8 MHz resonators. I ordered directly from Tayda Electronics in Thailand, and they arrived. :-)
Oh great Lee. I just did my 1st order with them as well for these 1.8meg cr's for my new z80 bd. How long did it take to get them? The shipping was very reasonable.
|
SCOTT VITALE wrote: FYI: for non-standard baud rates;
I use Linux for all development work and?a USB-2-TTL serial converter for serial I/O. I tested with with CH340 to see how much baud-rate error would be tolerated at 57.6Kb and found up to +7% error was still functional but +10% was no-joy. I also found that anything more than -2% was no-joy.
I use PICOCOM for terminal emulation, which allows one to use ANY baud rate you tell it, so if you are using a 2 MHz oscillator, simply tell PICOCOM your ACTUAL baud rate is 62.5Kb (or whatever) and it'll work. Not sure about WINDOWS terminal emulators. Try it and see. Thanks Scott, The terminal programs I normally use (ProComm and TeraTerm) don't support odd baud rates; I'll have to try the one you suggested. It sounds like a good tool for testing baud rate accuracy. I did find a source for more 1.8 MHz resonators. I ordered directly from Tayda Electronics in Thailand, and they arrived. :-) Best wishes, Lee Hart -- We cannot solve our problems with the same thinking we used when we created them. -- Albert Einstein -- Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com -- This email has been checked for viruses by Avast antivirus software.
|
glad it's working for you.? Did you try other fixed baud rates?
toggle quoted message
Show quoted text
FYI: for non-standard baud rates;
I use Linux for all development work and?a USB-2-TTL serial converter for serial I/O. I tested with with CH340 to see how much baud-rate error would be tolerated at 57.6Kb and found up to +7% error was still functional but +10% was no-joy. I also found that
anything more than -2% was no-joy.
I use PICOCOM for terminal emulation, which allows one to use ANY baud rate you tell it, so if you are using a 2 MHz oscillator, simply tell PICOCOM your ACTUAL baud rate is 62.5Kb (or whatever) and it'll work. Not sure about WINDOWS terminal emulators. Try
it and see.?
Peace and blessings.
|
FYI: for non-standard baud rates;
I use Linux for all development work and?a USB-2-TTL serial converter for serial I/O. I tested with with CH340 to see how much baud-rate error would be tolerated at 57.6Kb and found up to +7% error was still functional but +10% was no-joy. I also found that anything more than -2% was no-joy.
I use PICOCOM for terminal emulation, which allows one to use ANY baud rate you tell it, so if you are using a 2 MHz oscillator, simply tell PICOCOM your ACTUAL baud rate is 62.5Kb (or whatever) and it'll work. Not sure about WINDOWS terminal emulators. Try it and see.?
Peace and blessings.
|
Hi folks!
Just a quick update, it actually works if your terminal client supports custom baud rates. I got my kit fully assembled this morning, and had it working? in no time using GtkTerm under Linux, may work in Putty as well, but I haven't tried yet.
Thanks? for all the help.
|
Thank you Josh, this is very useful.
Flavio
On Sat, 1 May 2021 at 12:07, joshbensadon via <joshbensadon= [email protected]> wrote:
The 8250 has a coarse divider for baud rate.?
12 works to divide 1,843,200 to 9600 baud because
1843200 / 12 / 16 = 9600
The next divider number is 13 and to get 9600 at that value you would need...
X / 13 / 16 = 9600
Solve for X = 1,996,800? ?(so 2Mhz would be pretty decent)
2Mhz gives 9615, = 0.2% error
But, as pointed out, 1.8 is available and 1.8432 crystals will also work (adding the loading caps).
On Friday, April 30, 2021, 04:22:10 p.m. EDT, Lee Hart < leeahart@...> wrote:
Zanchius wrote:
> I would be comfortable in flipping a byte or two on the EPROM image, I
> managed to find a programmer that can burn 27256 chips so that also
> wouldn't be an issue.
> May I ask which bytes should be changed?
Hi Flavio,
Download the EPROM source file at
<> from the website at
<>.
In the .ASM or .LST file, search for "LD (ACE_BAUD),A". It occurs in two
places. The first one sets the initial baud rate to 9600 (with a 1.8 MHz
resonator or 1.8432 crystal). Change the byte at 01AE to whatever is
correct for your crystal and desired baud rate.
