Home Page Forums MAME MAME Playing with the Atari 2600 POP

Ok, I put up my compumate branch if you would like to have a look:

https://github.com/goldnchild/mame/tree/compumate

I read about a computer that was based on the Atari 2600 called the BIT60. It had a an "enhanced" mode that would run a version of basic.

Unfortunately, there's very little information to be found on the BIT60.

However, in searching for info on the BIT60 I happened upon a lot of information on the BIT90 which is a colecovision clone, and there's a mame driver for it even!

Since I was able to hack in cassette support for the Compumate, why not try to do the BIT90?


After adding a few lines of code, I was able to load a save.


Using a demo.wav as reference, the system seemed a little slow, removing the wait state seemed to get it closer.

I had to clean up demo.wav by running a bunch of normalization in Audacity because the beginning was too quiet and DC biased.

The demo program was pretty nicely done showing off the capabilities of the BASIC with sprites and music.






3 tracks in audacity, top = normalized demo.wav, middle = original demo.wav, bottom = demo.wav loaded into mame, then saved out



length of mame loaded/saved wav is really close to original

I own a BIT90 (from fleamarket, no accessories). The thing could play Colecovision carts, but had a hardware flaw that prevents proper use of the keypad of my original Coleco joysticks due to mux with the computer keyboard in some games ("Rocky"?). In 1990th I had wired an inductor (coil) into one of the data lines to the joyport to distort a signal enough to delay its recognition and so prevent the clash. I don't remember the details, but the coil is still inside.

Ok, I put my branch on github if you'd like to take a look:

https://github.com/goldnchild/mame/tree/bit90_cassette





I also made a softlist for the Spectravideo Compumate cassettes, and that was actually much harder than I thought it would be to make one from scratch.

Props to the softlist makers.

Ok, I think I managed to get the cart/ram switching working properly on the BIT90 using a view.


with cart:




and with no cart, you get the basic screen, with ramsizes of 1024, 16k and 32k working.

The FRE command says that you have 761 bytes, 16377 bytes and 32760 bytes free for the various ram sizes.

Trying to get the BIT90 printer to do something, it's a total hack but it looks recognizable.

I came across the TI-99 PHP1900 Thermal Printer and thought I'd give it a try.

I made a thread over at atari age forums if you're curious.

https://forums.atariage.com/topic/381636-php1900-printer-emulation/

I never bother with that forum now since it's owned and run by the new Atari owners. Too much censorship going on there. To them emulation is evil and roms are illegal.
Not sure why you would even bother posting TI99 stuff there, let alone anything MAME related.
Keep MAME wip here where there are people interesting in emulation.

The printer in the Rockwell (later Dynatem) AIM-65 might also be using the EPN3116C, but I can't find schematics of the printer itself offhand.
(This is also not yet hooked up in MAME)

Schematics of the AIM-65 printer

http://retro.hansotten.nl/6502-sbc/aim-65/aim-65-40/

edit: oh that's a different unit

from an article:

The AIM-65 computer motherboard also sports a very interesting and compact Thermal
Printer module, made by Shimadzu in Kyoto, Japan. Their company goes back to the
1870’s and they became experts in high quality medical electronics. This extraordinary,
compact and brilliant printer module was also used in equipment made by Tektronix. It
is the subject of another article I’m working on, under construction. This printer is worthy
of an article all on its own. It is quite an exceptional little machine).



Schematic of the aim65 printer interface is in the user's guide, page 7-21 along with a detailed explanation of how the printhead works.


https://www.commodore.ca/wp-content/uploads/2018/11/rockwell-aim65-user-manual.pdf


how to print graphics on the aim65 printer:

http://archive.6502.org/publications/aiminteractive/aim_interactive_2.pdf