PMD85 v2

Computer PMD 85 is Czechoslovakian 8-bit computer produced by Tesla Piešťany and Tesla Bratislava. First version was designed by Roman Kišš. And this is its implementation in Verilog for MISTEer FPGA.

Short demo video of this core on youtube

https://youtu.be/VVukIzzWiKY

Specifications

• CPU MHB8080A @2.048MHz - Czechoslovakian clone of Intel 8080
• 64 kB RAM
• 4 kB ROM + up to 32 kB in detachable/changeable ROM pack used for example for Basic but also might be used other devices like emulator of 8048 uProcessor
• TV output or RGB video
• 288x256 pixels - 2 bits "color" attributes per 6 pixels (grayscale or blink or RGB)
• 2x8-bit parallel bus connectors
• application connector directly connected to IO system bus
• IMS-2 connector
• current loop RS232 connector
• connector for tape recorder to store and load programs

What is implemented

• CPU
• 64 kB RAM
• Keyboard
• Beeper
• Green monitor mode, TV mode, RGB mode
• Color ACE mode - homemade color
• loadable ROM Pack via menu for loading SW - *.rmm files needed
• MIF85 sound interface
• tape load via ADC MISTer connector (line in)
• mouse
• MHB8251 (i8251 clone) UART
• All RAM mode (when all ram mode is activated, green led is blinking)

What is missing

• floppy!!
• virtual cassette player (ptp files)

How to install core

• copy file PMD85_########.rbf from releases folder to your MISTer SD card to Computer folder (######## stands here for date of version - you might want to delete earlier from SD card if you have some)
• create subfolder PMD85 in games folder on SD card and put there *.rmm games files you have
• in MISTer menu navigate to PMD85 item and start the core

How to start

Options

• Enable MIF85 in menu in sound item before load to be detected by SW and used
• Joystick and color mode can be changed during SW runs
• Mouse can be changed too, but SW probably do mouse presence test at start

Loading games via ROM Pack

• In menu choose *.rmm file you want to load
• Reset PMD - rom pack usually contains automatic load
• Enjoy the PMD and the game :)

Loading games via ACD (audio line in)

• connect your audio source (cassette player, mobile, ...) to MISTer ADC (line in)
• type MGLD ## and type EOL. ## replace with number of game you want to load. If you don't know game's number put there 00 and watch what PMD type on screen when loading, then reset and use that number for loading
• start playing WAV file. Games might have loaders and might draw a picture during load
• Enjoy the PMD and the game :)

Connect your PMD core to serial console (optional)

• this is optional - just in case you want to try to communicate with other world
• You need MISTer user port cable with UART to USB converter. Please mind MISTer FPGA uses 3.3V logic and your converter MUST support it. Otherwise you will destroy your MISTer!
• On PC run some terminal program (Hercules, Hyperterminal, ...) and set 4800 Baud, 8 data bits and Parity None (this is for monitor console)
• In PMD monitor (after reset) press Shift + STOP keys (Shift + TAB). This turns on PMD console

Demo video of this feature on real HW is here (this is NOT my video)

https://www.youtube.com/watch?v=pJfnra3cwgY

- Once again: Please mind MISTer FPGA uses 3.3V logic and your converter MUST support it. 
- Otherwise you will destroy your MISTer!
- I've warned you and you do it at your own risk!

Here is simple picture how you should wire your MISTer to UART-to-USB converter. And here is bigger picture as plugged into MISTer.

For more info see

• http://www.sapi.cz/pmd-85/pmd85-2a.php
• https://en.wikipedia.org/wiki/PMD_85
• https://pmd85.borik.net/
• https://www.schotek.cz/pmd/

Some of them are only in Czech or Slovak, but Google translator is your friend :)