Галаксия (Плюс): сборка и настройка

[fifan]

No Problem, I'll Wait. For the keyboard I have made a little adapter, that emulates keyboard matrix from a PS2 keyboard. It is based on MT8816 and PIC16F1459. I'm waiting for PCB boards for my keyboard to come from China.

Зачем так сложно. У меня весь адаптер поместился в один PIC контроллер. Начну отладку как запущу основную плату.

[Sajmosia]

Is the scheme and firmware of this device in the public domain?

No, this is something I built myself. The MT8816 Chip is fairly easy to use and provides true matrix.

[Sajmosia]

Зачем так сложно. У меня весь адаптер поместился в один PIC контроллер. Начну отладку как запущу основную плату.

I needed something that I can use with other designs as well without having to reprogram the chip. PIC16f41459 apart from control of the matrix gives me I2C for 24LC512 to store map tables and USB to program and upload new maps. I'm planning to use that matrix with other machines as well as Галаксия.

Here is a short video testing the keyboard with clone of computer called Cobra:

https://www.youtube.com/watch?v=bbGV6k1XZAA

Here is the same emulating terminal for computer Bosman 8:

https://www.youtube.com/watch?v=U3gRtLO8PTQ

Thanks.

[fifan]

Thank you for the video, but nothing is clear from watching the monitor. First of all, you need a scheme of the device and its algorithm. On retro computers from the former USSR has long been used PS/2 keyboard adapter from Vinxru. It consists of only one chip. I am not a fan of Atmega controllers so I will make a PS/2 keyboard adapter on the PIC controller.

At Galaksija, we have decoder lines, polling the keyboard and the multiplexer columns of the answer. Our task is to convert the PS/2 keyboard code into the keyboard response code. I think this is not such a difficult task.

Sorry for my English. I use an online translator.

[PVV]

Сегодня в магазине проходил мимо полки с коробочками для продуктов и увидел такое:

как по мне, подходит отлично



цена вопроса ~1$
мгтф на плате это переделка на кварц 12МГц, клавиатура будет не с картинки, но будет сделана по аналогичной технологии.

Что то никто не задумывается об подключении звукового чипа AY3.

и вот так я вижу размещение элементов

платка получается примерно 35х70мм.

по схеме PSG хочу еще отметить два момента.
- У нас на системном разъеме нет сигнала /RESET для AY, который должен приходить на 23ю ножку, я на схеме сделал его формирование локально на R8 и C5, а на 29й ножке системного разъема его обозначил на всякий случай, если со сбросом возникнут проблемы, то можно эту цепь задействовать. В плате Галаксии на 29 ножке сигналы другие. На собранное плате PSG соединения 23й ножки AY с 29й ножкой разъема нет.
- Второй момент, у меня звуковой чип не AY3-8910, а YM2149F и в данный момент кварц в Галаксии используется 12МГц, а не 6.144МГц, из-за чего на CLKA у мена повышенная в два раза частота, но у YM2149F есть особенность, если её 26ю ножку посадить на землю, то в YM2149F включается внутренний делитель CLKA на два, и частота тактирования звука становиться правильной. Соответственно 26ю ножку звукового чипа при кварце Галаксии 6.144МГц на землю садить не надо.

[PVV]

Не знаю даже, что на меня нашло... вот результат:



разъема на плате Галаксии у меня нет, но и так все контачит, если немного под углом вставить, все играет!

плеер здесь
во вложении pdf для ЛУТа.

[fifan]

А где сам файл PT2PLAY.GTP - я его не нашёл, в образе диска?

[PVV]

А где сам файл PT2PLAY.GTP - я его не нашёл, в образе диска?

да, все в образе, а еще, в том же архиве исходники есть, можно самостоятельно собрать.
PTXPLAY.GTP это универсальный плеер, и PT2 и PT3.

во вложении сами плееры

[msolajic]

Hi everyone!

First, i'd like to thank PVV and Fifan for such an awesome project!
(Oh, and sorry for posting this in English, I do understand some Russian but not enough to write what I'm about to)

I had some issues while getting the Galaksija to run. First, none of my monitors would sync. I have experimented with values of R12 and C3, and came to conclusion that either you can increase R12 to about 2k or you can change C3 to 22n to get stable image on screen.

