Another rare brazilian coco clone...

[Dantyr]

Hello,

Last week I aquired another rare brazilian coco clone, the Dynacom MX-1600:



It came on bad shape and not working, but after some work, it's fully functional again.
It has several improvements like a pause switch and a monochrome video output. The joystick ports are Atari VCS compatible.

More pics: https://picasaweb.google.com/1093456998 ... acomMX1600#

Here are the Color BASIC and EXTENDED BASIC ROM dump.

Regards,
Daniel

[Alastair]

It has several improvements like a pause switch [snip]

You mean that it can freeze any running program with a flick of a switch? I wonder if a Dragon can be modified to do the same...

[Dantyr]

Yes, It's exactly a freezing switch.

I think there is an article on the Rainbow Magazine explaining how to add a pause button on a normal Coco.

Daniel

[zephyr]

Hello,

Last week I aquired another rare brazil ... m MX-1600:

Here are the Color BASIC and EXTENDED BASIC ROM dump.

Thanks Daniel!

You mean that it can freeze any running program with a flick of a switch? wonder if a Dragon can be modified to do the same...

All you need to do is ground the HALT pin (40) of the CPU through a switch or button. You can safely keep the computer halted indefinitely without loss of data.

[zephyr]

Here are the Color BASIC and EXTENDED BASIC ROM dump.

The MEM function has been hacked to display 57383 BASIC bytes free at power-up, even though the top of memory available to BASIC is set to $7FFE as normal.

Someone has put a JUMP at $B4F0 to a slightly modified version of the MEM function code at $A148 - $A162. The original COLOR BASIC 1.2 [$0D] (C) 1982 TANDY [$00] message is usually stored at $A147 to $A165. The hacked routine always adds #$7F00 to the current stack pointer address. If the returned PRINT MEM results were true, entering "CLEAR 0" at the BASIC command prompt would (theoretically) put the top of BASIC at $FEFE (&H7FFE + &H7F00). This, of course, is impossible. I wonder if this is a bug, or a joke!


Here is a copy of the mx1600bas ROM image with the above mentioned MEM function bug fixed.

[robcfg]

Excellent work, Daniel!

Do I have your blessing for uploading your rom dump to the people of MESS? It's one of the systems for which they don't have the roms yet.

Regards,
Rob

[Dantyr]

Excellent work, Daniel!

Do I have your blessing for uploading your rom dump to the people of MESS? It's one of the systems for which they don't have the roms yet.

Regards,
Rob

Sure!! That was the idea!

We need to preserve that stuff, because sometimes is very difficult to find a working machine to do that.
In the brazilian retrocomputing community, I only know another person who has this machine and it have keyboard problems.

Regards,
Daniel

[robcfg]

Ok, if you don't mind then I'll be sending the MX-1600, the Color64 and the CP400 roms.

I guess the CP400 roms are from the CP400 Color and not the CP400 Color II, right?

Besides that, the remaining brazilian clones to be dumped would be the following:

CP400 Color II (Brazil)
Varixx VC50 (Brazil)
Codimex CD6809 (Brazil)

Keep up the good work!

Edit:Sent the current Brazilian clones roms to MESS

[robcfg]

Daniel,

I'd need you to tell me for the three systems (Color64, CP400 and MX-1600), which kind of eprom type and how many they have.

I see in your pictures that the MX-1600 has only one 16kb eprom, so from MESS viewpoint, its rom files should be in a single file.

Again, thank you very much!

[Dantyr]

Daniel,

I'd need you to tell me for the three systems (Color64, CP400 and MX-1600), which kind of eprom type and how many they have.

I see in your pictures that the MX-1600 has only one 16kb eprom, so from MESS viewpoint, its rom files should be in a single file.

Again, thank you very much!

Sorry, I'm late..

The Color64, the EPROMs are covered by a label and I don't want to removeit. But as they had 24 pins and are plugged on piggyback, I imagine it uses 4 MCM68A332 of 4Kb each, completing 8Kb on each bank. LZ made that on the time possibly because of the lack of the original MCM68A364 of 8Kb, as used on the Coco1. Pic bellow:



The MX-1600 uses a common 27128 of 16Kb as seen bellow:



CP-400 have two models, but I think they uses two 2764 as seen on this image bellow (that is the one CP400 model II PCB):



Unfortunatelly, I don't have any of the CP-400 models to confirm that.

Daniel