website/content/museum/tesla-pmd-85.md

title, categories, types, origins, years, cpus, params

title	categories	types	origins	years	cpus	params
Tesla PMD-85	Computers	Home Computer	Czechoslovakia	1985	MHB 8080A	name image company company_name specs tabs photos hardware emulators links comments oc_id source PMD-85 /media/museum/photos/tesla_pdm85_system_s2.jpg /companies/tesla Tesla label value NAME PMD-85 label value MANUFACTURER Tesla label value TYPE Home Computer label value ORIGIN Czechoslovakia label value YEAR 1985 label value BUILT IN LANGUAGE BASIC G cartridge label value KEYBOARD Full stroke 77 keys label value CPU MHB 8080A label value SPEED 2,048 MHz (Xtal 18,432 MHz divided by 9) label value RAM 48 KB (Mod. 1), 56 KB (Mod. 2A), 64 KB (Mod. 3) label value ROM 4 KB (Mod. 1, 2A), 8 KB (Mod. 3) label value TEXT MODES 25 lines x 48 characters label value GRAPHIC MODES 288 x 256 dots label value COLORS 4 (Black, White, Grey, Blink) - 8 for the PMD-85-3 label value SOUND 1 channel label value SIZE / WEIGHT 31.3 (W) x 26.5 (D) x 6.5 (H) cm / 1.915 kg label value I/O PORTS Serial, Parallel label value BUILT IN MEDIA None label value POWER SUPPLY Exxternal power supply unit, +5V, +12V, -5V, Max 35VA label value PERIPHERALS Tape recorder label value PRICE Unknown photos hardware emulators links title subtitle text image PMD-85-3 LARGE VIEW Thanks to **Jan Krupka** for the PMD-85-3 pictures /media/museum/photos/tesla_pdm85_system_s3.jpg title subtitle text image COMPLETE SYSTEM With the ROM module and the PMD-10 power supply unit. /media/museum/photos/tesla_pdm85_system_s4.jpg title subtitle text image REAR PANEL From left to right:\ • Tape recorder DIN socket\ • Serial V24 DIN socket. The PMD-85/3 had a special terminal mode allowing it to be connected to SMEP and RVHP (PDP-11 compatible) mainframes\ • IMS-2 (IEEE 488) connector\ • Universal parallel bus 0\ • Universal parallel bus 1\ • General I/O connector. /media/museum/photos/tesla_pdm85_rear_s1.jpg title subtitle text image ROMS MODULE /media/museum/photos/tesla_pdm85_romexpansion_s1.jpg title subtitle text image POWER SUPPLY UNIT It fits perfectly to back of the computer but unfortunately the design was not so great if you want to connect something to the I/O port. In that case it simply lays somewhere around.\ Early PMD-85 wasn't shipped this unit, a standard PSU providing +/-5V and +12V was used. /media/museum/photos/tesla_pdm85_pmd10module_s1.jpg title subtitle text image INSIDE THE PMD-85-3 The electronics od the PMD-85 consists of a logic card and an I/O card. **(1)** MHB 8255 for parallel interfaces\ **(2)** MHB 8253 timer\ **(3)** MHB 8251 USART, serial communication controller\ **(4)** 64 KB RAM chips\ **(5)** MHB8080 - CPU\ **(6)** MH 8228 - bus controller\ **(7)** 8 KB ROM chips\ **(8)** MHB 8255 - keyboard controller\ **(9)** Keyboard connector\ **(10)** Composite video output\ **(11)** TV RF modulator and output\ **(12)** External power supply connector. /media/museum/photos/tesla_pdm85_inside_s1.jpg title subtitle text image TESLA LABEL /media/museum/photos/tesla_pdm85_label_s1.jpg title subtitle text image KZD01 TAPE DRIVE This "intelligent" tape drive was mainly used with the PMD-85 as well as some other Czech computers.\ A special driver EPROM had to be installed inside the PMD program module.\ It used standard cassettes which must be "formated" before first use. Then it was possible to write or read from the drive. Sectors number identification allowed a direct access to the files. Thanks to **Jan Krupka** /media/museum/hardware/tesla_pdm85_tapedrive_s1.jpg title subtitle text image SP-210T CASSETTE DECK Despite its Japanese style, this cassette deck was designed and made by Tesla. It featured an advanced cassette deck as well as a slow (1 needle!) dot matrix printer.\ The SP-210 was same model but without the printer. /media/museum/hardware/tesla_pdm85_cassettedecksp210_s1.jpg title subtitle text image ARITMA MINIGRAF 0507 A4 plotter This small A4 plotter was widely used together with the PMD-85 as well as the IQ-151. In both cases it needed a special driver in EPROM.\ For use with PMD there was a set of EPROMs which must be inserted into the ROM module together with BASIC and monitor EPROMs. The Minigraf was connected to one of the multipurpose I/O ports.\ Later it was possibe to buy the Minigraf in some shops. There were also interfaces from Aritma for Atari XL and XE and for ZX Spectrum. Thanks to **Jan Krupka** for information and pictures /media/museum/hardware/tesla_pdm85_aritmaplotter_s1.jpg title url platform text PMD-85 emulator http://www.kmit.sk/~peto/ MS DOS Written Peter Chrenko (download includes games) title url platform text PMD 85 czech Emulator HTTP://WWW.SCHOTEK.CZ/PMD/PMD85V13P.ZIP Windows Other emulator title url platform text PMD 85 emulator http://pmd85.djb-studios.com/ Windows pages of win32 emulator of PMD 85 and compatibles title url platform text PMD-85 emulators http://www.schotek.cz/pmd/indexe.htm Windows DOS and various Windows versions. title url platform text PMD-85 v2 emulator http://pmd85.djb-studios.com/?module=dwl&did=1 Windows new version / developed by RM-TEAM title url platform text PMD-85 win-emulator beta http://dev.djb-studios.com/cache/pmdemu_v1.4b.zip Windows Written by Roman Borik & Martin Borik (include many progs and games) title url platform text PMD 85 hardware simulator/emulator based on AVR ATmega8515 with TV(PAL) output http://www.kmit.sk/~peto/AVR/smallpmd/index.php Other platform Nice PMD-85 clone title url text Martin Schotek PDM-85 page http://www.schotek.cz/pmd/indexe.htm Complete description of various PMD-85 versions (in English). author date text $$1040$$$1085$$$1076$$$1088$$$1077$$$1081$ (Russia) Friday 18th September 2020 This is my first wave...This B$W computer is to pretty... author date text pedrosk Monday 31st March 2014 my first ever touch was right here. I was 9 or 10 years old. Next step was ZX Spectrum and only later PP06 and today it is RasPI author date text Laco13 (Slovakia) Sunday 19th October 2008 This machine was my first touch with computer world on "Automation"-lessons on my highschool.\ I love this "comp"for good memoirs from that time.\ : - ))) author date text petera (Slovakia) Wednesday 23rd November 2005 Price in 1988: cca 12000,- Kčs = cca 1200 DEM author date text Linkman (Slovak Republic) Saturday 23rd April 2005 When i was young and i was in primary school we have computer lessons in primary school and we are playing lot games created for this computer. 730 url date https://web.archive.org/web/20230608091452/http://www.old-computers.com/museum/computer.asp?c=730 2023-06-08