01A5? 21 80FF??? COLD_START??? LD??? HL,RC_TYPE
01A8? 06 0F??? ??? ??? LD??? B,CS_CLR_LEN
01AA? CD 100C??? ??? ??? CALL??? CLEAR_BLOCK
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RC_TYPE)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RC_SOFT)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RC_STEP)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RC_CC)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RC_HALT)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RC_F0)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RC_RST0)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RC_HARD)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RegPtr)
? ? ? ? ? ? ? ??? ??? ??? ;DW??? 0??? ;(ABUSS)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(IoPtr)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RX_ERR_LDRT)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RX_ERR_STOP)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RX_ERR_OVR)
01AD? 3E 0C? ??? ??? ??? LD??? A,12 <=== this sets 9600 baud!
01AF? 32 8FFF? ? ? ? ? ??? ??? LD??? (ACE_BAUD),A
Or, if you're using the Z80-CPU card serial port, you can change the
Z80-SIO card baud rate using this call:
080B? CD CA0D? ? ? ? ? PORT_SPEED??? CALL??? PRINTI??? ???
080E? 0D0A2830 433D3936 ??? ??? DB??? CR,LF,"(0C=9600) BAUD:",EOS
0816? 30302920 42415544
081E? 3A00
0820? 3A 8FFF? ? ? ? ? ??? ??? LD??? A,(ACE_BAUD)
0823? CD F60D? ? ? ? ? ??? ??? CALL??? PUT_BYTE
0826? CD 490D? ? ? ? ? ??? ??? CALL??? SPACE_GET_BYTE
0829? D8? ? ? ? ? ? ? ? ??? ??? RET? C
082A? 32 8FFF? ? ? ? ? ??? ??? LD??? (ACE_BAUD),A
082D? CD F214? ? ? ? ? ??? ??? CALL??? ACE_SET_BAUD
0830? C9? ? ? ? ? ? ? ? ??? ??? RET
Hope this helps!
Lee
--
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.
-- Flavio V. S. Zanchi
flavio@...
"Egal, wie dicht du bist, Goethe war Dichter"
-----BEGIN PGP PUBLIC KEY BLOCK----- mQGNBF0sljABDADRxQ8ORa2P6cTMNGi5iJJHCuxaSwinZWz0k6HpWMyd53Vwj7qq
bRHrGTg5nAvFca5HzToYLS992TaYZXrhfDQpYRt4v+3n+HC4v1UjK2/xQobn/K1F
VsqXbcgvu/yXhy/fENXIKKum1a/uXC2gicTZFr3Lr3WWRy5mvBY6Jsx4qI4lc/lO
dFZj7anBWMA++fyCwAqZxeOkBBCxd5mrQzOAlCdmAYAXn4hkIvBh+m3YErKPM/jo
E2ol/4N8Tb9q0OaEwWKSuaiK4GHEuygu+90BttcGMF0KBSnHWXgvN4vlRcRBsMsi
gAFDFgRAB5SDtD4mylI61Xy/sA+eOuCgG+KTj0rNOtNU7VnqrmJZsnmGNEDaAN08
pQtv71XMr1LqqoYCzyYC6ootEgKYDOQf7ThdRvenEbGc47/bHklRC6ae+YcLmrqh
FLOd0qInm5niCTXqErXba+uC2/loSOLMUgwGOCrWLfa5OedcCNKFxfEInJTM559W
KkmjcN3yWo91+FsAEQEAAbQpRmxhdmlvIFYuIFMuIFphbmNoaSA8ZmxhdmlvQHph
bmNoaXVzLm9yZz6JAc4EEwEIADgWIQTwPEwoUKf5mm9e/hBcW95lGMyD5gUCXSyW
MAIbIwULCQgHAgYVCgkICwIEFgIDAQIeAQIXgAAKCRBcW95lGMyD5tieC/9auIC2
2p3q9s8Iakygx1KUJjaY2AG9lb19uXKnQnAsK7b+SzzVZkqmTw55Fiz7hZyzw0dg
