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ECB VDU [message #2395] Sat, 15 April 2017 00:48 Go to next message
Jonas is currently offline  Jonas
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More than a few years ago I bought a lot of mc6845 (R6845, UM6845, SY6845 et cetera) ICs. I wanted to build a replica of the K&P 80-column interface board for my Sharp MZ-700. The board is one of many yet-to-be-done projects. Maybe sometime in a less hectic future.

I also want to build the ECB VDU board. I cannot find any manufacturing files in archive, though, just PDFs with the schematic, board layouts and a lot of info. I really appreciate some help!

Jonas

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Re: ECB VDU [message #2396 is a reply to message #2395] Sat, 15 April 2017 03:18 Go to previous messageGo to next message
lynchaj is currently offline  lynchaj
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https://retrobrewcomputers.org/n8vem-pbwiki-archive/0/358453 34/48860720/4200893/index.htm
  • Attachment: ECB VDU.zip
    (Size: 1.97MB, Downloaded 460 times)

[Updated on: Sat, 15 April 2017 03:34]

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Re: ECB VDU [message #2398 is a reply to message #2396] Sat, 15 April 2017 03:37 Go to previous messageGo to next message
lynchaj is currently offline  lynchaj
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If there are other old board projects that people want just let me know as I have backups which go way back to the beginning

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Re: ECB VDU [message #2400 is a reply to message #2396] Sat, 15 April 2017 06:44 Go to previous messageGo to next message
Jonas is currently offline  Jonas
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Thank you Andrew! Smile

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Re: ECB VDU [message #2402 is a reply to message #2400] Sat, 15 April 2017 08:04 Go to previous messageGo to next message
lynchaj is currently offline  lynchaj
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There are a bunch of interesting but dead projects that started for one reason or another and died before seeing the light of day. Some a real heart-breakers like the S-100 MSX board, S-100 uPD7220 GDC, various ECB boards. Some ideas just never take off for whatever reason.

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Re: ECB VDU [message #2407 is a reply to message #2402] Sat, 15 April 2017 09:13 Go to previous messageGo to next message
jcoffman is currently offline  jcoffman
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lynchaj wrote on Sat, 15 April 2017 08:04
There are a bunch of interesting but dead projects that started for one reason or another and died before seeing the light of day. Some a real heart-breakers like the S-100 MSX board, S-100 uPD7220 GDC, various ECB boards. Some ideas just never take off for whatever reason.


Curious that a discussion of Video cards should come up at this time. The 6845-based VDU was, I believe, the first. The uPD7220 GDC was a double board, but the 7220 was a difficult chip to tangle with. It was graphics only. The Color VDU, based on the MOS 8563R9 chip for video and the VIA 82C42 for keyboard (PS/2) was a nearly complete solution, but failed because the output was at EGA frequencies. The 8563 was just not fast enough for VGA, and EGA monitors (or multisync) monitors are just no longer readily available. The Propeller I/O did VGA video, keyboard, SD interface; but the chip could not generate interrupts, a limitation which precluded its use with several of the interrupt driven ECB CPU systems.

I have discovered a CRTC which is fast enough for VGA, the HD6445CP4, and am trying to combine it with the VIA 82C42 to make a complete PS/2-VGA solution. Prototype boards are on order, but any results, positive or negative, are weeks away.

Another solution would be one of the VGA solutions on a chip. However, I am very shy of these "millipedes," as I call them.

--John

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Re: ECB VDU [message #2408 is a reply to message #2407] Sat, 15 April 2017 09:18 Go to previous messageGo to next message
Andrew B is currently offline  Andrew B
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Thanks for the ECB VDU files Andrew L.

I really need to get back to updating the new wiki pages for the ECB boards.

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Re: ECB VDU [message #2424 is a reply to message #2407] Sun, 16 April 2017 05:01 Go to previous messageGo to next message
Jonas is currently offline  Jonas
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jcoffman wrote on Sat, 15 April 2017 09:13

I have discovered a CRTC which is fast enough for VGA, the HD6445CP4, and am trying to combine it with the VIA 82C42 to make a complete PS/2-VGA solution. Prototype boards are on order, but any results, positive or negative, are weeks away.

Another solution would be one of the VGA solutions on a chip. However, I am very shy of these "millipedes," as I call them.

--John


Wow! I guess we will see positive results John!

I have actually built two of Sergey´s TVGA9000i VGA boards with success. 160-pin, PFP package, with pins spaced on 0.025" centers. "Millipedes" I guess! I hand-soldered them without issues, thanks to thousands of hours training with the soldering iron, +3.5 reading glasses, good light and a steady hand. I do prefer through-hole components with nice pins spaced on 0.1" centers. "Millipedes" are not hobbyist friendly!