The PMD-85 was a Czechoslovakian personal computer based on the MHB 8080A processor and manufactured by slovakian company Tesla Bratislava.

Several versions were available:
- PMD-85-1 (most common)
- PMD-85-2 (better keyboard and software)
- PMD-85-2A (new motherboard)
- PMD-85-3 (new motherboard again, pictured)
- Mato (kit of a clone in a smaller case)

This machine was well known among kids and fans for its presence in schools in 80's.

Thanks to Monty Jack and Jan Krupka from Czech Republik for info and picture.

---

The PMD series, by Andrej
Actually PMD series started much earlier. First one was PMD-81 (from 1981) followed by PMD-83 (of course manufactured in 1983-84) and the last one from series was PMD-85.
While PMD-81 (as far as I know) had just cartridge for Basic G, PMD-85 had as standard Basic G, but also Pascal cartridge was available.
Computer didn't have a monitor, it was plugged in regular (at that time B/W) TV.
While PMD-85-3 had prominent keyboard (as you can see in a picture), previous models had flat keys

Some acid remarks from David Cady:
In fact, this computer did not have a built-in language. That Basic G was a kind of a cartridge or a module, that can be seen and identified fairly easy on the picture provided on the page.
Above the keyboard, where the upper part of the rear panel begins, you can notice a slightly different colour of the case (the gray is a little lighter) with only one inscription on it in the upper right corner. Well, it's not the case anymore - it's that module! It was huge (in comparison to Atari or Commodore cartridges), quite heavy (almost one fifth of the total weight of the computer) and, surprisingly, fragile.

Probably therefore was this Basic G module shipped automatically with the computer (plugged in already - that might be the reason, why it's so often described as built-in).

Basic G was really bad, it was a very-low-performance clone of the Sinclair ZX Spectrum Basic programming language. Just imagine, that holding down the function key and pressing a letter key meanwhile wrote the whole command on the screen although there was no indication for the upcoming command on the keyboard itself (unlike ZX). It was very uncomfortable to get used to this and majority of those, who worked with PMD's didn't use this "fast commands writing feature".

The PMD 85/1 had a pretty miserable keyboard made of telephone keys (!). Writing a couple of A4's could become a blood-sweating experience.

PMD's were not really much cheaper in comparison to Atari, Commodore or ZX Spectrum computers (some of the peripherals were even more expensive than their 'western' equivalents), but they were the "official" computers for youth educating in computer science. Probably every other computer or programming club had several of those, so they became fairly widespread despite the quality.

PMD 85/2A, PMD 85/3 and Mato, Slovak successor to (and clone of) PMD 85/2, were basically the same shit. Sorry to say that, but I had to work with them, so I know, what I'm talking about. I didn't like ZX's, but I'd prefer them anytime to PMD's.

The peripherals - similar to ZX, any casette player/recorder could be plugged in. There was a special peripheral from Tesla that combined the tape recorder with a printer (the D-100 model or the BT-100 model). This printer had a single-pin head and you had to put a carbon paper (!) in between the head and the clean paper for the printer to work correctly - to print at all! That's what I call innovative approach :-)