EF9365 / EF9366 / EF9367 video

Description

Just a collection of information about this chip and boards that use it. So far, I'm only aware of two boards, the GDP-64 by Rolf-Dieter Klein and the Elektor high-resolution colour graphics board.

The Elektor board is a more convenient sized 160x100mm Eurocard, and is extensively documented in various language editions of the magazine, so it is the better design.

The pixel clock is 12 or 14 MHz. The pixels are not exactly square, but that is only desirable in pixel graphics.

Most television circuits would not have the bandwidth or phosphor-dot density to support 80-column text. A monitor would be a wiser option, if you can get one.

Details

The chip itself is not great. Its predecessor the EF9345 was only a text video sequencer, and the EF6366 is only a graphics video sequencer that draws text on a graphic screen.

Not suited for new designs.

In Rolf-Dieter Klein's book, Mikrocomputer Selbstgebaut Und Programmiert, page 264, there is some Z80 source code for the EF9364, which I assume is a very close predecessor to the EF9365. German comments.

If I wanted to experiment with this chip I would buy a modern reproduction of the GDP-64 board and interface its bus to whatever other bus I was using, or recreate the Elektor board.

Files

ESS-543-source-b000.txt

Reverse-engineered source file for the Elektor Colour Graphics Card software in the Octopus system. Creates the bytes listed in Elektor March 1986, pages 68 and 69. There may be some OCR errors!

plain - 32.32 kB - 06/11/2023 at 15:59

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ESS-543-hex-b000.txt

Source file for the Elektor Colour Graphics Card software in the Octopus system. Consists of the bytes listed in Elektor March 1986, pages 68 and 69. There may be some OCR errors!

text/plain - 16.69 kB - 06/11/2023 at 19:25

Download

ESS-543-IC10.txt

Source file for the Elektor Colour Graphics Card IC10. Row Address Decoder. Could be replaced by a PAL16L8.

plain - 811.00 bytes - 06/11/2023 at 15:37

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ESS-543-IC30.txt

Source file for the Elektor Colour Graphics Card IC30. High-speed timing controller. Could be replaced by a PAL16L8. A PAL16R8 could replace IC10 and IC16.

plain - 1.33 kB - 06/11/2023 at 15:37

Download

MC-Grafik-Terminal.z80.txt

Source code made by adding information from the article to the disassembly. Assembles online at asm80.com and binary output verified the same as the original 1200 baud ROM. NB the magazine listing has 9600 baud.

text/plain - 110.40 kB - 04/03/2022 at 03:49

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Project Logs

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Ralph-Dieter Klein's GDP64K
Keith • 06/12/2023 at 22:23 • 0 comments

Circuit diagram

The 25LS2538 chip is somewhat like a 74LS138, but also able to assert all eight outputs at once. No longer made or commonly available. The Elektor design replaced it with a fast 32-byte PROM (82S123). It could also be replaced with a PAL16L8 chip.

Original board:

2017 reproduction:

Has a phono video output socket and a modern crystal oscillator module.
Elektor high-resolution colour graphics card
Keith • 05/14/2022 at 16:09 • 0 comments

This is a Eurocard sized board, and extensively documented in seven parts, in the UK magazine version dated September 1985 to March 1986.

All parts are available on the official Elektor website, but you have to be a member to access them:

high-resolution graphics card - 1 Introduction
high-resolution graphics card - 2 More introduction
high-resolution graphics card - 3 Circuit description (has the circuit diagram)
high-resolution graphics card - 4 Construction (has the copper and silk screen patterns)
high-resolution graphics card - 5 General programming information
high-resolution graphics card - 6 Colour extension board
high-resolution graphics card - 7 Graphics interpreter software

Available online as scanned archives:

high-resolution graphics card - 1
high-resolution graphics card - 2
high-resolution graphics card - 3
high-resolution graphics card - 4
high-resolution graphics card - 5
high-resolution graphics card - 6
high-resolution graphics card - 7

And in Dutch:

grafische kleurenkaarte - deel 1
grafische kleurenkaarte - deel 2
grafische kleurenkaarte - deel 3
grafische kleurenkaarte - deel 4
grafische kleurenkaarte - deel 5
grafische kleurenkaarte - deel 6

You will have to search for non-restricted material. Try https://worldradiohistory.com/

I had a go at OCRing the hex dump in order to disassemble the software, but the OCR error rate was so high it would have been quicker to read and type in the values. Even then, the image quality means some characters are hard to read. I ordered a copy of the 1980-1989 Elektor magazines on DVD in the hope that they will be much better quality, enough to extract the hex data.