Jonas

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Re: ECB VDU [message #2453 is a reply to message #2407] Tue, 18 April 2017 12:43 Go to previous messageGo to next message
danwerner is currently offline  danwerner
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Hey John,

I do not have a bunch of time (really only a few hours/week these days), but I am very interested in a workable VGA system and would be willing to help out with the new card if you like. (at least as much as I can) I had been focusing on the ColorVDU/SBC-188 but if there is a replacement in the works . . . . .

Feel free to reach out via e-mail if you are interested in assistance-- danwerner21 at gmail.

Dan

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Re: ECB VDU [message #2460 is a reply to message #2395] Tue, 18 April 2017 15:23 Go to previous messageGo to next message
Wayne W is currently offline  Wayne W
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Very excited to hear about this new VDU board John. I realize it is still at the experimental stage, but hope it works out. A capable VGA compatible VDU board is sorely needed for the ECB family of CPUs.

-Wayne

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Re: ECB VDU [message #2929 is a reply to message #2460] Mon, 29 May 2017 19:53 Go to previous messageGo to next message
jcoffman is currently offline  jcoffman
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The successor to the Color VDU, the "VGA3" as it has been called in development, is working on the ECB bus on all of the systems I can check it on: SBCv2, Z180 MarkIV, SBC-188, Mini-M68k, and KISS-68030. With the Zilog CPUs it uses register addressing of video memory. With the CPUs that can address memory directly on the ECB bus, video memory is directly mapped. Detailed information is on the Wiki.

The first production run is due mid- to late-June. This is a 4-layer board; all through-hole components; no SMD, no millipedes. Smile

--John

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Re: ECB VDU [message #2930 is a reply to message #2929] Mon, 29 May 2017 21:09 Go to previous messageGo to next message
Andrew B is currently offline  Andrew B
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John, you have no idea how happy that makes me Smile

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Re: ECB VDU [message #2932 is a reply to message #2929] Tue, 30 May 2017 03:42 Go to previous messageGo to next message
Jonas is currently offline  Jonas
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jcoffman wrote on Mon, 29 May 2017 19:53
The successor to the Color VDU, the "VGA3" as it has been called in development, is working on the ECB bus on all of the systems I can check it on: SBCv2, Z180 MarkIV, SBC-188, Mini-M68k, and KISS-68030. With the Zilog CPUs it uses register addressing of video memory. With the CPUs that can address memory directly on the ECB bus, video memory is directly mapped. Detailed information is on the Wiki.

The first production run is due mid- to late-June. This is a 4-layer board; all through-hole components; no SMD, no millipedes. Smile

--John


Yes!!! Smile

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Re: ECB VDU [message #2938 is a reply to message #2929] Tue, 30 May 2017 15:11 Go to previous messageGo to next message
adx is currently offline  adx
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It's great to hear the VGA board was a success. It's one I'll definitely be building.

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Re: ECB VDU [message #3105 is a reply to message #2938] Thu, 22 June 2017 13:52 Go to previous messageGo to next message
jcoffman is currently offline  jcoffman
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The ECB VGA3 boards have arrived. Last evening I posted the alpha BIOS codes for SBC-188. The board information is under ECB:boards, and the BIOS is under 'FirmwareOS:SBC188'.

Be aware, the BIOS is not yet complete, but video terminal (serial) output works fine. Scrolling is a lot faster and cleaner than the Color VDU.

It's kinda nice to run a computer that does not have to be tied to another computer (or serial terminal). Ahhh ..., back to the days of the original PC.

--John

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Re: ECB VDU [message #6010 is a reply to message #2408] Sat, 23 February 2019 22:34 Go to previous messageGo to next message
b1ackmai1er is currently offline  b1ackmai1er
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Completed my ECB-VDU board Smile

I have done some updates to the wiki.

Couple of spare board listed on inventory page if anyone is interested.

/forum/index.php?t=getfile&id=1270&private=0

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Re: ECB VDU [message #6081 is a reply to message #6010] Sun, 10 March 2019 07:09 Go to previous messageGo to next message
b1ackmai1er is currently offline  b1ackmai1er
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Todays fun: 256 Character modification for ECB-VDU

https://www.retrobrewcomputers.org/doku.php?id=boards:ecb:vd u:fonts#character_set_modification

/forum/index.php?t=getfile&id=1282&private=0

/forum/index.php?t=getfile&id=1281&private=0

/forum/index.php?t=getfile&id=1283&private=0
  • Attachment: 256cdemo.jpg
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  • Attachment: 12x8gfx1.png
    (Size: 6.26KB, Downloaded 1255 times)
  • Attachment: 256cmod1.png
    (Size: 155.55KB, Downloaded 1173 times)

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Re: ECB VDU [message #6222 is a reply to message #6081] Fri, 05 April 2019 04:54 Go to previous messageGo to next message
b1ackmai1er is currently offline  b1ackmai1er
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Hi Guys,

Still playing with this fun little board. I feel there is something not quite right.
If I boot to serial console at 38400 and load the monitor and dump 64k memory i.e. D 0000 FFFF it takes 1m18s to complete.

