master 6801

[chart45]

im pretty new in this world of cpu can someone tell me the difference if there is one between the master 6801 and the other 2 on the adam board or they can be swap with out prob

 

thanks

 

I know the master is weld on the board just want to know if there something special in the chip

Edited September 29, 2013 by chart45

[JamesD]

Hardware wise they are the same, just different ROM code.

[Dr. D.]

can someone tell me the difference if there is one between the master 6801 and the other 2 on the adam board or they can be swap with out prob

They can't be swapped out, because they have different code inside. Moreover, they are all mask ROMs, manufactured with the program inside, so there is no way to change it. An EPROM version of the microcontroller exists, 68701, for development purposes, but these chips and devices to write them are now rare.

 

If you're interested in the code differences, you can see PDFs of the original source code listings:

 

Master 6801

ADAM printer 6801

Digital Data Drive 6801

 

There is also a 6801 source code archive which has binaries of the above listings, plus binaries and disassembly source code for the ADAM keyboard and prototype serial/parallel device.

 

Chris Braymen was responsible for all of this info (he found the code listings in a back room at Sierra Online Games when he worked there). I did the restoration of the missing page 1 of the ADAM printer source code listing.

 

*Dr. D.*

Edited September 29, 2013 by Dr. D.

[NIAD]

Dr, D... do you have a main page where all this great info you have provided over the years is accessible from. I have multiple links to specific items of your's from the following address, but no main page.

 

http://drushel.cwru.edu/............

[chart45]

 

They can't be swapped out, because they have different code inside. Moreover, they are all mask ROMs, manufactured with the program inside, so there is no way to change it. An EPROM version of the microcontroller exists, 68701, for development purposes, but these chips and devices to write them are now rare.

 

If you're interested in the code differences, you can see PDFs of the original source code listings:

 

Master 6801

ADAM printer 6801

Digital Data Drive 6801

 

There is also a 6801 source code archive which has binaries of the above listings, plus binaries and disassembly source code for the ADAM keyboard and prototype serial/parallel device.

 

Chris Braymen was responsible for all of this info (he found the code listings in a back room at Sierra Online Games when he worked there). I did the restoration of the missing page 1 of the ADAM printer source code listing.

 

*Dr. D.*

ok so there no way to get one of those master chip and no way to reprogram one then is there a way to replace by something else???

 

cause my problem is that I cant get a sgm im on the list for more than a year but no news..... so I try to get the ram to work with my coleco

 

first I try to replace the 2 2114 ram on the coleco by a 6264 chip but that change nothing and now I know that the coleco don't look there for extra ram

 

now I put my hand on a logic module from a adam. then plug in my coleco and its working. remove the 3 rom chip and the 2 6801 chip power on nothing load but when I press reset coleco come on and load game with the extra ram

 

 

now I want to get rid of the logic board and keep only the thing I need to load the extra ram. cause that thing is ok in the garage but really bad in the living room

im not a super tech in computer but im a master mechanic specialize in electrical and a quick learner. can you help me with that little project until I get my sgm

 

sorry my English is not a1

 

thank

Edited September 29, 2013 by chart45

[+5-11under]

To get 24K RAM on the ColecoVision, you need to do the following:

 

Connect the RAM address lines A10 to A14 to the rest of CV circuitry (and of course all the other address, data, write enable, 5V and ground connections).

If you're using a 64K RAM chip, you'll need to either connect the RAM's A15 line to A15 or ground or +5V on the CV.

"AND" Y1bar, Y2bar, and Y3bar (i.e. outputs) of the 74LS138 memory select chip (not the I/O select chip) to the CSbar (or OEbar - there's a preferred option, but either should work) of your RAM. The other of CSbar/OEbar should be connected to ground.

[Dr. D.]

Dr, D... do you have a main page where all this great info you have provided over the years is accessible from. I have multiple links to specific items of your's from the following address, but no main page.

 

http://drushel.cwru.edu/............

Nope, I have never kept an index.html for my webserver, to keep the random traffic down: the machine is old and can't handle too much. Whenever I put something up, I use a direct link to just that stuff, and let the intended people know it's there.

 

I suppose I could collect an ADAM-only pointers page...

 

*Dr. D.*

[NIAD]

I understand that you want to make this RAM mod on a real ColecoVision, but if all else fails, you could pick up a Stand-Alone ADAM Memory Console (the one with the CV built-in, not the Expansion Module #3 ADAM), convert a PC power supply to power the Memory Console and you will have a system that will play some of the SGM games like Dragon's Lair and Zaxxon SuperGame.

 

Unfortunately, any game that checks for the existence of the SGM (ie: King's Valley), will not work on this ADAM setup or your RAM modded CV.

[JamesD]

Actually, someone could probably make a board with a 6803 and an external ROM that plugs in place of the 6801.

The 6803 is basically the same CPU but with no ROM.

 

FWIW, there is also a 6803 core that could be programmed into a CPLD or FPGA.

[Dr. D.]

Actually, someone could probably make a board with a 6803 and an external ROM that plugs in place of the 6801.

The 6803 is basically the same CPU but with no ROM.

The Coleco 160K disk drive does something similar (i.e., external ROM, which is why people were able to clone and modify disk drives), except it uses other Coleco 6801s with failed mask ROMs jumpered to disable the internal ROM. I think that the MI disk drives use 6803s.

 

A long time ago I looked into your idea, but to work it requires that the application not use too many I/O lines that end up being the external address/data lines for the external ROM in 6800/6803 mode. For instance, the keyboard 6801 uses most/all of the I/O lines to drive the keyboard matrix, with nothing left for an external ROM bus. See my poor-quality schematic. (Bob Slopsema may have a better one now.) I think that the prototype serial/parallel unit is in the same boat. That was what I was looking to build, and maybe an external dual-tape unit with devices 9/25 to get D3 and D4 in SmartBASIC.