For 25 euros, you no longer have to make to with poor quality scans and incomplete collections on the web.

The quality is much better indeed. The articles also have embedded OCR text, so it is possible to copy and paste that. The hex dump text had errors, but these were easy to spot and correct. I disassembled the hex data and created a source file that assembles to produce the original hex bytes.

Circuit diagram:

The hard to find 25LS2538 has been replaced by a high-speed (50ns) 32-byte PROM (IC10), the 82S123.
This could now be replaced by a PAL16L8 or GAL16V8, which is more commonly programmable by hobbyist device programmers.
Another such PROM (IC30) works with a 6-bit latch (IC16), the 74LS174, to form a state machine generating the video timing signals. The PROM could be replaced by a PAL16L8. Both PROM and latch could be replaced by a PAL16R8 or GAL16V8.
The article includes the bytes for these PROM chips, so it was easy to create source code and binaries for them.
MC Graphic Terminal
Keith • 04/02/2022 at 15:11 • 0 comments

This is a nicer design which has a Eurocard size board, DIN41612 connector, and a Z80 processor. It communicates through serial ports, and only draws 5V, +12V and -12V power from the DIN41612 connector. So it can be easily adapted for other buses with those rails.
The crystals look a bit precarious, I would change them for lower-height versions.

There is 8K of firmware, implementing a graphics terminal. I'm sure the design could be greatly expanded.

It uses two Mostek MK3801 chips to provide I/O and timers. These were never popular and are hard/expensive to get in 2022. This adds a hurdle to recreating this board.

One MK3801 is used for parallel I/O and a computer terminal. The other is used for a keyboard and can be omitted if there is no keyboard. Serial ASCII keyboards are long obsolete so the second MK3801 is unlikely to be needed.

View all 3 project logs

Discussions

Smed wrote 04/27/2023 at 13:04

Lightpen for EF9366 - cool!

https://hschuetz.selfhost.eu/ndr/hardware/neu/sonst/lightpen/pen.pdf

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Smed wrote 04/27/2023 at 12:41

Two games that I have implemented using the EF9366 on a 68008-8Mhz machine.

https://youtu.be/xPywh_BirmM

https://youtu.be/s3QR7va91kg

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fjkraan wrote 04/02/2022 at 12:44

For a very long time, I have a Z80/EF9366P based graphical terminal eurocard-board for the ECB bus, but it only uses the power lines. The upper half looks very much like your boards, a Z80 with memory takes the other half. It has RDK as initials on the board, so it is very related. It was described in two MC-magazine articles: https://electrickery.nl/comp/divcomp/doc/mc-Grafik-Terminal.pdf.

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Keith wrote 04/02/2022 at 12:52

Thanks for the info. These are not "my" boards, but R.D. Klein's. I had a look at your pdf and largely converted it to html so google can translate it. Only taking the power lines from the bus makes it easy to port to other buses :-)

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ljheidel wrote 01/09/2022 at 12:08

I've done a "new design" with this chip's predecessor (EF9345) for Z-80 retrocomputing. It's "not great" but it looks like it will be good for basic 80 column video since I was able to get it working with only 5 chips (2 of which were already present in my system). It took me about a day to figure out how to interface it and build the circuit. Still working on the software. I've written a rudimentary C library, and built some ASM code that's going into my CP/M BIOS, but it's a work in progress.

I have an older Dell 20" LCD display that was pretty fancy for it's day. With a little bit of coaxing, it will sync up to this at both 50Hz PAL and 60Hz NTSC timings through the VGA port with nothing to interface it but voltage-dividing resistors on the RGB lines. It scales the picture, so it doesn't look great, but it works. I'm looking for a better solution. This would preclude it from being used comfortably for any length of time.

If you're interested, I can share my code, design and notes.

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Keith wrote 01/09/2022 at 20:51

https://hackaday.io/project/182423-ef9345-video for that chip.
It was used for the Dutch Acorn Atom Club's 80-column card.

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EF9365 / EF9366 / EF9367 video

Description

Details