Mar 082018
 

As many of you collectors/enthusiasts may know, the FM Towns Marty is  is a  home video game console released in 1993 by Fujitsu, exclusively for the Japanese market. It was the first 32-bit home video game system, and came complete with a built in CD-ROM drive and floppy disk drive (able to read 1.2MB formatted disk like other japanese systems). It was based on the earlier FM Towns computer system Fujitsu had released in 1989. The Marty was backward-compatible with older FM Towns games :

 

 

A later model called Marty 2 was released in 1994 but it was essentially the same hardware (darker grey shell apart)

Game list includes many Japanese versions of great PC games, such as Indiana Jones and the Fate of Atlantis, Wing Commander II, Ultima VI, Monkey Island II, and so on.But this console is well known also for having many arcade-perfect ports like Splatterhouse, Tatsujin Oh, Raiden, Super Street Fighter 2, Viewpoint and other.Most of its software is on bootable CD-ROM but some games require both a CD and a floppy disk, so even if a burned CDR is used, a correctly formatted floppy is also required.Sadly the floppy drive is a weak point of this console, in best of cases the drive belt may melt over time but the unit is considered fragile and no spare are available.Luckily nowadays FDDs can be replaced by emulator and in this article I will explain how to use an HxC SD floppy emulator (by Jean-Francois del Nero) in a Marty (or Marty 2 like mine) console.

The original FDD of the FM Towns Marty console is a EME-215FS manufactured by Matsushita with a 26PIN FFC connector and cable (1.25mm of pitch) :

No info were available about so I first analized it and came to the conclusion that its pinout was the same of a slim 26PIN FDD for PC which comes with a FFC connector too but pitch is 1.00mm ( pin 13 and 21 are GND on Marty)

Based on the above pinout I figured out the connection diagram to the HxC (or a real 34 pin FDD able to handle 1.2MB formatted disks)

Obviously some kind of adapter was needed.Not having a spare 1.25mm FFC connector I ended up to remove the one from original drive and build an adapter to 34 PIN IDC (the 4 pin connector is for powering the HxC) :

I carried on the first test on a Samsung SFD-321B FDD (modified to work as Shugart drive) and it worked, I  was able to read/write/format 1.2MB 3.5″ floppies :

But I was not able to do the same with the HC floppy emulator.After some emails exchanged with Jean-Francois del Nero (a.k.a. Jeff, the designer of the HxC) we found the issue.The READ DATA signal (output from pin 30 of the HxC) was quite slow to rise up in his opinion:

He suggested me to install a 220 Ohm pull-up resistor between pin 30 and +5V (actually FDD outputs are already pulled-up with 2.2K resistors so a further 220 Ohm one put in parallel lowers the resistance to VCC to about 200 Ohm).This corrected the signal to what Marty expected to see:

Doing so finally I got the HxC flopy emulator working with my Marty console!Here are a couple of video I made during reading and formatting operation (sorry for black&white picture but my TV cannot accept NTSC signal)

 

As for the HxC configuration file you can set the interface on “Auto” or ” Generic Shugart” and all other settings on “From HFE”

A big thanks again to Jeff for his wonderful device and support (and patience with me too..).

 Posted by at 3:48 pm
Mar 042018
 

I recreated this late last year but haven’t been able to test until recently.
This is the last missing dump from the MK2 hardware.
The ID is A-17481 and is located on the sound PCB.

Thanks go to JokerCK for lending me his GAL chip to reversing. Also big thanks to JonHughes for confirming the recreation worked for someone other than me. Finally thanks to my good friend Paul for stripping his PCB out of his cab for me to do some testing on.

 Posted by at 12:48 pm

Backing up an old BBC Micro cassette tape

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Feb 252018
 

My friend was wanting to backup an old BBC Micro cassette tape that he believed had a game on it his grandad had made. The tape was marked up as “The Wizards Mountain”

I’d never backed up a cassette tape before and I didn’t even own a tape player anymore.
I originally tried buying a really cheap and nasty portable tape player

This was a total disaster and I kept getting inconsistent reads on various parts but between several reads I had what looked like a complete good read.
Using the ‘BBCTAPEDISC’ program I was able read the data directly from the ‘line-in’ source and it also gave a live update on each block recovered so I could see what was failing.

I originally tried stitching different parts together to make a good file but I just couldn’t get it to work properly so I asked around to see if I could borrow a better tape player. Fairly quickly I ended up with this

This gave me an almost perfect read first time. I ended up with a disc image instead of a tape image but thats fine with me as it loads faster.
The outcome is a text adventure game that appears to have been made with GAC.

Its actually a nice story which I still need to finish once I get some time but we are both really happy to have this saved.

 Posted by at 9:26 am

Vanguard repair log

 PCB Repair Logs  Comments Off on Vanguard repair log
Feb 242018
 

Bought this classic as not tested but luckily it was working except the missile sound was completely missing.

Looking at the schematics I found this

 

 

In the game there are only two missile sounds.

Shot A is your ship missile sound, while Shot B is the one from some enemies

IC37 is an LM3900 op amp which is very unreliable and infact after changing it , the missile sound was restored

Labyrinth Runner repair log

 PCB Repair Logs  Comments Off on Labyrinth Runner repair log
Feb 242018
 

The game was working good except the sprites were all missing some lines

 

The board is using some unreliable drams 41464 from Fujitsu similar to the ones used on Konami Haunted Castle or CPS1 A board.

I bought some units from Aliexpress , put some handmade socktes and changed both to be 100% sure

Turned out only one of the two was faulty, in anycase the graphics were 100% fixed