/AjpR798u9WNXvQHPOYScD1mGn5nFrjgsUj6uh1dPhwhSNk8CayMH2kPA0nlZzt9
OZus0knVZHqebeCXt+cL8N30c5J0wurWh4Enos5RMUr3AkyUmFgIesmKmtDIS6P2
CA183Lp7Qio3Dl5Z5CBukyR+YlIbCnyRVK0a43zxKJ0nmKxYeVfrr9AjscJcss0h
pCv1qAhHvXOIpOzTFOvo+wr8jX6khayT27s5CuoYBojZ3EkzWp5lfejRZ78F15bo
zbXKCb1acftHyXg5YHg3uXagNmqjvvBvVsJW3ZfhxuEkAfsJKA+8OWak54h5SXCZ
e9VlAxGB/wlYNa7vrVZt3F/tgE7KngoXjUGl6EFRLF+TazaIWwqhOwwoUhASU1hc
Q6ikP9L0oDvEHEHJJ/aW/6qj8+mueYal6AJlr9cuLZPlpYWVI32LqoMpt9C5AY0E
XSyWMAEMAO3PEMY1JZrthB5BqBkvdRvSkBsWKo9xc921+N2FrmyFa+uPMJKYsFbn
BrwI+qj+VfAdq80hTcjlzXyx4A+G2fES1qWxCC6Gt/BfxZHDZGYi1I84tCzsOrcp
j51lA7m06iX7vYCiUdh9u7KZJIgjRH5eAzcA+ZGm1hk2CMgomgrgmyaLimFzZg3U
d/WiDmxxb7BRLAptlvDRIQKPzhj/kut63QieO+j2/1GEBulCdnMWjg6qIfwq0vk2
FPbF+czl6+ToCXpRIGhRLkIm2ddJ5rCzRWJlrtpWKKoDYfE2mDbV8LeeB2k/0CZo
+16q3G+yflZNikcRjTCUU3rhUeqfAdB07F6OmxfDjMoxVRfp5QP6glDbEdbgg7se
njYE1sEsbxo+Bw+7D5VWCJBlWqfbTDAmuP7+QfdkPAyzsDn/QFs0/SvfoIDtT+Rz
jsK7IkPbyW62isRdBmwNEsC5BX5BZ1E1tC96euHRImMHIK4wwJrC+24Lct9RP7VC
gMb/DMxq4QARAQABiQG2BBgBCAAgFiEE8DxMKFCn+ZpvXv4QXFveZRjMg+YFAl0s
ljACGwwACgkQXFveZRjMg+aG/Av+P6WH4H/s5ssCdMd4T+r3a5XD/b1GCYWBQvEl
CwHQOTJU1953AQ5acigQzegqdmP7x4KJpN+RE9Z3DQM4TlIGFAq1Wrq983WbEiH+
r6fPUevYZ0yAs0Jn7Z4+ZVdldfpZ//xYoG5LurVYvQdm8KRboqX+pKvAzvtS+HRS
fNfa17qFA58cQR9G+WeDilTHBGeSElNpvq7ALKVtpgDbhDxkA+YEdYGjkUmhSZMI
sOfW3CMj0EsCtCxw958o0x8L/Pucavd1P/jFPJvTAGHtPK/xLkhBtH39S8dOmMBm
RBHN5cQQBKcd4TuXYpCGYOiKL2YciWhnSMODg5D86GhZse3KSpACn3cCo8a4WNvq
DBW0en+UeTPqQX0pVKO1/k/oPniR7Bv5Heqp3X3FF2vs6qRmiw41xJS5BfZtyUtH
aa1jpDgYiQHFwVXe9Rzzb/DsylkPu6gbH1V/hHkrLqIBU5Gpo43y1BC6vk6Tp6aT
CTnS5Lv4I+SMxR+KMofgFvz8RT4+
=fbH5
-----END PGP PUBLIC KEY BLOCK-----
|
The 8250 has a coarse divider for baud rate.?
12 works to divide 1,843,200 to 9600 baud because
1843200 / 12 / 16 = 9600
The next divider number is 13 and to get 9600 at that value you would need...
X / 13 / 16 = 9600
Solve for X = 1,996,800? ?(so 2Mhz would be pretty decent)
2Mhz gives 9615, = 0.2% error
But, as pointed out, 1.8 is available and 1.8432 crystals will also work (adding the loading caps).
On Friday, April 30, 2021, 04:22:10 p.m. EDT, Lee Hart <leeahart@...> wrote:
Zanchius wrote:
> I would be comfortable in flipping a byte or two on the EPROM image, I
> managed to find a programmer that can burn 27256 chips so that also
> wouldn't be an issue.
> May I ask which bytes should be changed?
Hi Flavio,
Download the EPROM source file at
<> from the website at
<>.
In the .ASM or .LST file, search for "LD (ACE_BAUD),A". It occurs in two
places. The first one sets the initial baud rate to 9600 (with a 1.8 MHz
resonator or 1.8432 crystal). Change the byte at 01AE to whatever is
correct for your crystal and desired baud rate.