If I boot to vdu console and do the same it take 1m38s to display the same 64K of memory.

I would expect it to be the same if not faster.

Any ideas why this is?

Regards Phil

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Re: ECB VDU [message #6224 is a reply to message #6222] Fri, 05 April 2019 08:47 Go to previous messageGo to next message
jcoffman is currently offline  jcoffman
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Phil,

1. boot to SIO; load monitor; dump CRTmem to SIO or CRT?
2. boot to CRT; dump CRTmem to CRT; correct?

Question is on 1.

#2. May incur OS (CP/M) console overhead.

--John

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Re: ECB VDU [message #6225 is a reply to message #6224] Fri, 05 April 2019 20:57 Go to previous messageGo to next message
Wayne W is currently offline  Wayne W
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I am not at all surprised that the VDU is a little slower than a pure 38,400 baud line speed.

First, there is a lot of code involved in getting characters to the screen. Even though you are using the debug monitor, you still have the overhead of the entire VT100 emulation code of RomWBW HBIOS involved. Scrolling is especially painful. Although the VDU can scroll simply by adjusting the offset register, you still need to fill the entire new line being exposed.

Second, every read/write of a byte from/to the CRT controller chip must wait for the chip to indicate it is ready. I believe this is because the chip is multiplexing access to the video RAM buffer.

Finally, the cursor position is updated every time a character is output. Updating the cursor position requires two more register writes each time it is updated.

In the end, I think the VDU is actually doing pretty well if it is nearly as fast as pure 38400 baud output.

-Wayne

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Re: ECB VDU [message #6226 is a reply to message #6225] Sat, 06 April 2019 18:05 Go to previous messageGo to next message
b1ackmai1er is currently offline  b1ackmai1er
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Hi Wayne, thanks for the confirmation.

I guess I have become spoilt by computers running in the GHz range!

With the VDU code there does not seem to be any specific wrap-around handling for character being written to video ram. The VDU is designed with 32Kb RAM but from what I can see 2Kb RAM would work just as well if the top unused address lines were tied high or low. Does that sound right?

Regards Phil.

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Re: ECB VDU [message #6227 is a reply to message #6226] Sun, 07 April 2019 06:56 Go to previous messageGo to next message
jcoffman is currently offline  jcoffman
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RE: 32K vs 2K

As with the IBM MDA/EGA/VGA & BIOS's, multiple screen images may be maintained. This was especially useful back in the days of the MSC Codeview debugger. Linux still supports multiple console screens in command mode.

--John

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Re: ECB VDU [message #7137 is a reply to message #2395] Wed, 26 February 2020 14:19 Go to previous messageGo to next message
b1ackmai1er is currently offline  b1ackmai1er
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Good morning,

I have been playing around with my VDU card but cannot work out how to read a byte from the VDU memory.

Anyone got any ideas?

Thanks.

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Re: ECB VDU [message #7138 is a reply to message #7137] Wed, 26 February 2020 15:13 Go to previous messageGo to next message
Wayne W is currently offline  Wayne W
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b1ackmai1er wrote on Wed, 26 February 2020 14:19
I have been playing around with my VDU card but cannot work out how to read a byte from the VDU memory.

There is an example in RomWBW. The vdu.asm driver has a routine called VDU_BLKCPY that starts by reading a block of data from the VDU RAM.

Essentially, you set the VDU RAM offset address in VDU registers 18 & 19 (16 bit address), then set the VDU register to 31 and read bytes from the VDU RAM READ port.

-Wayne

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Re: ECB VDU [message #7140 is a reply to message #7138] Thu, 27 February 2020 02:49 Go to previous messageGo to next message
b1ackmai1er is currently offline  b1ackmai1er
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Thanks Wayne, I was trying to work it out from the schematic but was totally confused.

Regards Phil.

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Re: ECB VDU [message #7205 is a reply to message #7140] Sun, 08 March 2020 08:17 Go to previous messageGo to next message
b1ackmai1er is currently offline  b1ackmai1er
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Had some success with reimplementing NASCOM BASIC graphics primitives for the ECB-VDU

10 REM Border
20 FOR X=0 TO 159
30 SET (X,0)
40 SET (X,72)
50 SET (0,INT(X/2)) : SET (159,INT(X/2))
60 NEXT X
65 REM Sine
70 FOR A=0 TO 359
72 X=INT((A/359)*159)
75 Y=INT(SIN(A*0.0175)*35)-1
80 SET (X,Y+37)
90 NEXT A

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Re: ECB VDU [message #7209 is a reply to message #2395] Sun, 08 March 2020 22:34 Go to previous messageGo to next message
bifo is currently offline  bifo
Messages: 48
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Question about this board: Are the PS2 and Keyboard ports tied in specifically with the CTRC? I'm thinking about building one as an 80 column upgrade for my N8, but I was wondering how the PS2 ports on the N8 would interact with the ports on the VDU board. Is it all done in the ROMWBW software, and would there be potential clashes with having 3 PS2 ports and 2 differently implemented keyboard ports? Would it be possible to just build the VDU portion and not implement the keyboard and mouse ports without breaking functionality?