 

*Dr. D.*

[JamesD]

The Coleco 160K disk drive does something similar (i.e., external ROM, which is why people were able to clone and modify disk drives), except it uses other Coleco 6801s with failed mask ROMs jumpered to disable the internal ROM. I think that the MI disk drives use 6803s.

 

A long time ago I looked into your idea, but to work it requires that the application not use too many I/O lines that end up being the external address/data lines for the external ROM in 6800/6803 mode. For instance, the keyboard 6801 uses most/all of the I/O lines to drive the keyboard matrix, with nothing left for an external ROM bus. See my poor-quality schematic. (Bob Slopsema may have a better one now.) I think that the prototype serial/parallel unit is in the same boat. That was what I was looking to build, and maybe an external dual-tape unit with devices 9/25 to get D3 and D4 in SmartBASIC.

 

*Dr. D.*

It really depends on if I/O ports 3 & 4 are used for I/O or not since those are also the address lines and the ROM code is over 256 bytes.

(A 256 byte or less ROM would only require I/O Port 3)

 

We also have source code so it could certainly be ported to another microcontroller. I'd need to look at the schematics but a PIC controller might be adaptable.

[chart45]

To get 24K RAM on the ColecoVision, you need to do the following:

 

Connect the RAM address lines A10 to A14 to the rest of CV circuitry (and of course all the other address, data, write enable, 5V and ground connections).

If you're using a 64K RAM chip, you'll need to either connect the RAM's A15 line to A15 or ground or +5V on the CV.

"AND" Y1bar, Y2bar, and Y3bar (i.e. outputs) of the 74LS138 memory select chip (not the I/O select chip) to the CSbar (or OEbar - there's a preferred option, but either should work) of your RAM. The other of CSbar/OEbar should be connected to ground.

could you look at this

 

and should i put diode to y1 y2 y3 since they gonna be all in one point

 

and if im wrong could you correct my drawing please cause like i said im not that good in ic im just at the begining

[+5-11under]

Y1, 2 and 3 need to be "AND"ed together, either using a logic chip or diode/resistor logic (http://en.wikipedia.org/wiki/Diode_logic#AND_logic_gate). 10K for the resistor should be fine.

[chart45]

Y1, 2 and 3 need to be "AND"ed together, either using a logic chip or diode/resistor logic (http://en.wikipedia.org/wiki/Diode_logic#AND_logic_gate). 10K for the resistor should be fine.

ok im really not sure about this parts since i dont know if i need to add a ground if this drawing is not good could you draw one for me as a example or write some additional info cause I read and read the wiki link but it's seem that I miss something

 

and witch diode i should use

Edited October 1, 2013 by chart45

[+5-11under]

The grounds are already connected, so that should all be good.

The circuit looks good. Any small signal diode should be fine... 1N914 or 1N4148... or pretty much any regular diode should be fine.

[chart45]

The grounds are already connected, so that should all be good.

The circuit looks good. Any small signal diode should be fine... 1N914 or 1N4148... or pretty much any regular diode should be fine.

thank you I will give a try this week and post result

[chart45]

for now it's a no go the game

load but still get the msg that i need a 8k ram i think ill need help cause in then first post you tell me that i need to hook a0 to a15 but i cant on a 6264 chip do i have to use something else

[chart45]

for now it's a no go the game

load but still get the msg that i need a 8k ram i think ill need help cause in then first post you tell me that i need to hook a0 to a15 but i cant on a 6264 chip do i have to use something else

I think I miss the first part to put a10 to a14 to the rest of the coleco how ??? I cant figure

[+5-11under]

Oh, I assumed the chip was a 64K chip... I'd get a 32K chip, because they're readily available and probably the cheapest. Connect the RAM's A10 to A14 address lines to the same pins on the Z80, for instance. A0 to A9 are presumably already connected, via the old RAM connections.

 

I can't remember if the conversions will work with only 8K RAM... . If yes, use the Y3 (assuming that's the address space used) and connect all the address lines available on the RAM chip.

[chart45]

ok so i should wait to get a 62256 chip before make other change. what is the best option for the chip i will order one

[+5-11under]

ok so i should wait to get a 62256 chip before make other change. what is the best option for the chip i will order one

Just find the cheapest one. If you're retrofitting your first version, make sure the width of the chip is correct (ie. 0.3" or 0.6"). Also verify the pinout - most will be the same as each other, but you never know.

[chart45]

Just find the cheapest one. If you're retrofitting your first version, make sure the width of the chip is correct (ie. 0.3" or 0.6"). Also verify the pinout - most will be the same as each other, but you never know.

i alredy order a 62256 should arrive in the next few days but found this one should i order it cause this one have 18 address

as6c4008 thanks for your help and count me for your pcb

Edited October 3, 2013 by chart45

[chart45]

receive this in the mail today

 

hope that will work

[chart45]

game load but it's slow i dont know if its beacause im on a breadboard or its the chip do you have a idea???

 

and i have to put the oe to rd beacause when i put it to the ground that mess the graphic and again thanks for your advice you re the men

Edited October 5, 2013 by chart45

[chart45]

ok now using 2 62256 ram game load play nice but thant crash or sound bug

 

 

probably because the breadbord but if someone have an idea ???

 

i ordered a 64k chip to replace the 32k should do hope so

 

5-11 can i have your opignion please

Edited October 5, 2013 by chart45