01A5? 21 80FF??? COLD_START??? LD??? HL,RC_TYPE
01A8? 06 0F??? ??? ??? LD??? B,CS_CLR_LEN
01AA? CD 100C??? ??? ??? CALL??? CLEAR_BLOCK
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RC_TYPE)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RC_SOFT)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RC_STEP)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RC_CC)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RC_HALT)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RC_F0)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RC_RST0)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RC_HARD)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RegPtr)
? ? ? ? ? ? ? ??? ??? ??? ;DW??? 0??? ;(ABUSS)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(IoPtr)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RX_ERR_LDRT)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RX_ERR_STOP)
? ? ? ? ? ? ? ??? ??? ??? ;DB??? 0??? ;(RX_ERR_OVR)
01AD? 3E 0C? ??? ??? ??? LD??? A,12 <=== this sets 9600 baud!
01AF? 32 8FFF? ? ? ? ? ??? ??? LD??? (ACE_BAUD),A
Or, if you're using the Z80-CPU card serial port, you can change the
Z80-SIO card baud rate using this call:
080B? CD CA0D? ? ? ? ? PORT_SPEED??? CALL??? PRINTI??? ???
080E? 0D0A2830 433D3936 ??? ??? DB??? CR,LF,"(0C=9600) BAUD:",EOS
0816? 30302920 42415544
081E? 3A00
0820? 3A 8FFF? ? ? ? ? ??? ??? LD??? A,(ACE_BAUD)
0823? CD F60D? ? ? ? ? ??? ??? CALL??? PUT_BYTE
0826? CD 490D? ? ? ? ? ??? ??? CALL??? SPACE_GET_BYTE
0829? D8? ? ? ? ? ? ? ? ??? ??? RET? C
082A? 32 8FFF? ? ? ? ? ??? ??? LD??? (ACE_BAUD),A
082D? CD F214? ? ? ? ? ??? ??? CALL??? ACE_SET_BAUD
0830? C9? ? ? ? ? ? ? ? ??? ??? RET
Hope this helps!
Lee
--
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.
|
No, it is very tight on timing so that it can do full duplex bit bang.? But that runs on the 4Mhz Z80.? The 1.8Mhz is for the UART.
On Friday, April 30, 2021, 11:41:09 a.m. EDT, bill rowe <bill_rowe_ottawa@...> wrote:
Josh: does your serial code do autobaud - i forget? If so it would probably be fine.
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
|
You could cheat and just use the original part:?
You'll probably have to wait a few weeks, however :-{.
|
You can order direct from Tayda Electronics, and they *are* stocked (3,988,888 parts claimed).
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Lee Hart Sent: Friday, April 30, 2021 12:04 PM To: [email protected]Subject: Re: [Z80MC] SD I/O 1.8MHz resonator Zanchius 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? Hi Flavio, Yes, I'm having trouble getting the 1.8 MHz resonators as well. Mouser quit carrying them, so I bought my last batch from Tayda2009 on ebay. But they seem to have gone out of business. As for the FJN3303 and FJN4303 transistors, I have enough for customers; but shipping to the UK is expensive. The frequency is critical to get the right baud rate. Changing from 1.8 to 2.0 MHz will change the baud rate from 9600 to 1066 baud. It will still work if you can set your Terminal program for such an oddball rate. A better solution is to get a 1.8432 MHz crystal, which is a standard frequency and fairly easy to find. Crystals don't have the internal capacitors, so you'll also need to add two 20pf capacitors, one from each side of the crystal to GND (the schematic in the manual shows these capacitors). Another option is to change the divisor in the 8250 UART. This can compensate for your 2 MHz resonator. But it means changing a byte in the EPROM, and burning another one. Lee -- 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.
|
Lee,
That's brilliant! Thank you for the information.
And thank you everyone for your help as well.
Now the wait for the boards to arrive...
(+_+)
Flavio
Zanchius wrote:
> Humm ... This adds another gremlin in the equation. I'm starting to
> regret ordering only the PCBs.
>
> But hey, there isn't any fun without problems to solve. I may have a
> handful of 1.8432MHz crystal oscillators in my stock so I'll give it a try.
That will work. 1.8432 MHz hits 9600 baud exactly. The 1.80 MHz
resonator is actually 2.4% low (but it works anyway).
Lee
--
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.
|
Zanchius wrote: Humm ... This adds another gremlin in the equation. I'm starting to regret ordering only the PCBs.
But hey, there isn't any fun without problems to solve. I may have a handful of 1.8432MHz crystal oscillators in my stock so I'll give it a try. That will work. 1.8432 MHz hits 9600 baud exactly. The 1.80 MHz resonator is actually 2.4% low (but it works anyway). Lee -- 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.
|
Zanchius wrote: I would be comfortable in flipping a byte or two on the EPROM image, I managed to find a programmer that can burn 27256 chips so that also wouldn't be an issue.