After this problem was sorted, it looked like everything is working, but I couldn't get full initialization (either blank screen or READY without the ">" in the next line. BASIC programs, sort of, worked, but only in "minus" mode. In Plus mode, either text or graphics mode, everything was acting funny. Simple BASIC programs would not run in a loop. The screen editor would get confused at times. I beleive Pluto had similar issues. See video:



After reading trough this thread (again and again) i tried a similar approach - to lower the input voltage. When it was about 4 volts, I could get everything working. I even loaded games from the SD card, and while it seemed to work, I had some glitches on the screen in the graphical mode. See image:



At first I tried changing almost every TTL chip I could find a spare. Nothing. Since I suspected it is a memory problem, and I didn't have a second RAM chip, I tried it with a 6264 chip. It actually worked without any problems, on 5v power supply. After some interesting glitches on the screen (unfortunately, I don't have an image or video of that) I noticed that I got a "wrong" memory block displayed - on the screen I saw the content of the keyboard input area. I started to analyze the memory decoding circuit and decided to try something. After swapping the pullup resistors in the memory decoder to 1 kiloohm (namely, R35, R36, R37 and R48) all of my problems were gone! Everything was working fine - Regular (minus) mode, Plus mode, Graphics, everything! Video proof is here:



After checking the schematic, I should probably change R39 to 1 kiloohm too, but the SD card is working fine.

Oh, and one other thing. After removing C19 and C20 (and making a short across one of them) the picture on the screen is rock-solid. Of course, for better brightness, R9 must be replaced with a 1k resistor.

I also made a PS/2 keyboard adaptor, with an Arduino Nano and MT8816. After I get the first PCBs done and confirm everything is working, I'll share the design here, as a thank-you to everyone involved.

Again, a big thank you to everyone that is involved in this project!

[PVV]

Поздравляю с успешным запуском!

I had some issues while getting the Galaksija to run. First, none of my monitors would sync. I have experimented with values of R12 and C3, and came to conclusion that either you can increase R12 to about 2k or you can change C3 to 22n to get stable image on screen.

Резисторы и в особенности конденсаторы имеют очень большой разброс(+20%, -50%), равно как телевизоры могут подстраиваться в широких пределах, но иногда случаются несостыковки, главное есть способ решения этой проблемы.

After reading trough this thread (again and again) i tried a similar approach - to lower the input voltage. When it was about 4 volts, I could get everything working. I even loaded games from the SD card...
At first I tried changing almost every TTL chip I could find a spare. Nothing. Since I suspected it is a memory problem, and I didn't have a second RAM chip, I tried it with a 6264 chip. It actually worked without any problems, on 5v power supply. After some interesting glitches on the screen (unfortunately, I don't have an image or video of that) I noticed that I got a "wrong" memory block displayed - on the screen I saw the content of the keyboard input area. I started to analyze the memory decoding circuit and decided to try something. After swapping the pullup resistors in the memory decoder to 1 kiloohm (namely, R35, R36, R37 and R48) all of my problems were gone! Everything was working fine...

Это весьма интересная и ценная информация, и логично объясняет причину 'нормальной' работы при пониженном напряжении питания. Надо в первом сообщении уточнить, что номиналы этих резисторов надо уменьшить с 10К до 1-2К.

Oh, and one other thing. After removing C19 and C20 (and making a short across one of them) the picture on the screen is rock-solid. Of course, for better brightness, R9 must be replaced with a 1k resistor.

разные телевизоры могут по своему реагировать на наличие или отсутствие C19 и C20, так что лучше на плате их предусмотреть(как здесь), а при необходимости их закоротить(выбросить). Да и за номинал R9, так же надо в первом сообщении уточнить.

I also made a PS/2 keyboard adaptor, with an Arduino Nano and MT8816. After I get the first PCBs done and confirm everything is working, I'll share the design here, as a thank-you to everyone involved.

будет интересно. В моих 'планах' аналогичная работа стоит, но не скоро .