Portable Tatung Einstein Emulation with ColecoDS

[+wavemotion]

And here's something sure to appeal to almost nobody

 

I finally got around to writing a WD1770 floppy controller emulator for ColecoDS (https://github.com/wavemotion-dave/ColecoDS)

 

This emulator supports the Colecovision / ADAM and 10 other related systems all sharing similar hardware (MSX1, Sord M5, MTX, SG-1000, etc).

 

Version 8.6 released today is all about support for the Tatung Einstein - a high-end Z80 computer often used by developers in the 80s to write software for other machines.

 

Tatung Einstein Compatibility :

The base 64K machine is emulated. Both .dsk files and .COM files will play. For both, you would load the file and press the START button to boot them (for .com files, it will load the file at 0x100 and auto-run... for .dsk files the START button will emulate the CTRL-BREAK needed to boot the diskette). Out in the interwebs, you will mostly only find .dsk files and the .COM files can be extracted from them. The easiest way is to use either Charlie Robson's einSDein-vitamins or EDIP to extract .COM files from disk images. Or just stick to .dsk files which are a bit more authentic to the experience of using a Tatung Einstein.

 

Two Tatung Einstein disk drives are supported. The default drive 0: is a standard single-sided, 40 track, 10 sector-per-track diskette with about 190K disk space available. This is the drive that will hold and load your .dsk file image when you run the emulation.

 

The second drive 1: is a persistent RAM Disk that can be saved back to the SD card on your DS/DSi. This comes pre-formatted (and you can re-initialize it using the DISK icon menu) with 190K of storage. To the emulator, it looks just like a standard second disk drive. You can copy often used programs and utilities to this disk - I use it to stash away a few flavors of XBAS so I've always got the right one on hand to play games.

 

Both drives support read/write capabilities however, the writing will NOT auto-back those changes to your SD card. I might change that behavior in the future - but for now, any changes written to the emulated disks are transient until you go into the DISK icon menu and save them back to the SD card. I'm fairly confident that the disk write works fine - but until I get more testing hours from field-use, I don't want to inadvertently screw up an original .dsk image and leave the onus on the user to save out the disk for now.

 

As an aside, I couldn't get the Tatung Einstein driver for MAME to handle proper disk writing - and have seen that others have struggled as well. Given that MAME is the only other Tatung Einstein emulator on the planet, it's possible that ColecoDS is the first to support full read/write of the Einstein's 3" disk format.

 

Speaking of disk images, there are several places to find them... but I would recommend seeking out the 'Tatung Einstein Gamebase' which generally has disk images properly formatted and auto-booting for a more streamlined experience. Seek those out.

 

Lastly, in addition to the standard 8K einstein.rom BIOS file (required for Einstein emulation), you can optionally provide an einstein2.rom file that will load (up to 8K) into 0x4000. This is the extra ROM slot in a real Einstein and can be used to house diagnostics roms or things like flexi-dos.

 

 

[wtj._]

theres absolutely no BIOS ROM mentioned anywhere on the internet. i've been trying for ten minutes. do you have any?

[+wavemotion]

You can search for the MAME merged set and pull the bios for the Tatung Einstein from there (either v1.2 or 1.2.1). Be sure to name it correctly for ColecoDS. I forget off-hand which one I did most of my testing with... but either should work.