May I ask which bytes should be changed? Hi Flavio, Download the EPROM source file at <> from the website at <>. In the .ASM or .LST file, search for "LD (ACE_BAUD),A". It occurs in two places. The first one sets the initial baud rate to 9600 (with a 1.8 MHz resonator or 1.8432 crystal). Change the byte at 01AE to whatever is correct for your crystal and desired baud rate. 01A5 21 80FF COLD_START LD HL,RC_TYPE 01A8 06 0F LD B,CS_CLR_LEN 01AA CD 100C CALL CLEAR_BLOCK ;DB 0 ;(RC_TYPE) ;DB 0 ;(RC_SOFT) ;DB 0 ;(RC_STEP) ;DB 0 ;(RC_CC) ;DB 0 ;(RC_HALT) ;DB 0 ;(RC_F0) ;DB 0 ;(RC_RST0) ;DB 0 ;(RC_HARD) ;DB 0 ;(RegPtr) ;DW 0 ;(ABUSS) ;DB 0 ;(IoPtr) ;DB 0 ;(RX_ERR_LDRT) ;DB 0 ;(RX_ERR_STOP) ;DB 0 ;(RX_ERR_OVR) 01AD 3E 0C LD A,12 <=== this sets 9600 baud! 01AF 32 8FFF LD (ACE_BAUD),A Or, if you're using the Z80-CPU card serial port, you can change the Z80-SIO card baud rate using this call: 080B CD CA0D PORT_SPEED CALL PRINTI 080E 0D0A2830 433D3936 DB CR,LF,"(0C=9600) BAUD:",EOS 0816 30302920 42415544 081E 3A00 0820 3A 8FFF LD A,(ACE_BAUD) 0823 CD F60D CALL PUT_BYTE 0826 CD 490D CALL SPACE_GET_BYTE 0829 D8 RET C 082A 32 8FFF LD (ACE_BAUD),A 082D CD F214 CALL ACE_SET_BAUD 0830 C9 RET Hope this helps! Lee -- 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.
|
bill rowe wrote: Josh: does your serial code do autobaud - i forget? If so it would probably be fine. No; it doesn't autobaud. But there are two serial ports; one on the Z80-CPU board, and another on the Z80-SIO board. The one on the CPU board uses the 4 MHz resonator; so it will still work. It is fixed at 9600 baud; but would be 4800 baud if you used a 2 MHz resonator, or 19200 if you used 8 MHz etc. The 8250 UART on the Z80-SIO board uses the 1.8 MHz resonator. 18.432 MHz and 3.072 MHz happen to give you all the standard baud rates from 50-38.4Kbaud with negligible error. See the 8250/82C50/16C450 datasheet for details on how to calculate the baud rate constant for various frequencies. Lee -- 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.
|
Humm ... This adds another gremlin in the equation. I'm starting to regret ordering only the PCBs.
But hey, there isn't any fun without problems to solve. I may have a handful of 1.8432MHz crystal oscillators in my stock so I'll give it a try.
F?
On Fri, 30 Apr 2021, 18:39 Mark Moulding, < mark@...> wrote: A 10% error is really too big, for serial communications.? It miiiight still work, but I strongly doubt it, because by the time you get to the end of the character (10 bits in - start, 8-data, stop), you're a full bit time off.? Most UARTS use an internal clock that's a multiple of the baud rate - typically 16 times - and do their sample for each bit on what should be the middle of the bit (for example, 8 clocks after the one that detected the start bit).? This means that by the end of the character, it's sampling the wrong bit in the serial stream.
I found that errors of less than 3% usually work; I try to keep the timing error to half that or better if at all possible.? Lee's recommendation of a 1.8432 crystal comes in with an error of about 2.4%, which should work fine.
~~
Mark Moulding
|
A 10% error is really too big, for serial communications.? It miiiight still work, but I strongly doubt it, because by the time you get to the end of the character (10 bits in - start, 8-data, stop), you're a full bit time off.? Most UARTS use an internal clock that's a multiple of the baud rate - typically 16 times - and do their sample for each bit on what should be the middle of the bit (for example, 8 clocks after the one that detected the start bit).? This means that by the end of the character, it's sampling the wrong bit in the serial stream.
I found that errors of less than 3% usually work; I try to keep the timing error to half that or better if at all possible.? Lee's recommendation of a 1.8432 crystal comes in with an error of about 2.4%, which should work fine.
~~
Mark Moulding
|
Lee Hart
Zanchius