I'm pretty sure this isn't a use case anyone foresaw so if nobody knows that's fine.

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Re: ECB VDU [message #7210 is a reply to message #7209] Mon, 09 March 2020 02:56 Go to previous messageGo to next message
b1ackmai1er is currently offline  b1ackmai1er
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Hi,
The 8255 PPI controlling the keyboard and mouse port is not directly tied to the 6545 CRCT VDU controller.
There should be no port conflict between the two.
Yes you could omit the keyboard and mouse hardware without affecting the video hardware section.
On the software side, both video devices use the same keyboard driver and I don't think it supports multiple instances.
So I think the keyboard would only work on one device.
However with console redirection (FORCECON) you should be able to redirect all I/O to the VDU
Maybe even CP/M iobyte redirection will work.

Wayne would be able to confirm.

If you decide to go ahead, would be happy to assist in getting it working.

Regards Phil.

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Re: ECB VDU [message #7216 is a reply to message #7210] Mon, 09 March 2020 18:11 Go to previous messageGo to next message
bifo is currently offline  bifo
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b1ackmai1er wrote on Mon, 09 March 2020 02:56
Hi,
The 8255 PPI controlling the keyboard and mouse port is not directly tied to the 6545 CRCT VDU controller.
There should be no port conflict between the two.
Yes you could omit the keyboard and mouse hardware without affecting the video hardware section.
On the software side, both video devices use the same keyboard driver and I don't think it supports multiple instances.
So I think the keyboard would only work on one device.
However with console redirection (FORCECON) you should be able to redirect all I/O to the VDU
Maybe even CP/M iobyte redirection will work.

Wayne would be able to confirm.

If you decide to go ahead, would be happy to assist in getting it working.

Regards Phil.
Is there still a mailing list which responds to forum threads? I only understand this place via what is an old school internet forum format. Always wondered about that.

As far as it goes, I built my N8 project but foolishly didn't think to buy the right cable from 8-pin to 9-DIN for rs232. Once I get it working, I hope to use the thing as a testbed.

[Updated on: Mon, 09 March 2020 18:16]

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Re: ECB VDU [message #7217 is a reply to message #7210] Mon, 09 March 2020 20:49 Go to previous messageGo to next message
Wayne W is currently offline  Wayne W
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Location: Fallbrook, California, US...
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b1ackmai1er wrote on Mon, 09 March 2020 02:56
Hi,
The 8255 PPI controlling the keyboard and mouse port is not directly tied to the 6545 CRCT VDU controller.
There should be no port conflict between the two.
Yes you could omit the keyboard and mouse hardware without affecting the video hardware section.
On the software side, both video devices use the same keyboard driver and I don't think it supports multiple instances.
So I think the keyboard would only work on one device.
However with console redirection (FORCECON) you should be able to redirect all I/O to the VDU
Maybe even CP/M iobyte redirection will work.

Wayne would be able to confirm.

Phil has it exactly right with one (sort of) exception. There is some rough plumbing in the ppk driver that (in theory) would allow it to support multiple keyboards. However, you will see that ppk.asm derives it's port addresses from a simple structure pointed to by IY when the keyboard functions are called. The corresponding video unit hosting the keyboard maintains this structure so that there could be multiple keyboards attached to multiple video devices all sharing the same keyboard driver.

Note that the video drivers themselves do not have this ability. So, there could not be two VDU boards sharing the same driver code at this time (could certainly be done with more code).

Any of the work proposed will require getting down and dirty with the RomWBW video/keyboard services. And there are some loose ends in that part of the code!

-Wayne

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Re: ECB VDU [message #7756 is a reply to message #7217] Fri, 05 June 2020 06:38 Go to previous message
eshazen is currently offline  eshazen
Messages: 2
Registered: March 2020
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Hi Folks- first time post! I'm interested in a 6845-based video board for my Z80 system, and the VDU looks like a great starting point. I'm curious if the V2 CAD files for the VDU were ever posted. The archives posted seem to be for version 1 and 1a. I use KiCAD myself and would be interested in possibly making some tweaks and getting some boards made. I would of course make freely available anything successful I produce.

I know about the VGA3 but I'd like to stick with the 6845 and an all thru-hole design if possible.

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